Why character array is better than String for Storing password in Java? Example

Why character array is better than String for storing a password in Java was a recent question asked to one of my friends in a java interview. he was interviewing for a Technical lead position and has over 6 years of experience. Both Character array and String can be used to store text data but choosing one over the other is a difficult question if you haven't faced the situation already. But as my friend said any question related to String must have a clue on a special property of Strings like immutability and he used that to convince the interviewer. here we will explore some reasons why should you use char[] for storing passwords than String.

How to Compare Two Strings Without Case Sensitivity in Java? Example

How to Compare Two Strings Without Case Sensitivity in Java

Java provides several ways to compare strings without taking case sensitivity into account. In this article, we'll explore different methods to perform case-insensitive string comparisons in Java.

Method	Use Case	Efficiency
equalsIgnoreCase()	Checking equality	High
compareToIgnoreCase()	Ordering comparison	High
String.CASE_INSENSITIVE_ORDER	Sorting collections	High
equals() + toUpperCase()	Not recommended	Low

1. Using equalsIgnoreCase()

The equalsIgnoreCase() method

This method is ideal for checking if two strings are equal without considering their case. It returns true if both strings contain the same characters, regardless of their case.

String str1 = "Hello";
String str2 = "hello";
boolean isEqual = str1.equalsIgnoreCase(str2); // Returns true

2. Using compareToIgnoreCase()

The compareToIgnoreCase() method

Use this method when you want to check which string is greater or smaller, or to find out their relative ordering in lexicographical or alphabetical order, without considering case.

String str1 = "Apple";
String str2 = "banana";
int result = str1.compareToIgnoreCase(str2); // Returns a negative value

3. Using String.CASE_INSENSITIVE_ORDER

The String.CASE_INSENSITIVE_ORDER comparator

This comparator is useful for sorting a list of strings in case-insensitive order.

List<String> fruits = Arrays.asList("Apple", "banana", "Cherry");
Collections.sort(fruits, String.CASE_INSENSITIVE_ORDER);
// Result: [Apple, banana, Cherry]

4. Using equals() + toUpperCase()

Combining equals() and toUpperCase()

This is a tricky way to compare two strings in Java in a case-insensitive manner. First, convert both strings to uppercase, then compare them using equals().

String str1 = "Hello";
String str2 = "hello";
boolean isEqual = str1.toUpperCase().equals(str2.toUpperCase()); // Returns true

Note: This method is not recommended as it creates new String objects, which can be inefficient for large-scale comparisons.

Conclusion

When comparing strings without case sensitivity in Java, it's generally best to use the built-in methods like equalsIgnoreCase() for equality checks and compareToIgnoreCase() for ordering comparisons. 

These methods are optimized and provide clear, readable code. For sorting collections of strings, the String.CASE_INSENSITIVE_ORDER comparator is an excellent choice.

Remember, all these methods compare strings in lexicographical order. Choose the method that best fits your specific use case to ensure efficient and accurate string comparisons in your Java applications.

2 Ways to remove whitespaces from String in Java? Example Tutorial

You can remove blanks for whitespaces from a Java String by using the trim() method of java.lang.String class of JDK API. Unlike SQL Server which have LTRIM() and RTRIM() methods to remove whitespace from String, Java doesn't have ltrim() and rtrim() methods to trim white spaces from left and right, instead it just have a trim() method which removes all spaces from String including space at the beginning and at the end. Since String is Immutable in Java, it's worth noting that this method return a new String if original String contains space either at beginning or end, otherwise it will return the same String back. 

Difference in String pool between Java 6 and 7? Answer

String pool in Java is a pool of String literals and interned Strings in JVM for efficient use of String objects. Since String is immutable in Java, it makes sense to cache and shares them in JVM. The String pool has gone through an important change in Java 7 release when it was relocated from PermGen space to heap space. Till Java 1.6, interned String and literals are stored in the PermGen space of JVM memory, which was a fixed size area for storing class metadata. The biggest issue of having a String pool in PermGen is the small and fixed size of PermGen space.

10 Difference between StringBuffer and StringBuilder in Java? [Answered]

Both StringBuffer and StringBuilder are two important classes in Java which represent mutable String i.e. the String object, whose value can be changed. Since String is Immutable in Java, any change or operation on String object e.g. converting it to upper or lower case, adding character, removing a character, or getting a substring, all results in a new String object. This can put a lot of pressure on the Garbage collector if your application generates lots of throws away String instances. To avoid this issue, Java designer presented initially StringBuffer class and later StringBuilder as mutable String. That's the main difference between String vs StringBuffer and StringBuilder and also one of the frequently asked Java questions for beginners.

How to Convert and Print Byte array to Hex String in Java? Example

We often need to convert byte arrays to Hex String in Java, In order to print byte array contents in a readable format. Since many cryptographic algorithms e.g. MD5 return the hash value as a byte array, In order to see and compare that byte array, you need to convert the byte array to Hex String. As we have seen, while generating MD5 checksum of File, there are multiple ways to convert byte array to Hexadecimal String in Java. You can either write your own method, or you can use an open-source library e.g. Apache commons-codec to create Hex String from a byte array in Java. Commons codec provides a utility class Hex, which contains an encodeHexString() method to create Hex String from a byte array.

StringJoiner.join() and String.join() Example in Java 8

Hello guys, joining multiple String literals or objects into one is a common programming requirement and you will often find situations where you need to convert a list of String or a Collection of String into a CSV String for your application. For a long time, JDK API has no way to join multiple String literals or objects together, which forces programmers to write hacks like looping through all String objects and manually joining them using String concatenation to create the final, joined String. Even though this approach worked, it was filled with errors and hacks like you need to be careful not to add delimiter before the first element and after the last element, which often caused issues, particularly in the case of beginners and junior Java developers.

3 ways to convert String to Boolean in Java? Examples

Hello guys, if you ar wondering how to convert a String object to boolean value in Java then don't sweat there are multiple ways to convert a String to Boolean class or boolean value in Java. For Example, ou can convert a String object to a Boolean object or boolean primitive by using the Boolean.valueOf() and Boolean.parseBoolean() method. The steps are similar rot converting to String to other data types  like String to Integer and String to Long. You can use the valueOf() method to convert String to Boolean object and parseBoolean() method to convert a given string to a boolean primitive value. 

Top 15 Java String interview Question Answers for 3 to 5 Years Experienced

10 Java String interviews Question answers
String interview questions in Java is one of Integral part of any Core Java or J2EE interviews. No one can deny the importance of String and how much it is used in any Java application irrespective of whether it's core Java desktop application, web application, Enterprise application or Mobile application. The string is one of the fundamentals of Java programming language and correct understanding of String class is a must for every Java programmer. What makes String interview questions in Java even more interesting is the special status of String in terms of features and privileges it has like the + operator is kind of overloaded to perform String concatenation despite the fact that Java does not support operator overloading. There is a separate String pool to store String literal etc.

How to compare two String in Java - String Comparison Example

String comparison is a common programming task and Java provides several way to compare two String in Java. String is a special class in Java, String is immutable and It’s used a lot in every single Java program starting from simple test to enterprise Java application. In this Java String compare tutorial we will see different ways to compare two String in Java and find out how they compare String and when to use equals() or compareTo() for comparison etc.

Here are four examples of comparing String in Java

1) String comparison using equals method

2) String comparison using equalsIgnoreCase method

2) String comparison using compareTo method

4) String comparison using compareToIgnoreCase method

How to Remove First and Last Character of String in Java - Example Tutorial

You can use the substring() method of java.lang.String class to remove the first or last character of String in Java. The substring() method is overloaded and provides a couple of versions that allows you to remove a character from any position in Java. Alternatively, you can convert String to StringBuffer or StringBuilder and then use its remove() method to remove the first or last character. Both StringBuffer and StringBuilder provides a convenient deleteCharAt(int index) method which removes a character from the corresponding index. You can use this method to remove both first and last characters from String in Java.

How to get first and last character of String in Java - Example

You can get the first and last character of a String using the charAt() method in Java. This method accepts an integer index and returns the corresponding character from String. Since Java String is backed by an array, their index is also zero-based, which means the first character resides at index zero, and the last character is at index, length-1, where length is the number of characters in the String. You can get the length of the String by calling the length() method. The charAt() method is not defined on java.lang.String class, but on its super interface java.lang.CharSequence, hence it will also work for StringBuffer and StringBuilder.

How to check if String is not null and empty in Java? Example

In Java, since null and empty are two different concepts, it's a little bit tricky for beginners to check if a String is both not null and not empty. A String reference variable points to null if it has not been initialized and an empty String is a String without any character or a string of zero length. Remember, a String with just whitespace may not be considered as empty String by one program but considered as empty String by others, so, depending upon your situation, you can include the logic to check for that as well. A String with just white space is also referred to as a blank String in java. In this tutorial, I will teach you a couple of right ways to test if a String is not null and not empty in Java.

When to use intern() method of String in Java? Example

The String.intern() method can be used to deal with the String duplication problem in Java. By carefully using the intern() means you can save a lot of heap memory consumed by duplicate String objects. A String object is said to be duplicated if it contains the same content as another string but occupied a different memory location e.g. str1 != str2 but str1.equals(str2) is true. Since the String object consumes a large amount of heap memory in the average Java application, it makes sense to use the intern() method to reduce duplication and take advantage of the String pool feature provided by Java. You can use the intern() method to intern a String object and store them into the String pool for further reuse.

How to split a comma separated String in Java? Regular Expression Example

You can use the String.split() function or StringTokenizer class to split a comma-separated String in Java. Since splitting a String is a very common functionality, Java designers have provided a couple of split() methods on java.lang.String class itself. These split() function takes a regular expression and split the String accordingly. In order to parse a comma-delimited String, you can just provide a "," as a delimiter and it will return an array of String containing individual values. The split() function internally uses Java's regular expression API (java.util.regex) to do its job.

Why String is Immutable or Final in Java? Explained

The string is Immutable in Java because String objects are cached in the String pool. Since cached String literals are shared between multiple clients there is always a risk, where one client's action would affect all other clients. For example, if one client changes the value of the String "Test" to "TEST", all other clients will also see that value as explained in the first example. Since caching of String objects was important for performance reasons this risk was avoided by making the String class Immutable. At the same time, String was made final so that no one can compromise invariant of String class like Immutability, Caching, hashcode calculation, etc by extending and overriding behaviors. Another reason why the String class is immutable could die due to HashMap.

How to Convert an Array to Comma Separated String in Java - Example Tutorial

The simplest way to convert an array to comma separated String is to create a StringBuilder, iterate through the array, and add each element of the array into StringBuilder after appending the comma. You just need Java 1.5 for that, even if you are not running on Java 5, you can use StringBuffer in place of StringBuilder. The joining of String has got even easier in JDK 8, where you have got the join() method right in the String class itself. The join() method takes a delimiter and a source, which can be an array or collection, and returns a String where each element is joined by a delimiter.

How to remove all special characters from String in Java? Example Tutorial

You can use a regular expression and replaceAll() method of java.lang.String class to remove all special characters from String. A special character is nothing but characters like - ! #, %, etc. Precisely, you need to define what is a special character for you. Once you define that you can use a regular expression to replace those characters with empty String, which is equivalent to removing all special characters from String. For example, suppose, your String contains some special characters e.g. "Awesome!!!" and you want to remove those !!! to reduce some excitement, you can use replaceAll("!", "") to get rid of all exclamation marks from String.

StringTokenizer Example in Java with Multiple Delimiters - Example Tutorial

StringTokenizer is a legacy class for splitting strings into tokens. In order to break String into tokens, you need to create a StringTokenizer object and provide a delimiter for splitting strings into tokens. You can pass multiple delimiters e.g. you can break String into tokens by, and: at the same time. If you don't provide any delimiter then by default it will use white-space. It's inferior to split() as it doesn't support regular expression, also it is not very efficient. Since it’s an obsolete class, don't expect any performance improvement either. On the hand split() has gone some major performance boost on Java 7, see here to learn more about splitting String with regular expression.

How to replace a substring in Java? String replace() method Example Tutorial

You can replace a substring using replace() method in Java. The String class provides the overloaded version of the replace() method, but you need to use the replace(CharSequence target, CharSequence replacement). This version of the replace() method replaces each substring of this string (on which you call the replace() method) that matches the literal target sequence with the specified literal replacement sequence. For example, if you call "Effective Java".replace("Effective", "Head First") then it will replace "Effective" with "Head First" in the String "Effective Java". Since String is Immutable in Java, this call will produce a new String "Head First Java".

How to check if String contains another SubString in Java? contains() and indexOf() example

You can use contains(), indexOf() and lastIndexOf() method to check if one String contains another String in Java or not. If a String contains another String then it's known as a substring. The indexOf() method accepts a String and returns the starting position of the string if it exists, otherwise, it will return -1. For example "fastfood".indexOf("food") will return 4 but "fastfood".indexOf("Pizza") will return -1. This is the easiest way to test if one String contains another substring or not.

How to check if a String is numeric in Java? Use isNumeric() or isNumber() Example

In day-to-day programming, you often need to check if a given string is numeric or not. It's also a good interview question but that's a separate topic of discussion. Even though you can use Regular expression to check if the given String is empty or not, as shown here, they are not full proof to handle all kinds of scenarios, which common third-party libraries like Apache commons-lang will handle e.g. hexadecimal and octal String. Hence, In the Java application, the simplest way to determine if a String is a number or not is by using the Apache Commons lang's isNumber() method, which checks whether the String is a valid number in Java or not.

How to split String in Java by WhiteSpace or tabs? Example Tutorial

You can split a String by whitespaces or tabs in Java by using the split() method of java.lang.String class. This method accepts a regular expression and you can pass a regex matching with whitespace to split the String where words are separated by spaces. Though this is not as straightforward as it seems, especially if you are not coding in Java regularly. Input String may contain leading and trailing spaces, it may contain multiple white spaces between words and words may also be separated by tabs. Your solution needs to take care of all these conditions if you just want words and no empty String.

Java String Replace Example Tutorial

This String replace example in Java will show you how to replace String in Java both at the character level and by using regular expression. Since String is final in Java every time you replace String you will get a new String object only if your actually replace anything on original String otherwise replace methods of String return same String object. String Class in Java provides 4 methods to replace String in Java. Those methods allow you to replace character from String, replace CharacterSequence from String, replace all occurrence of pattern in String or just first occurrence of any pattern in Java.

How SubString method works in Java - Memory Leak Fixed in JDK 1.7

Substring method from the String class is one of the most used methods in Java, and it's also part of an interesting String interview question e.g. How substring works in Java or sometimes asked as to how does substring creates memory leak in Java. In order to answer these questions, your knowledge of implementation details is required. Recently one of my friends was drilled on the substring method in Java during a Java interview, he was using the substring() method for a long time, and of course, all of us has used this, but what surprises him was the interviewer's obsession on Java substring, and deep-dive till the implementation level.

How to use String in switch case in Java with Example

Have you ever feel that String should be used in switch cases like int and char? JDK 7 has made an important enhancement in their support of String, now you can use String in switch and case statements, No doubt String is the most widely used type in Java, and in my opinion, they should have made this enhancement long back when they provided support for enum in java and allowed enum to be used in a switch statement. 

How to String Split Example in Java - Tutorial

Java String Split Example
I don't know how many times I needed to Split a String in Java. Splitting a delimited String is a very common operation given various data sources e.g CSV file which contains input string in the form of large String separated by the comma. Splitting is necessary and Java API has great support for it. Java provides two convenience methods to split strings first within the java.lang.String class itself: split (regex) and other in java.util.StringTokenizer. Both are capable of splitting the string by any delimiter provided to them. Since String is final in Java every split-ed String is a new String in Java.

How to convert String or char to ASCII values in Java - Example Tutorial

You can convert a character like 'A' to its corresponding ASCII value 65 by just storing it into a numeric data type like byte, int, or long as shown below :

int asciiOfA = (int) 'A';

Here casting is not necessary, simply assigning a character to an integer is enough to store the ASCII value of character into an int variable, but casting improves readability. Since ASCII is a 7-bit character encoding, you don't even need an integer variable to store ASCII values, byte data type in Java, which is 8 bits wide is enough to store the ASCII value of any character.  So you can also do like this :

byte asciiOfB = 'B'; // assign 66 to variable

How to format String in Java – String format Example

String format and printf Example

How to format String in Java is the most common problem developers encounter because of classic System.out.println() doesn’t support formatting of String while printing on console. For those who don’t know What is formatted String? here is a simple definition,  Formatted String is a String that not only displays contents but also displays it in a format that is widely accepted like including comma while displaying large numbers e.g. 100,000,000, etc. Displaying formatted String is one of the needs for modern GUI applications and thankfully Java has good support for formatting String and all other types like Integers, Double, and Date. 

How String in Switch works in Java? Example

Ever Since Java allows using String variables in switch and case statements, there are many programmers using this feature in code, which can be better written using integer and enum patterns. This was one of the popular features of the JDK 7 release, including automatic resource management and multi-exception catch blocks. Though I upfront didn't like this feature because of the better alternatives available in terms of using the enumeration type, I am not totally against this feature. One reason for this is convenience and given usage of String in Java program, it's quite handy as well, but I prefer to learn more before using any new feature in production code.

10 Things Every Java Programmer Should Know about String

String in Java is a very special class and the most frequently used class as well. There are lot many more things to learn about String in Java than any other class, and having a good knowledge of different String functionalities makes you use it properly. Given the heavy use of Java String in almost any kind of project, it becomes even more important to know subtle detail about String. Though I have shared a lot of String related articles already here in Javarevisited, this is an effort to bring some of the String features together. 

How to Split String based on delimiter in Java? Example Tutorial

You can use the split() method of String class from JDK to split a String based on a delimiter e.g. splitting a comma-separated String on a comma, breaking a pipe-delimited String on a pipe, or splitting a pipe-delimited String on a pipe. It's very similar to earlier examples where you have learned how to split String in Java. The only point which is important to remember is little bit of knowledge of regular expression, especially when the delimiter is also a special character in regular expression e.g. pipe (|) or dot (.), as seen in how to split String by dot in Java. In those cases, you need to escape these characters e.g. instead of |, you need to pass \\| to the split method.

String replaceAll() example - How to replace all characters and substring from String

You can replace all occurrence of a single character, or a substring of a given String in Java using the replaceAll() method of java.lang.String class. This method also allows you to specify the target substring using the regular expression, which means you can use this to remove all white space from String. The replaceAll() function is a very useful, versatile, and powerful method and as a Java developer, you must know about it. Even though Java provides separate methods for replacing characters and replacing substring, you can do all that just by using this single method.

Top 10 Low Latency Tips for Experienced Java Developers

Hello guys, If you are preparing for interviews at High-Frequency Trading (HFT) firms, hedge funds, investment banks, or crypto exchanges, then one thing is guaranteed: You will be asked about low latency systems. Building such systems is a completely different ball game. It’s not just about writing clean code — it's about writing fast code that responds in microseconds. I’ve worked on low-latency Java applications that run in production under tight time constraints, and in this post, I’ll share what I’ve learned in easy Indian English, with some practical examples.

Difference between Stack and Heap memory in Java? Example

The difference between stack and heap memory is a common programming question asked by beginners learning Java or any other programming language. Stack and heap memory are two terms programmers start hearing once they started programming but without any clear and definite explanation. Lack of knowledge of what is a heap in Java and what is stack memory in Java results in misconceptions related to stack and heap. To add to this confusion, a stack is also a data structure that is used to store elements in LIFO(Last In First Out) order and is available in Java API as java.util.Stack.

What is load-on-startup servlet element in web.xml with Example?

load-on-startup is an element that appears inside <servlet> tag in web.xml.4 years back load-on-startup was a very popular servlet interview question because not many Java J2EE developer was familiar with this element and how load-on-startup works inside a servlet container like tomcat or WebSphere. In this J2EE Tutorial, we will see what is a load on startup, how to use the load-on-startup element, and what are different values we can configure for load-On-Startup inside web.xml.

Difference between SendRedirect() and Forward() in JSP Servlet? Example

The difference between SendRedirect and forward is one of the classical interview questions asked during a java web developer interview. This is not just applicable for servlet but also for JSP in which we can use forward action or call sendRedirect() method from scriptlet. Before examining the difference between forward and SendRedirect let’s see what send Redirect method and the forward method does.

SendRedirect ():  

This method is declared in HttpServletResponse Interface.

Signature: void sendRedirect(String url)

Difference between throw and throws in Exception handling - Java Example

Difference between throw and throws keyword on Exception handling in Java is a popular core java interview question. Exception handling being an important part of Java programming language, complete knowledge of all keywords related to exception handling e.g. try, catch, finally, throw and throws is important. Main difference between throw and throws is in there usage and functionality. where throws is used in method signature to declare Exception possibly thrown by any method, throw is actually used to throw Exception in Java code, here is an example of both throw and throws keyword which makes it easy to understand difference between them.

Difference between Struts 1 and Struts 2 Web Development Framework

I had worked previously on Struts 1 but never touched Struts 2, especially since Spring MVC was there to take the leading role. Recently one of my friends ask me to help with Struts2, which leads me to look on the Struts2 framework from start. First thing I wanted to find out differences between Struts 1 and Struts 2 framework, because in my experience, if you have worked in the previous version looking differences between two versions of Struts can quickly help to find, what changes and What are the new features, concepts and improvement is offered by Struts 2. Also the difference between Struts 1 and Struts 2 is a good candidate to include in my list of Struts interview questions for quick revision.

10 points on finalize method in Java – Tutorial Example

finalize method in java is a special method much like the main method in java. finalize() is called before the Garbage collector reclaims the Object, its last chance for any object to perform cleanup activity i.e. releasing any system resources held, closing the connection if open etc. The main issue with finalize() method in Java is it's not guaranteed by JLS that it will be called by Garbage collector or exactly when it will be called, for example, an object may wait indefinitely after becoming eligible for garbage collection and before its finalize() method gets called. similarly even after finalize gets called it's not guaranteed it will be immediately collected.

What is Static and Dynamic binding in Java with Example

Static and dynamic binding in Java is two important concepts that Java programmer should be aware of. this is directly related to the execution of code. If you have more than one method of the same name (method overriding) or two variables of the same name in the same class hierarchy it gets tricky to find out which one is used during runtime as a result of their reference in code. This problem is resolved using static and dynamic binding in Java. For those who are not familiar with the binding operation, its process is used to a link which method or variable to be called as a result of their reference in code.

3 Examples to Concatenate String in Java

String concatenation is the process of joining two or more small String to create a big String. For example, you can create a full name by concatenating first and last name of a person. Java provides multiple ways to concatenate String, but the easiest of them is by using + operator. It is one of the magical operators in Java, though Java doesn't support operator overloading, it has made an exception in the case of String and + operators.  Plus operator is a binary operator and primarily used to add two numbers if both operands are integer but it can also used to concatenate String if either both or first operand is String. For example, "Java" + "Programming" will produce "JavaProgramming".

3 Ways to Convert an Array to ArrayList in Java? Example

How to convert an Array to ArrayList in Java
Have you encountered any situation where you quickly wanted to convert your array to ArrayList or ArrayList to array in Java? I have faced many such situations that motivate me to write these quick Java tips about converting an array to ArrayList and ArrayList to array in Java. Both array and ArrayList are quite common and every Java developer is familiar with this. Former is used to store objects and primitive types while later can only hold objects. The array is part of standard Java fundamental data structure while ArrayList is part of the collection framework in Java.

How to Replace Line Breaks , New Lines From String in Java - Windows, Mac or Linux Example

We often need to replace line terminator characters, also known as line breaks e.g. new line \n and carriage return \r with different characters. One of the common case is to replace all line breaks with empty space in order to concatenate multiple lines into one long line of String. In order to replace line breaks, you must know line terminator or new line characters for that platform. For example, In Windows operating system e.g. Windows 7 and 8, lines are terminated by \n\r  also known as CR+LF, while in Unix environment e.g. Linux or Solaris line terminator is \n, known as line feed LF. You can also get line terminator pragmatically by using Java system property line.terminator.

How to Convert Byte Array to InputStream and OutputStream in Java? Example

Are you stuck with your coding because you have a byte array and the next method in the chain needs an InputStream? don't worry Java has a solution for that, You can use ByteArrayInputStream to convert byte array to InputStream in Java. This class takes a byte array as the source and since it's a subclass of InputStream, you can easily pass this to any method, which accepts InputStream as a parameter. Though most of the API like JDBC and File API allows you to read directly from InputStream because this allows you to process an arbitrary content with limited heap space. You should take advantage of this and directly read from InputStream instead of getting byte array and then converting them back to InputStream.

How to Convert InputStream to Byte Array in Java - 2 Examples

Sometimes we need to convert InputStream to byte array in Java, or you can say reading InputStream as a byte array, In order to pass output to a method that accepts byte array rather than InputStream. One popular example of this, I have seen is an older version of Apache commons-codec, while converting byte array to the hex string. Though, a later version of the same library does provide an overloaded method, to accept InputStream. Java File API provides excellent support to read files like image, text as InputStream in Java program, but as I said, sometimes you need String or byte array, instead of InputStream .

How to Reverse Array in Place in Java? Solution With Explanation

Reversing an array sounds pretty easy, isn't it? It does sound like that, because all you need to do is create an array of the same size, iterate through the original array from end to start, and populate your new array. Boom!!, you have got an array that has elements in reverse order of the original array, but the problem is you have used an additional array here, which makes space complexity of your solution O(n). You cannot use this solution if the array is big e.g. an array of 10 million orders and you don't have enough heap space available.

How to Convert List of Integers to Int Array in Java - Example

So, you have a List of Integers and you want to convert them into int array? Yes, you read it write, not on Integer array but int array. Though in most practical purpose, Integer array can be used in place of int[] because of autoboxing in Java, you still need an int[] if your method accepts it. In Java, you can not typecast an Integer array into an int array. Many Java programmer think about toArray() method from java.util.List to convert a List into Array, but unfortunately, toArray() is useless most of the time. It doesn't allow you to convert List into primitive arrays.

How to Generate MD5 Hash in Java - String Byte Array Digest Example

There are multiple ways to generate the MD5 hash in Java program. Not only Java API provides a convenient method for generating MD5 hash, you can also use popular open-source frameworks like Spring and Apache commons Codec to generate MD5 digest in Java. MD5 is a popular Message-Digest Algorithm, which is most commonly used to check data integrity e.g. comparing MD5 checksum to see, if any file is altered or not. Though MD5 has not considered a good cryptographic algorithm for security purposes due to several vulnerabilities found on it, it's still good enough or checking the integrity of the file. MD5 hashing algorithm generates a 128 bit or 16-byte long hash value.

Top 5 Courses to Learn JIRA for Beginners and Experienced in 2025 - Best of Lot

Hello guys, If you are working in Agile projects, you must have come across JIRA, one of the most popular tools for planning, project management, and bug tracking. Almost all software companies use JIRA for their software development, making it an essential tool for software developers, team lead, tech lead, scrum master, and project managers. If you want to learn JIRA and look for the best online training courses, you have come to the right place. In the past, I have shared free Agile courses and books, and  In this article, I will share the best courses to learn JIRA online for both beginners and experienced developers.

Is IBM Data Analyst Professional Certificate on Coursera worth it in 2025? [Review]

Hello guys, if you want to become a Data Analyst in 2025 and looking for the best online resources to learn Data Analysis essentials and kick start your career then you have come to the right place. Earlier, I have shared the best Data Analysis Courses for beginners and in this article, I am going to introduce you to one of the most popular Data Analyst certifications from Coursera, IBM's Data Analyst Professional Certification.  If you don't know Coursera brings the best learning material and resources from top companies like IBM and Google as the world's top universities like the University of Michigan and Stanford. Their Professional certifications are also well recognized and well structured to learn in-demand tech skills and this is one of them. 

Top 5 Courses to Learn Visual Studio Code IDE for Coding & Web Development in 2025 - Best of Lot

Hello guys, if you want to learn VS code and look for the best online courses and tutorials, you have come to the right place. In the past, I have shared the best Eclipse IDE courses and best courses to learn IntelliJ IDEA, and in this course, I will share the best online course to learn VS code, one of the most popular free code editors in 2025. If you are doing web development or programming, you might have heard about VS Code or Visual Studio Code, one of the best modern IDE from Microsoft for current developers. Visual Studio Code is a fast and lightweight cross-platform code editor for writing modern web and cloud applications. You can use VS Code not only on Windows but also on Mac. 

Top 10 Edureka Courses & Certifications for Java and Web Developers in 2025 - Best of Lot

Hello guys, if you are looking for the best Edureka courses to join in 2025, then you have come to the right place. Earlier, I shared the best Udemy courses and Pluralsight courses, and in this article, I will share the best Edureka certification courses to join in 2025. If you like online classroom training, you may hear about Edureka, the online live classroom training leader. Online classroom training is a bit different from online courses. You will get an opportunity to interact with instructors live; it's much closer to traditional classroom learning in school and colleges than online courses.  Because of this unique teacher-student interaction, online classroom teaching is becoming more popular every passing day. 

Top 10 Free AWS Courses on Udemy For Beginners in 2025 - Best of Lot

Since you're here reading this article, I am assuming that you all want to learn more about AWS. But before we get to the best 10 free courses that will teach you all about AWS, let me tell you what AWS really is, okay?  AWS, or Amazon Web Services, is the leading cloud provider in the industry right now. It gives developers more than 170 AWS services that they can access from anywhere in the world. AWS has customers in more than 190 countries all over the world. 

Top 10 Free Eclipse and IntelliJ IDEA Courses for Java Developers in 2025 - Best of Lot

Hello guys, if you are doing Java development and want to learn Eclipse or IntelliJ IDEA, two of the most popular Java IDE and looking for online resources then you have come to the right place. Earlier, I have shared best paid Eclipse courses and best paid IntelliJ IDEA courses but a lot of you asked for free courses so here we are today. In this article, I am going to share best free online courses to learn both Eclipse and IntelliJ IDEA for Java development. But, before we get to the 10 best free courses that will teach you everything you need to know about Eclipse and IntelliJ, let me tell you a little bit about what it all is. Both Eclipse and IntelliJ are basically IDEs or Integrated Development Environments. 

10 Free TypeScript Courses for Beginners in 2025

Hello guys, if you want to learn TypeScript, the language of web development and the one which i used in Angular framework and looking for online resources like online courses, books, and tutorials then you have come to the right place. Earlier, I have shared best TypeScript paid courses and books and in this article I am going to share best free online courses to learn TypeScript in 2025. But, before we get to a list of the best free courses that will teach you everything you need to know about TypeScript, let me tell you a little bit more about what it really is. For those of you who don't know, TypeScript is basically a strongly typed superscript of JavaScript. It can be compiled to plain JavaScript. TypeScript can be used for application-scale JavaScript development. It can also be executed on any browser, any host, and any operating system.

Top 5 Free Courses To Learn Terraform in 2025 - Best of Lot

Hello guys, if you want to learn Terraform, one of the essential DevOps tool for Infrastructure as code then you have come to the right place. Earlier, I have shared best paid Terraform online courses and in this article, I am going to share best free Terraform online courses in 2025. If you want to learn Terraform online, for free then you can join these courses and learn this useful tool in 2025. Terraform is one of the leading tool in DevOps space along with Docker, Kubernetes, Ansible, and Jenkins. I was actually researching all the new innovations in the tech industry when one of my friends, who is a DevOps Engineer, told me about the Infrastructure as Code (IaC) concept. I am pretty sure that if you are a DevOps Engineer or someone who works in a related field, you will be pretty familiar with this concept. But for those of you who don't know what it is, don't worry. I have got your back.

7 Free CI/CD and Jenkins Courses for Java Programmers in 2025 - Best of Lot

Hello guys, if you want to learn Jenkins and CI/CD and looking for free resources then you have come to the right place. Earlier, I have shared best DevOps Courses and best CI/CD courses and today, I am going to share best free online courses to learn Jenkins and CI/CD (Continuous Integration and Continuous Delivery). But, before we get to the 7 best free courses that will teach you everything you need to know about Jenkins and CI/CD, let me tell you a little bit about what it really is. You can think of Jenkins as an open-source automation tool that is written in Java and it allows Java developers and DevOps Engineers to create pipelines. 

Top 6 Courses to Learn Data Structures and Algorithms in C++ - Best of Lot (2025)

Hello guys, if you want to learn Data Structures and Algorithms in 2025 then you have come to the right place. This is one topic which I believe every programmer should learn in depth. In the past, I have shared best data structure courses and books which were aimed towards Java developers and in this article, I am going to share best online courses to learn Data Structures and Algorithms for C and C++ developers. But, before we get to the 5 best courses that will teach you everything you need to know about data structures in C and C++, let me tell you a little bit about C, C++, and what role data structures play in these two programming languages.

Top 5 Online Courses to Learn Ethical Hacking in 2025 - Best of Lot

Hello guys, if you want to learn Ethical Hacking in 2025 and are looking for the best resources like online courses, you have come to the right place. Earlier, I shared the best Cyber Security courses, and in this article, I have shared the best Ethical Hacking courses for beginners and experienced IT professionals. If you don't know, Ethical hacking is the process of testing your system's infrastructure or network for vulnerabilities and locating its weaknesses to close those vulnerabilities and make your systems more secure. These are very in-demand skills, and there is a lot of job for Ethical hackers as companies, both big and small are grappling with security threats and always looking to find and close any vulnerabilities they might have. 

7 Best Free Datacamp Courses to Learn Online in 2025 [UPDATED]

Hello guys, if you are looking for free Datacamp courses to learn in-demand tech and data skills like Python, SQL, Data Science, Tableau, Data Analysis, etc then you have come to the right place. Earlier, I have shared, best DataCamp courses for Beginners and in this article, I am going to share the best free Datacamp courses to learn Python, SQL, and Data skills. If you don't know, Datacamp is one of the most popular websites for learning Data skills. Their interactive and hands-on courses make learning really easy and that's why both beginners and intermediate data scientists join Datacamp. 

Top 5 CompTIA Server+ Certification Exam Courses and Practice Tests in 2025 - Best of Lot

Hello guys, If you are preparing for CompTIA Server+ certification and looking for the best online training courses and practice test then you have come to the right place. In the past, I have shared the best online courses to pass CompTIA certifications like CompTIA A+, Cloud+, and Security+  and In this article, I am going to share the best courses, practice tests, and exam simulator to prepare for this prestigious exam. These online courses have been created by experts and thousands of Server+ certification aspirants have joined this course. If you are also serious about passing the CompTIA Server+ exam on the first attempt, you should check out them and enroll in at least one course and one practice test for solid preparation.

Google Protocol Buffers (ProtoBuf) - Best Alternative to Java Serialization

If you have done some serialization works in Java, then you know that it's not that easy. Since the default serialization mechanism is not efficient and has a host of problems, see Effective Java Item 74 to 78, it's really not a good choice to persist Java object in production. Though many of the efficiency shortcomings of default Serialization can be mitigated by using a custom serialized format, they have their own encoding and parsing overhead. Google protocol buffers, popularly known as protobuf is an alternate and faster way to serialize Java objects. It's probably the best alternative to Java serialization and useful for both data storage and data transfer over the network.

Student Management System Project - FullStack Java + Spring Boot + React.js Example Tutorial

Hello Java programmers, if you want to learn Spring Boot and Reactjs and looking for a full-stack Java example or a mini project then you have come to the right place. Earlier, I have shared the best Spring Boot courses, books, and best reactjs courses as well as many courses to learn full-stack development in Java and become a full-stack java developer. In this mini project, you will learn how to create an application that is capable of creating, deleting, updating, and retrieving functions using the Spring Boot, React, and H2 Database. In this tutorial you will create a School Classroom Application that can insert, update, delete and search students. The frontend of the application is developed using Reactjs and also the backend is developed using spring boot. And, most importantly communication between the two platforms will be done using the REST APIs. 

10 Programming Best Practices to Name Variables, Methods and Class in Java - Examples

What's in a name? "A rose by any other name would smell as sweet" is a famous quote from William Shakespeare's classic Romeo and Juliet, but sorry to say, name matter a lot in programming and coding.  It's also said that code is the best document for any software because any other document or comments can become outdated quickly, but code will always tell you the truth. And, If code is the best document then names are the most critical element of it. Every effort, small or big, invested while naming variables or methods, pays in both the short term and long term. In fact, if you ask me just one coding practice to follow, I would definitely recommend giving meaningful names to your variables and methods.

10 Tips to Learn a New Project or Codebase Quickly

One of the main drawbacks of changing a job or changing a project is that you lost all subject matter expertise you have learned by working the last couple of years in that project or domain. It doesn't matter whether you are an expert in a programming language like Java or Python, once you change jobs, you lost your hard-earned experience on projects or domains you are working on. When starting a new job or on to a new project you will rarely be working in a complete greenfield environment. Understanding and mastering an unfamiliar code is a difficult process and it can sometimes feel overwhelming due to the amount of new information you need to take on.

10 Things to Remember while doing Database Server Migration in Production

Hello guys, recently, I have to work on a high profile project which involves migrating a live database from one server to another server as part of their data center exit program. This was one of the critical projects to pull off because we can't afford any mishap or data loss or production outage. There are a lot of things that I learned and would like to share with you guys. All these lessons not just apply to migrate databases like Microsoft SQL Server, Oracle, or MySQL database from one server to another but to any production process, you are migrating from another server. These are the things we learn from experience but as I have said in the past, you can only learn a few things

Difference between Inheritance and Composition in Java and Object Oriented Programming

Though both Inheritance and Composition provide code reusability, the main difference between Composition and Inheritance in Java is that Composition allows reuse of code without extending it but for Inheritance, you must extend the class for any reuse of code or functionality. Another difference that comes from this fact is that by using Composition you can reuse code for even the final class which is not extensible but Inheritance cannot reuse code in such cases. Also by using Composition, you can reuse code from many classes as they are declared as just a member variable, but with Inheritance, you can reuse code from just one class because in Java you can only extend one class because multiple Inheritance is not supported in Java.

Why use Cloud Computing? Advantages and Disadvantages

Hello guys, If you are curious about Cloud computing and why every company, both big and small, is going to be cloud-native, you have come to the right place. In the past, I have shared the best Cloud Computing courses and both free and paid courses to learn about popular cloud platforms like AWS, GCP, and Azure. In this article, I am going back to basics and telling you about what is cloud computing and what benefits it offers. Cloud Computing has been a buzzword in the IT world for the last few years. When it first appeared, like many things, a lot of people has dismissed it as being the next big thing, but cloud computing has certainly lived up to expectations and truly shifted how the Information technology arm of business functions today.

10 Tips to create Maintainable Java Applications

Hello all, if you are in software development then you know that creating an application is easy but creating a maintainable application that can pass the test of time in production is rather difficult and that's the main reason experienced Sofware developers are paid higher salaries compared to many other jobs. In this article, I am going to share with you some tips on creating maintainable Java applications which will help you not just in the new year, but also in all the coming years in your software development career.  One aspect of development, which is often overlooked by developers is to create applications that are both easy to maintain and support. Since software spends 90% of its lifetime in maintenance mode, it's very important that your application is easy to configure, support, and maintain. 

Why Static Code Analysis is Important? Pros and Cons

In the last few years, Software code quality and security have gone from being a “nice to have” to a necessity, and many organizations, including investment banks, are making it mandatory to pass static code analysis tests, penetration testing, and security testing before you deploy your code in production. Static analysis tools like findbugs and fortify are getting popular every passing day and more and more companies are making fortify scan mandatory for all new development.  For those unaware of what static code analysis is, static code analysis is about analyzing your source code without executing them to find potential vulnerabilities, bugs, and security threats.

Top 23 Design Patterns Experienced Java Programmers Should Learn

Hello guys, if you want to learn Design Patterns and looking for a comprehensive tutorial which covers all important object oriented design pattern then you have come to the right place. Earlier, I have shared best Design pattern courses and books for experienced developers and in this article, I will introduce you with 23 common object oriented design patterns for writing better code. Design Patterns are tried and tested way of solving a problem within a given context. They are not invented, rather they are discovered, which is also obvious by use of word pattern. By using design pattern, you take knowledge of all wide communities and can safely use it to solve that problem. At times they might not give you perfect solution, require bit of tweaking, but they certainly provides one of the best solution, as long as you use them properly. While doing object oriented development, they are numerous task which appears quite often e.g. creating objects, structuring code, and implementing different behaviors based on different context.

Top 5 Cloud Computing Platforms Java Programmers Should Know

Cloud computing is Hot, it's the biggest IT trend of the last few years and will continue to grow strong in the coming future. Cloud computing provides several not-so-easy-to-ignore advantages, especially to public and small enterprises, which cannot afford to own and maintain expensive data centers. Since most online businesses nowadays need high availability, scalability, and resiliency, with-in a quick time, it's not possible to achieve all these on your own, and cloud computing becomes the best alternative here. Cloud service providers like Amazon Web Services (AWS) has helped several firms to remain focus on their business, without worrying for IT and infrastructure too much, this has yield big result for them.

How Long does It take To Learn Linux?

Hello guys, if you want to learn Linux but not sure how to start then you have come to the right place. Earlier, I have shared best places to learn Linux and best Linux books for beginners and Linux interview questions with answers and in this article, I Am going to share the best way to learn Linux and answer frequently asked question, how long does it take to Learn Linux. In general, you can learn Linux in one weekend but it can take weeks before you become a Linux master as there are a lot of Linux commands and concepts to master. In this article, I will answer this question objectively depending upon your goal, for example, for a developer it can take a  week to Learn Linux but for System Admin it could be months because they need more in-depth knowledge. 

Top 10 Most Popular Programming Languages of the Last 50 Years and their Inventors

There are many programming languages out there in the software world, and they are still coming like Scala, Go, TypeScript, Rust, etc., but only a handful of them have managed to survive to date. These are the ones who have contributed immensely to software development. Since programming language is the single most important thing in the software development world, it's often discussed, criticized, and improved over the years. Programmers and developers, who those programming languages are icons of the programming world and sometimes I feel sad when a guy using a programming language doesn't know, who is behind that.