从零创建maven工程

1.在某目录下创建maven工程根目录，如：HelloStudy文件夹

2.在HelloStudy文件夹下创建maven核心文件pom.xml

3.编写pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.wqw.study</groupId>
<artifactId>hellosutdy</artifactId>
<packaging>jar</packaging>
<name>wqw hellostudy</name>
<version>1.0-SNAPSHOT</version>
</project>

modelVersion指定了当前pom的版本，对于maven3来说只能是4.0.0；

groupId指定了工程的归属，如某公司或某基金会；

artifactId指定了项目在组中的唯一ID；

packaging指定了项目的打包方式；

name指定了maven工程的名字，可以省略；

version指定了当前工程的版本号。

4.编写项目代码

maven项目的代码路径为src/main/java，在此路径下创建HelloStudy类

package com.wqw.study.hellostudy;

public class HelloStudy{

public static void main(String[] args){

System.out.println("hello study");

}

}

maven一般会自动扫描src/main/java文件夹下的包和代码，包路径应当与groupId、artifactId相符，如代码所示。

5.maven初次编译

在项目根部路下运行命令mvn clean compile

F:\Study\HelloStudy>mvn clean compile
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building wqw hellostudy 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ hellosutdy ---
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ hellosutdy
---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e
. build is platform dependent!
[INFO] skip non existing resourceDirectory F:\Study\HelloStudy\src\main\resource
s
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ hellosutdy ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. buil
d is platform dependent!
[INFO] Compiling 1 source file to F:\Study\HelloStudy\target\classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.262 s
[INFO] Finished at: 2016-04-11T16:02:16+08:00
[INFO] Final Memory: 14M/199M
[INFO] ------------------------------------------------------------------------

编译，clean是清理target目录，compile是进行编译。

6.编写测试代码

maven项目的测试代码路径为src/test/java，在此路径下创建HelloStudyTest类

package com.wqw.study.hellostudy;

public class HelloStudyTest{

@org.junit.Test
public void test(){

System.out.println("hello study test");

}

}

7.maven运行测试代码

在项目根部路下运行命令mvn clean test

F:\Study\HelloStudy>mvn clean test
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building wqw hellostudy 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ hellosutdy ---
[INFO] Deleting F:\Study\HelloStudy\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ hellosutdy
---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e
. build is platform dependent!
[INFO] skip non existing resourceDirectory F:\Study\HelloStudy\src\main\resource
s
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ hellosutdy ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. buil
d is platform dependent!
[INFO] Compiling 1 source file to F:\Study\HelloStudy\target\classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ he
llosutdy ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e
. build is platform dependent!
[INFO] skip non existing resourceDirectory F:\Study\HelloStudy\src\test\resource
s
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ hellosu
tdy ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. buil
d is platform dependent!
[INFO] Compiling 1 source file to F:\Study\HelloStudy\target\test-classes
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ hellosutdy ---
[INFO] Surefire report directory: F:\Study\HelloStudy\target\surefire-reports

-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running com.wqw.study.hellostudy.HelloStudyTest
hello study test
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.029 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.264 s
[INFO] Finished at: 2016-04-11T16:24:38+08:00
[INFO] Final Memory: 15M/166M

8.maven打包和运行

打包命令：mvn clean package

输出：hellosutdy-1.0-SNAPSHOT.jar

如何让其他项目可以引用此包：

install命令：mvn clean install

输出：在.m2文件夹下可以找到.m2\repository\com\wqw\study\helloworld文件夹

执行jar，默认打包的jar是不能够直接运行的，需要添加maven-shade-plugin插件进行编译，最终pom文件变为了：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.wqw.study</groupId>
<artifactId>hellosutdy</artifactId>
<packaging>jar</packaging>
<name>wqw hellostudy</name>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>1.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>com.wqw.study.hellostudy.HelloStudy</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

编译完成后执行jar：

java -jar hellosutdy-1.0-SNAPSHOT.jar

输出：hello study

本文结束。