使用Maven打包你的应用——mavenjarplugin&mavenassemblyplugin&mavenshadeplugin

原文链接：https://www.dubby.cn/detail.html?id=9091

介绍maven-jar-plugin，maven-assembly-plugin和maven-shade-plugin的使用，和他们之间的区别。原文出自:https://blog.dubby.cn/detail.html?id=9091

1.maven-jar-plugin

首先，需要配置这个plugin:


org.apache.maven.plugins
maven-jar-plugin



true
lib/
cn.dubby.maven.jar.plugin.Main






编写启动类:

public static void main(String[] args) {
System.out.println("Hello, this is a application packaged by maven-jar-plugin");
LocalDateTime localDateTime = new LocalDateTime();
System.out.println(localDateTime);
}


启动:

➜ target git:(master) ✗ java -jar maven-jar-plugin-1.0-SNAPSHOT.jar
Hello, this is a application packaged by maven-jar-plugin


但是，如果加上一个依赖呢？

我们加上joda-time的依赖:




joda-time
joda-time
2.9.9




修改启动类:

public static void main(String[] args) {
System.out.println("Hello, this is a application packaged by maven-jar-plugin");
LocalDateTime localDateTime = new LocalDateTime();
System.out.println(localDateTime);
}


再运行:

➜ target git:(master) ✗ java -jar maven-jar-plugin-1.0-SNAPSHOT.jar
Hello, this is a application packaged by maven-jar-plugin
Exception in thread "main" java.lang.NoClassDefFoundError: org/joda/time/LocalDateTime
at cn.dubby.maven.jar.plugin.Main.main(Main.java:13)
Caused by: java.lang.ClassNotFoundException: org.joda.time.LocalDateTime
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 1 more


发现我们增加的依赖并没有找到，怎么办呢？

请注意观察我们上面配置maven-jar-plugin时的另外两个配置项:


org.apache.maven.plugins
maven-jar-plugin



true
lib/
cn.dubby.maven.jar.plugin.Main






addClasspath和classpathPrefix表明会把lib下的jar作为第三方依赖加入package里，所以我们需要把依赖拷贝到lib目录下，我们可以使用maven-dependency-plugin:


org.apache.maven.plugins
maven-dependency-plugin


copy
compile

copy-dependencies



${project.build.directory}/lib







这样我们重新打包再运行:

➜ target git:(master) ✗ java -jar maven-jar-plugin-1.0-SNAPSHOT.jar
Hello, this is a application packaged by maven-jar-plugin
2018-01-22T14:48:00.915


去target目录下也可以发现多了个lib目录。

原文出自:https://blog.dubby.cn/detail.html?id=9091

2.maven-assembly-plugin

先配置plugin:



org.apache.maven.plugins
maven-assembly-plugin
2.4.1



jar-with-dependencies




cn.dubby.maven.assembly.plugin.Main





make-assembly

package

single






启动类同上:

public static void main(String[] args) {
System.out.println("Hello, this is a application packaged by maven-assembly-plugin");
LocalDateTime localDateTime = new LocalDateTime();
System.out.println(localDateTime);
}


打包运行结果:

➜ target git:(master) ✗ java -jar maven-assembly-plugin-1.0-SNAPSHOT-jar-with-dependencies.jar
Hello, this is a application packaged by maven-assembly-plugin
2018-01-22T15:44:05.166


原文出自:https://blog.dubby.cn/detail.html?id=9091

3.maven-shade-plugin

配置如下:



org.apache.maven.plugins
maven-shade-plugin
3.1.0


package

shade




cn.dubby.maven.shade.plugin.Main








启动类同上:

public static void main(String[] args) {
System.out.println("Hello, this is a application packaged by maven-shade-plugin");
LocalDateTime localDateTime = new LocalDateTime();
System.out.println(localDateTime);
}


结果:

➜ target git:(master) ✗ java -jar maven-shade-plugin-1.0-SNAPSHOT.jar
Hello, this is a application packaged by maven-shade-plugin
2018-01-22T15:42:19.662


原文出自:https://blog.dubby.cn/detail.html?id=9091

4.package比较

-rw-r--r-- 1 teeyoung staff 622K 1 22 15:43 maven-assembly-plugin-1.0-SNAPSHOT-jar-with-dependencies.jar
-rw-r--r-- 1 teeyoung staff 3.1K 1 22 14:47 maven-jar-plugin-1.0-SNAPSHOT.jar
-rw-r--r-- 1 teeyoung staff 622K 1 22 15:42 maven-shade-plugin-1.0-SNAPSHOT.jar