Why Java and Spring Developers Should Learn RESTful Web Services and Microservices

More and More companies are adopting  Microservices architecture e.g. Uber and Netflix already uses it and many startups I know is choosing REST and MicroService as the standard way to build and provide their services. This is fueling the demand for programmers who can develop robust and scalable Microservices and RESTful Web Services. Since Java is one of the most popular language for developing backend, it is also benefiting from this trend. The demand for Java developers who knows Spring framework and understand how to build RESTful web services is huge and that's why it has become a key skill in Java application development job market. 

15 Example of print() and println() methods in Java

Hello guys, if you have learned Java in early 2000 then there is  good chance that you must have written your first Java code using System.out.println(). For a long time, I have no idea what that mean but I alway use it to print messages on console. When I started working in Java and preparing for Java certification then I come to know that System is a class and out is an object of PrintStream which has println() method. That was a revelation for me. I also found that Java provides a powerful set of I/O classes for handling various input and output operations. Among these, the PrintStream class stands out as a versatile tool for writing formatted text to output streams. The print(), printf() and println() methods within the PrintStream class, as well as System.out.println(), are particularly useful for printing different types of data to the console or other output destinations.

How to fix Eclipse - Could not reserve enough space for object heap in Java? Solution

If you are running Java program in Eclipse and ever tried playing with -Xmx parameter you know about those virtual machine initialization error e.g. "“Error occurred during initialization of VM; Could not reserve enough space for object heap”. This error usually occur when you to try to give your program, running on 32-bit JVM more than 1.4G of memory in Eclipse in Windows. It doesn't matter how much memory your machine have e.g. I have seen this error in laptops running 4GB of memory. The important thing which matter is whether JRE or JVM you are using with Eclipse is 32-bit or 64-bit. If you use 64-bit JRE in Eclipse, you can potentially allocate more than 1.4G of memory in Windows itself.

How to fix java.net.SocketException: Connection reset by peer: socket write error? [Solved]

"Exception in thread "main" java.net.SocketException: Software caused connection abort: socket write error" comes when you are writing into a connection which is already closed by your peer i.e. the other party in the connection. For example, if you are server and sending response to client but client closed its connection before you complete writing response, the write() method of DataOutputStream will throw this error. It's not necessary that this error will only come when you are using DataOutputStream, it can come even if you are just using and OutputStream or SocketOutputStream point is you are writing in a socket which is closed by other end. Here is the actual error message with stacktrace:

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. 

How does Remember Me functionality works in Spring Security?

In the last article, You have learned how to enable the remember-me functionality in Spring security and today you will learn how does Remember Me work under the hood. So far, you know that remember-me functionality uses cookie to remember users and allow auto-login (without entering password again), so you might have guessed that spring security provides hooks to generate that cookie as well as process those cookie when an already signed user open the application after the break e.g. after a day or two. As long as cookie is not expired and token is valid i.e. user hasn't changed the password, he should be able to login to your application. 

6 ways to sort ArrayList in Java 8? List.sort() + Collections.sort() Example Tutorial

There are many ways to sort an ArrayList in Java 8; for example. you can use the old but still rocking way to sort a List by using Collections.sort() method, or you can use the newly added sort() method in the List interface in Java, or you can use the new java.util.stream API to sort a list of objects. You now have multiple choices when it comes to sort a List or Array in Java. Though, my preferred way is Collections.sort() method because it is available to all the Java versions and its easy to use and it also allows you to sort in any custom order.  The method is overloaded which gives you ability to sort a list of objects into their natural order as well allow you to supply a Comparator of your choice to sort elements into customer order. 

How to enable RememberMe Functionality in Spring Security

Hello guys, most of the web application has login or authentication functionality where user need to enter their username and password to access functionalities provided by application. This is great from application's perspective because functionalities are protected from anonymous user but from user's perspective he would appreciated something which would not ask him/her to enter username and password every now and then. This is what remember me functionality of Spring security does. It allow you to build a web application which can remember their user and allow them to automatically login when the restart their browser or come back another day.