This article shows how to decompile Java class in Eclipse IDE, IntelliJ IDEA, and command line. Table of contents 1. Java Decompilers 2. Decompile Java class in Eclipse IDE 3. Decompile Java class in IntelliJ IDEA 4. Decompile Java class in Command Line (FernFlower) 5. References 1. Java Decompilers Java decompiler can convert .class files […]
The Apache Maven Eclipse Plugin is retired, no more following commands # support eclipse ide $ mvn eclipse:eclipse # web project $ mvn eclipse:eclipse -Dwtpversion=2.0 What is the equivalent in Eclipse IDE? 1. Solution Please use Eclipse Maven Integration (m2e). Latest Eclipse IDE has bundled the m2e plugin : 2. How to use m2e? The […]
Maven compile a project in Eclipse IDE, but hits the following error messages : $ mvn clean compile [ERROR] COMPILATION ERROR : [INFO] ————————————————————- [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? [INFO] 1 error [INFO] ————————————————————- [INFO] ———————————————————————— [INFO] BUILD FAILURE [INFO] ———————————————————————— […]
For example, I want to know this SpringBootApplication class belongs to which JAR or dependency : import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class SpringBootWebApplication { public static void main(String[] args) throws Exception { SpringApplication.run(SpringBootWebApplication.class, args); } } Solution In Eclipse IDE, double clicks on the class name, press CTRL + SHIFT + T (win/*nix) or […]
In Eclipse, you press CTRL + SHIFT + O “Organize Imports” to import packages automatically. For IntelliJ IDEA, if you press CTRL + ALT + O “Optimize Imports”, it just removes some unused imports, never imports any package. And the worst is you need click on the class name and press ALT + ENTER keys […]
CTRL + H is IDEA equivalent of Eclipse show class hierarchy. Clicks on a class and press CTRL + H, it will display the subtypes hierarchy of the class. 1. Windows or & *nix = CTRL + H 2. Mac OSX Control + H References Show class hierarchy in Eclipse IDE
If you run or debug a web project in Eclipse, the project name will be the default context root. For example, a project named “springmvc”, the default context root will be http://localhost:8080/springmvc Technologies tested : Eclipse 4.4 Eclipse Tomcat server plugin Maven 3 Gradle 2.0 Note The context root tell you the URL of a […]
In this tutorial, we will show you how to change the Eclipse Theme. Tools used : Eclipse 4.4 Luna, works on earlier version. Eclipse Color Theme Plugin Figure : This is how your final Eclipse IDE looks like 1. Install Eclipse Color Theme Plugin Install the theme plugin and restart Eclipse. Eclipse menu -> Help […]
In Maven, you can get source code for project dependencies in most IDEs like this : $ mvn dependency:sources $ mvn dependency:resolve -Dclassifier=javadoc Get source code for Jar Get javadoc for Jar, normally, developers don’t provide this. 1. Eclipse IDE In Eclipse IDE, it’s better to use the maven eclipse plugin: $ mvn eclipse:eclipse -DdownloadSources=true […]
By default Eclipse deploys web application to a internal plugin folder called wtpwebapps, which is located in the following directory : {Your_Workspace}/.metadata/.plugins/org.eclipse.wst.server.core/tmp{number}/wtpwebapps #Example 1 – Windows C:\Users\mkyong\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps #Example 2 – Mac OSX /Users/mkyong/Documents/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps How it works In Server view, double clicks on the “Tomcat Server”, the deployment work is defined in the Server Locations To […]
In this tutorial, we will show you how to debug an Ant-Ivy web project in Eclipse IDE. Technologies used : Eclipse 4.2 Eclipse Tomcat Plugin Ant 1.9.4 Apache IvyDE Spring 4.1.3.RELEASE Note Previous Ant Spring MVC web project will be reused. 1. Install Apache IvyDE Install Apache IvyDE, it integrates Ivy into Eclipse IDE. Restart […]
In this tutorial, we will show you how to configure Eclipse debugger to support hot deploy, hot swap or hot code replace without restarting the Server, this speed development a lot. Environment : Eclipse 4.4 (Supported in older version as well) Eclipse Tomcat Plugin 1. Hot deploy example Review a simple hot deploy example, code […]
In Eclipse IDE, If a project contains errors, a small “red-x” icon will be displayed in the files that are causing the error. This useful feature is supported in Java related perspectives only, for example, “Package Explorer”. 1. Problem Personally, I prefer to use the “Project Explorer” perspective (pure folder structure), but the “red-x” icon […]
Here is the development environment Eclipse 4.3 Kepler Java 1.7 Spring 3.2, a MVC project using JSP view. 1. Problem Recently, Eclipse IDE is prompting following error message on top of all of the .tag file. The superclass "javax.servlet.jsp.tagext.SimpleTagSupport" was not found on the Java Build Path. See figure : P.S The SimpleTagSupport class is […]
In Eclipse IDE, run a Java web application with Tomcat server plugin, but the console prompts Exception in thread "x" java.lang.OutOfMemoryError: Java heap space 1. Solution – Increase Heap Size in Tomcat By default, Tomcat allocated a small amount of heap size. To solve it, you need to increase the Tomcat’s heap size manually. 1.1 […]
This article shows how to solve the java.lang.OutOfMemoryError: Java heap space in Eclipse IDE. Table of contents 1. Eclipse – OutOfMemoryError: Java heap space 2. Temporary fix – Increase the heap size 3. eclipse.ini 4. The solution, find the reason behind the heap size error. 5. References 1. Eclipse – OutOfMemoryError: Java heap space In […]
This article shows you how to attach the JDK source code in Eclipse IDE. In Eclipse, select Windows -> Preferences -> Java -> Installed JREs , expands rt.jar, select “Source attachment” and find the src.zip from your disk drive. P.S JDK source code is inside the src.zip. Note You may interest at this article – […]
Problem Downloaded a Java sample from Alexa API on Amazon service, imports it into Eclipse, but unable to compile and hits following “Access restriction” errors : Access restriction: The type BASE64Encoder is not accessible due to restriction on required library /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar P.S Using JDK 1.6 and Eclipse IDE 4.2 import sun.misc.BASE64Encoder; // Access restriction error […]
This tutorial shows you how to convert a Java project to Java web application project in Eclipse 4.2, it should work in older version as well. 1. Java Project A simple Java project. 2. Project Facets Right click on the project properties. Select “Project Facets“, and click “convert to faceted form…” Check “Dynamic Web Module” […]
By default, code assist in editing a pom.xml is NOT supported in Eclipse IDE. It make Maven project hard to maintain, and who will remember who all those tags? Solution You need a pom.xml Maven editor, which is available in m2eclipse plugin. In Eclipse, menu, select “Help” -> “Install New Software”, and put following m2eclipse […]
Still busy writing setters and getters method manually? Actually, Eclipse IDE is able to help you generate the setters and getters method automatically, and this feature is bundle with Eclipse IDE long time ago, surprisingly, many Java developers are not aware of it? See following steps to show you how. 1. Java Pojo A simple […]
In Eclipse, as long as your JSF + PrimeFaces project with JSF facet enabled, the PrimeFaces code completion is available automatically. Figure : PrimeFaces code assist in Eclipse IDE Tools Tested : JSF 2.1.11 Eclipse 4.2 PrimeFaces 3.3 Figure : Steps to enable JSF facet in Eclipse IDE. For detail instruction to configure JSF facet, […]
Problem Import a Java web project in Eclipse, build with Maven, once create a Tomcat server instance, unable to add the Java web project, and showing Tomcat version 6.0 only supports J2EE 1.2, 1.3, 1.4, and Java EE 5 Web modules Tools used : Eclipse Juno 4.2 Tomcat 6.0.35 JDK 1.6 Solution In project, “.settings” […]
Problem Forgot what i did, may be installed m2eclipse plguin, it made the M2_REPO classpath variable is unable to edit. Select Windows -> Preferences -> Java -> Build Path -> Classpath Variables. Eclipse come with embedded Maven and have this M2_REPO classpath variable default non modifiable also. Figure – M2_REPO is non modifiable Solution To […]
In this tutorial, we will show you how to use Eclipse to create a Google App Engine (GAE) Python web project (hello world example), run it locally, and deploy it to Google App Engine account. Tools used : Python 2.7 Eclipse 3.7 + PyDev plugin Google App Engine SDK for Python 1.6.4 P.S Assume Python […]
In this tutorial, we will show you how to use Eclipse to create a Google App Engine (GAE) Java project (hello world example), run it locally, and deploy it to Google App Engine account. Tools used : JDK 1.6 Eclipse 3.7 + Google Plugin for Eclipse Google App Engine Java SDK 1.6.3.1 Note GAE supports […]
Problem While installing Google Plugin for Eclipse 3.7, via http://dl.google.com/eclipse/plugin/3.7 , it took almost half and hour and download and stopped at the end. A long list of error messages “.jar has been tampered!” are prompted in Eclipse. An error occurred while collecting items to be installed session context was:(profile=epp.package.jee, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=). No repository […]
1. Problem While installing Google plugin for Eclipse, hit following weird error messages, and caused a long download time and stopped at the end. "Install download" has encountered a problem "Install download1" has encountered a problem "Install download2" has encountered a problem "Install download3" has encountered a problem "Install download4" has encountered a problem See […]
In Eclipse, to import a single class, you may clicked on the class and press shortcut key “Ctrl + Space” to prompt all the available classes to import. However, if you copied a Java source code from somewhere and more than 20+ classes are not import, are you going to press “Ctrl + Space” one […]
Often times, after code refactor or bug fixed, Eclipse IDE will show a yellow underline for all unsed imports at the top of your class and said “The import xxx is never used“. To remove those unused imports automatically, just click on the class and press the shortcut “Ctrl + Shift + O” to initilize […]
By default, Eclipse’s editor will not display line numbers, it’s no good for debugging. Here’s a tip to show you how to turn on the “display line numbers” feature in Eclipse. In Eclipse IDE, select “Windows” > “Preference” > “General” > “Editors” > “Text Editors” , check on the “Show line numbers” option. See result.
By default, Android SDK or Eclipse ADT plugin are not bundle with any Android’s source code for debugging. In Eclipse IDE, step into any Android class will prompt no source code attach, see following screen : Solution According to this official Android source code article, it’s shocked that we need to use “repo” to download […]
During Eclipse development, it’s not practical to go outside of the Eclipse’s environment and execute Maven command in external console. In this article, we show you how to integrate Maven command with Eclipse IDE, via Eclipse’s “External Tool Configuration“. Normally, this external tool is used to run external command within Eclipse environment, and it works […]
In last tutorial, you created a Java project with Maven, but that project is not able to import into Eclipse IDE, because it is not Eclipse style project. Here’s a guide to show you how to convert the Maven generated Java project to Eclipse supported style project. 1. mvn eclipse:eclipse It’s really easy to do […]
Eclipse IDE has build-in integration with Concurrent Versions System (CVS), but not Subversion (SVN). Here’s a guide to show you how to make Eclipse IDE support Subversion (SVN) via Subclipse plugin. 1. Subclipse Plugin Visit this link : http://subclipse.tigris.org/ , click on the “Download and Install” tab. Get the “Eclipse update site URL” for Subclipse […]
So far, there is still lack of WebSphere 7 plugin for both Eclipse and NetBeans IDE. However, you are able to debug your web application via Java Debugger (jdb). Here’s a guide to show you how to remote debugging your web application in Eclipse and WebSphere via Java Debugger (jdb). Eclipse <—-> Java Debugger (jdb) […]
In SOAP web service, each HTTP request or response encapsulates a SOAP envelope, these messages are easy to trace by using Eclipse IDE, build-in “TCP/IP monitor” tool. The idea is host another server in between the client and server to perform port forward function to intercept the HTTP traffic. 1. Normal SOAP envelope flows In […]
In Eclipse Ganymede (v3.4) or Galileo (v3.5), it supports until JSF 1.2 only. For JSF 2.0, upgrade your Eclipse to version Helios (v3.6) onward, it has full support of Java EE 6 support, including JSF 2.0. Here’s a quick guide to show you how to enable JSF 2.0 features like code assist and visual JSF […]
Problem Using Eclipse Helios (3.6) and developing JSF 2.0 web application. In .xhtml file, when i pressed on the “Ctrl + Space” combination keys to call the code assist for JSF tag, it prompts nothing? It look like the code assist for JSF tag is not working properly in the .xhtml file extension? Solution In […]
Problem In Eclipse 3.5 or early version, in order to deployed the Maven dependencies to the correct “/WEB-INF/lib” folder, you have to configure the dependencies via “Java EE Module Dependencies”, and the updated “.classpath” file will look like following : File : “.classpath”, by Java EE Module Dependencies… … <classpathentry kind="var" path="M2_REPO/javax/servlet/jsp/jsp-api/2.1/jsp-api-2.1.jar" sourcepath="M2_REPO/javax/servlet/jsp/jsp-api/2.1/jsp-api-2.1-sources.jar"> <attributes> <attribute […]
