If you just start to develop some application, you need some built tools to help to package, compile or make your development structure look right.
Maven is a right tool for that. It’s simple and easy to use, it works with many of programming languages, especially with Java.
Here is simple steps to install maven in your Windows:
Download & Set Environment Variables
- Download maven 2 (version 3.0.4)
- You need to have JVM installed in your PC
- Extract the tar.gz and put in some folder (Ex: D:\install\apache-maven-3.0.4)
- Configure Environment Variable:
- Right Click on My Computer > Properties > Advanced > Environment Variables
- Create New System Variables: M2_HOME & maven memory option as
- M2_HOME=D:\install\apache-maven-3.0.4
- MAVEN_OPTS=-Xms256m -Xmx512m
- Set path of M2_HOME: path=%M2_HOME%\bin;%path%
Prepare Your home folder
- Go to your home directory (C:\Documents and Settings\[your PC user]
- Create following folders (.m2 & .m2/repository) via DOS prompt:
C:\DOCUME~1\[your-user]>mkdir .m2 C:\DOCUME~1\[your-user]>cd .m2 C:\DOCUME~1\[your-user]\.m2>mkdir repository
File: settings.xml
This file is useful for maven to collect all common configuration values that we can do in pom.xml as well. In settings.xml file should not contain specific configuration for some projects but generic for all.
There are two locations where a settings.xml file may live:
- The Maven install: $M2_HOME/conf/settings.xml
- A user’s install: ${user.home}/.m2/settings.xml
I think, you can just use the simple configuration below and put it in ${user.home}/.m2/settings.xml
<?xml version="1.0" encoding="UTF-8"?> <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd"> <localRepository>${user.home}/.m2/repository</localRepository> <interactiveMode>true</interactiveMode> <usePluginRegistry>false</usePluginRegistry> <offline>false</offline> </settings>
Testing & Maven Commands
Open DOS prompt and test command: mvn -version
D:\Work\develop\opensource>mvn -version Apache Maven 3.0.4 (r1232337; 2012-01-17 15:44:56+0700) Maven home: D:\install\apache-maven-3.0.4 Java version: 1.6.0_25, vendor: Sun Microsystems Inc. Java home: D:\install\java\jdk1.6.0_25\jre Default locale: en_US, platform encoding: Cp1252 OS name: "windows xp", version: "5.1", arch: "x86", family: "windows"
Some commands:
- Build project:
mvn package / mvn install
- Clean project:
mvn clean
- Build eclipse classpath:
mvn eclipse:eclipse
- Clean eclipse classpath:
mvn eclipse:clean
Common Mistakes
1. When build got error: java.lang.ClassNotFoundException: org.codehaus.classworlds.Launcher
Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/classworlds/La Caused by: java.lang.ClassNotFoundException: org.codehaus.classworlds.Launcher at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) Could not find the main class: org.codehaus.classworlds.Launcher. Program will exit.
Issue & Resolution:
- Set environment variable, make sure that no conflict variable between: M2_HOME or M3_HOME; Only one should be used, my case I used: M2_HOME only.
- JDK to use 1.6 or latest for maven 3.04