How to Fix Access restriction: The type BASE64Decoder is not accessible due to restriction Error in Eclipse? [Solution]

Hello guys, if you have been using Eclipse for Java development then you might have seen this dreaded  "Access restriction: The type BASE64Decoder is not accessible due to restriction Error" before. This error comes when you are trying to encode String into Base64 using BASE64Decoder in Eclipse because the class BASE64Decoder is not part of JDK's public API, it comes from sun.misc package which is non-public. Though this class is present in JDK and JRE and allows you to encode and decode String into base 64, any access to this class from Eclipse flags as an error in Eclipse IDE. If you compile and run the same program from the command line or NetBeans you will not get this error.

Eclipse and NetBeans Keyboard Shortcuts for Java Programmers - Example

If you are a Java developer who has been using Eclipse for Java development, but you need to use Netbeans for your current project for various reasons, this article is for you. Whenever we transition between tools, we need the equivalent of one into other. For example, if you are an Eclipse power user who is used to Ctrl + Shift + R and Ctrl + Shift + T, you miss those as soon as you start using Netbeans shortcuts. One thing to keep your productivity up is to quickly find the equivalent shortcut in a new tool, like, Netbeans if you are switching from Eclipse or vice-versa.

How to Fix Unsupported major.minor version 60.0, 59.0, 58.0, 57.0, 56.0, 55.0, 54, 0, 53.0, 52.00, 51.0 Error in Eclipse & Java

The UnsupportedClassVersionError is a big nightmare for Java developers, probably the next biggest after NoClassDefFoundError and ClassNotFoundException but it's slightly easier to solve. The root cause of this error is that your code is compiled using a higher JDK version and you are trying to run it on the lower version. For example, the Unsupported major.minor version 53.0 means your code is compiled in JDK 9 (the class version 52 corresponds to JDK 9) and you are trying to run it on any JRE lower than Java 9, probably JDK 8, 7, or 6.

Top 6 Free Udemy Courses to Learn Eclipse and JUnit for Beginners in 2025 - Best of Lot

Both Eclipse and JUnit are two of the essential tools for Java Developers. Eclipse is a Java IDE, Integrated Development environment which allows you to code, run, and debug Java programs from a single window. At the same time, JUnit is a unit testing library that will automatically test your Java code. You can write JUnit tests, and then you can run them automatically using Maven or Gradle plugin at build time. You can further automate your build using Jenkins, which means your Unit test will run continuously and automatically, reporting any break at the earlier possible opportunity.

How to add JAR files in Eclipse Project's Build path? Example

In this Java Eclipse tutorial, I will show you two ways to add external JAR files in Eclipse Java projects. Many times we need to use external JAR files in our Java application for different needs like for general purposes you may use Google Guava or Apache Commons. If you are using Spring or Hibernate framework then you need their JAR files as well. In order to use any third-party library or framework, we have to add their JAR files in the classpath, to compile and run our Java programs. Since Eclipse is the most popular IDE for developing Java applications, it's important to know how you can add external JARs into your Java project's build path. 

How to Increase Heap Size of Java Program running in Eclipse [Example]

It is possible to increase the heap size allocated by the JVM by using command-line options Here we have 3 options

-Xms<size>        to set the initial Java heap size
-Xmx<size>        to set the maximum Java heap size
-Xss<size>          to set the java thread stack size

$ java -Xms1G -Xmx2G MainClass

In the above line, we have set the minimum heap size to 1GB and the maximum heap size to 2GB.

How to Make Executable JAR file in Eclipse IDE - Java Example

If you are a Java programmer then you know what is the purpose of the JAR file, but for those who are unaware, the JAR file is deliverables of Java application. Just like C and C++ applications produce EXE files, Java produces JAR files. In other words, A JAR (Java Archive) file is a ZIP format file that bundles Java classes into a single unit, it may contain all the resources needed by Java application as well. There are mainly two types of the JAR file in Java:  Library JAR (normal JAR) files: JARs which are reusable libraries like Apache commons JAR file, guava.jar itself, or even JDBC drivers like ojdbc6_g.jar. There is another type as well, Executable JAR files: JARs which can be executed as standalone Java applications. 

How to deal with Unsupported major.minor version 55.0, 57,0, 60.0, 61.0 in Java + Eclipse + Linux [Solution]

The "unsupported major.minor version 55.0" error started to come after Java SE 11 release and the root cause of this error is trying to run a Java application compiled with JDK 11 into a JRE lower than Java SE 11 like JRE 9 or JRE 8. This is very common because a developer has updated their compiler or IDE to Java SE 11 but many times their runtime is not upgraded to Java 11. If you remember, in Java you can run a class file compiled with a lower version say Java 8 to a higher version say JRE 11 because Java is backward compatible but vice-versa is not allowed. I mean, you cannot run a JAR file or class file created by Java 11 version into  Java 8 or Java 9 version. Similarly, you cannot run a Java SE 17 compiled class file in Java SE 11 or Java SE 13 runtime environment.

3 ways to solve Eclipse - main class not found error

Like many Java programmers who get "Error: Could not find or load main class Main" while running the Java program in Eclipse, I was also getting the same problem recently. The "Error: Could not find or load main class" was rendered me puzzled even after my 10+ years of experience with Java errors and exceptions. Whenever I run my Java application either by Run configurations or right-click and run as a Java program, I get an annoying popup complaining about "could not find or load the main class, the program will exit". 

The Ultimate Guide of Remote Debugging in Java using Eclipse IDE? Example Tutorial

The remote debugging of the Java program is an ultimate tool in the arsenal of a Java developer, which is often becoming the last and only tool to investigate a bug on a Java application running on the remote host like on a Linux server or Windows server. Almost all major Java IDE provides remote debugging like NetBeans, Eclipse, and IntelliJ IDEA, but I mostly use Eclipse for Java coding and so it's my preferred tool to remote debug a Java program. In order to set up remote debugging in Eclipse, you need to do a couple of tasks like you need to start your JVM with debugging parameters or arguments and then you need to create a "remote debug configuration" in Eclipse IDE itself.

How to Attach Apache Tomcat Server in Eclipse for Running and Debugging Java Web Application - Steps

Hello Java programmers, If you are doing Java Web development in Eclipse, then you definitely would like to run and debug your Java application right from Eclipse. To do so, you need to add Apache Tomcat in the Eclipse version you are using, like Eclipse Kepler, Oxygen, Photon, or Luna. Eclipse comes in multiple flavors, like Eclipse IDE for Java Developers, which is suitable for developers doing core Java work, and Eclipse IDE for Java EE developers, which is for people doing enterprise Java work, like developing Servlet, JSP, and EJB based applications in Eclipse. In fact, the Java EE version of Eclipse is also one of the most downloaded software built with Java, so far, more than 1 million programmers have downloaded it.

How to Create Java Project with Maven in Eclipse - Step by Step Guide

If you are not using Maven for managing dependency and creating a build for your Java project, then you are definitely missing something. Being an ardent fan of ANT, I started with Maven quite late, but once I started, I haven't looked back. Maven makes it so easy to add new open-source JAR files, building and testing your project that you wouldn't look back. By the way, like all the things starting is difficult. I spent countless hours will creating my first Java project using Maven and Eclipse, but those were days with older Eclipse IDE. 

How to Fix "Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core” - Cause and Solution

This error comes in when you are trying to use the JSTL core tag library in your JSP page but the web container is not able to locate corresponding TLD files, also known as tag library descriptors. In order to use the custom tags in the JSP page, the first step is to import them using the @taglib directive and for that purpose, we provide a URI. Many JSP developer thinks this is the location where TLD files are stored but that's not true, this is actually the value, custom tab library developer has put in the URL field of tag library descriptor. This misunderstanding causes lots of trouble while solving "Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core”.

JDBC - How to connect Eclipse to Oracle Database - Step by Step Guide Example

Though I prefer Toad or Oracle SQL Developer tool to connect Oracle database, sometimes it's useful to directly connect Eclipse to Oracle using JDBC using its Data Source Explorer view. This means you can view data, run SQL queries to the Oracle database right from your Eclipse window. This will save a lot of time wasted during switching between Toad and Eclipse or Oracle SQL Developer and Eclipse. Eclipse also allows you to view the Execution plan in both text and Graphical mode, which you can use to troubleshoot the performance of your SQL queries.

How to Run External Program, Command Prompt, and Batch files from Eclipse Console ? Example Tips

Hello guys, have you ever thought about how much time a Java developer spends on Eclipse, IntelliJ IDEA, or his favorite IDE? I guess most of his time, isn't it would be great to do as much as work possible from Eclipse itself, without switching to another application. Since switching between applications or programs requires some time, which is generally gone waste, I like to use Eclipse as much as possible, starting from coding in Java, executing Java programs to exploring XML files, and now even running the batch command from Eclipse.