使用Maven打包你的應用——maven-jar-plugin & maven-assembly-plugin & maven-shade-plugin
阿新 • • 發佈：2018-12-15
介紹
maven-jar-plugin，maven-assembly-plugin和maven-shade-plugin的使用，和他們之間的區別。原文出自:https://blog.dubby.cn/detail.html?id=9091
1.maven-jar-plugin
首先，需要配置這個plugin:
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <classpathPrefix>lib/</classpathPrefix> <mainClass>cn.dubby.maven.jar.plugin.Main</mainClass> </manifest> </archive> </configuration> </plugin>
編寫啟動類:
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);
}
啟動:
➜ target git:(master) ✗ java -jar maven-jar-plugin-1.0-SNAPSHOT.jar Hello, this is a application packaged by maven-jar-plugin
但是，如果加上一個依賴呢？
我們加上joda-time的依賴:
<dependencies> <!-- https://mvnrepository.com/artifact/joda-time/joda-time --> <dependency> <groupId>joda-time</groupId> <artifactId>joda-time</artifactId> <version>2.9.9</version> </dependency> </dependencies>
修改啟動類:
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);
}
再執行:
➜ 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
發現我們增加的依賴並沒有找到，怎麼辦呢？
請注意觀察我們上面配置maven-jar-plugin時的另外兩個配置項:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>cn.dubby.maven.jar.plugin.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
addClasspath和classpathPrefix表明會把lib下的jar作為第三方依賴加入package裡，所以我們需要把依賴拷貝到lib目錄下，我們可以使用maven-dependency-plugin:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy</id>
<phase>compile</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>
${project.build.directory}/lib
</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
這樣我們重新打包再執行:
➜ 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目錄下也可以發現多了個lib目錄。
2.maven-assembly-plugin
先配置plugin:
<!-- Maven Assembly Plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4.1</version>
<configuration>
<!-- get all project dependencies -->
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<!-- MainClass in mainfest make a executable jar -->
<archive>
<manifest>
<mainClass>cn.dubby.maven.assembly.plugin.Main</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<!-- bind to the packaging phase -->
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
啟動類同上:
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);
}
打包執行結果:
➜ 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
3.maven-shade-plugin
配置如下:
<!-- maven-shade-plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.1.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>cn.dubby.maven.shade.plugin.Main</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
啟動類同上:
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);
}
結果:
➜ 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
4.package比較
-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