三种打包插件
| plugin | function |
|---|---|
| maven-jar-plugin | maven 默认打包插件，用来创建 project jar |
| maven-shade-plugin | 用来打可执行包，executable(fat) jar |
| maven-assembly-plugin | 支持定制化打包方式，例如 apache 项目的打包方式 |
maven-jar-plugin
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.example.demo.Test</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.10</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
maven-jar-plugin用于生成META-INF/MANIFEST.MF文件的部分内容，
## MANIFEST.MF文件
Manifest-Version: 1.0
Implementation-Title: demo
Implementation-Version: 0.0.1-SNAPSHOT
Archiver-Version: Plexus Archiver
Built-By: zhangchengkang
Implementation-Vendor-Id: com.example
Class-Path: lib/spring-boot-starter-2.3.0.RELEASE.jar lib/spring-boot-
2.3.0.RELEASE.jar lib/spring-context-5.2.6.RELEASE.jar lib/spring-aop
-5.2.6.RELEASE.jar lib/spring-beans-5.2.6.RELEASE.jar lib/spring-expr
ession-5.2.6.RELEASE.jar lib/spring-boot-autoconfigure-2.3.0.RELEASE.
jar lib/spring-boot-starter-logging-2.3.0.RELEASE.jar lib/logback-cla
ssic-1.2.3.jar lib/logback-core-1.2.3.jar lib/slf4j-api-1.7.30.jar li
b/log4j-to-slf4j-2.13.2.jar lib/log4j-api-2.13.2.jar lib/jul-to-slf4j
-1.7.30.jar lib/jakarta.annotation-api-1.3.5.jar lib/spring-core-5.2.
6.RELEASE.jar lib/spring-jcl-5.2.6.RELEASE.jar lib/snakeyaml-1.26.jar
lib/fastjson-1.2.60.jar lib/jedis-2.9.0.jar lib/commons-pool2-2.8.0.
jar
Created-By: Apache Maven 3.6.3
Build-Jdk: 1.8.0_73
Implementation-Vendor: Pivotal Software, Inc.
Main-Class: com.example.demo.Test
maven-dependency-plugin插件用于将依赖包拷贝到
指定了Main-Class，有了依赖包，那么就可以直接通过java -jar xxx.jar运行jar包。
这种方式生成jar包有个缺点，就是生成的jar包太多不便于管理，下面两种方式只生成一个jar文件，包含项目本身的代码、资源以及所有的依赖包。
maven-shade-plugin
org.apache.maven.plugins
maven-shade-plugin
2.4.3
package
shade
com.example.demo.Test
这个jar文件是可以直接运行的
springBoot项目不能用此方法打包?
maven-assembly-plugin
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<id>make-assembly</id>
<!-- 绑定到package生命周期 -->
<phase>package</phase>
<goals>
<!-- 只运行一次 -->
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<!-- 配置描述符文件
<descriptors>src/main/assembly/assembly.xml</descriptors>-->
<!-- 也可以使用Maven预配置的描述符-->
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<!--删除后缀-->
<appendAssemblyId>false</appendAssemblyId>
<!--修改jar名称
<finalName>yourName</finalName>-->
</configuration>
</plugin>
</plugins>
</build>
####
可自定义配置描述符文件:
<?xml version='1.0' encoding='UTF-8'?>
<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0
http://maven.apache.org/xsd/assembly-1.1.0.xsd">
<id>demo</id>
<formats>
<format>jar</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<fileSets>
<fileSet>
<directory>${project.build.directory}/classes</directory>
<outputDirectory>/</outputDirectory>
</fileSet>
</fileSets>
</assembly>
- format：指定打包类型；
- includeBaseDirectory：指定是否包含打包层目录（比如finalName是output，当值为true，所有文件被放在output目录下，否则直接放在包的根目录下）；
- fileSets：指定要包含的文件集，可以定义多个fileSet；
- directory：指定要包含的目录；
- outputDirectory：指定当前要包含的目录的目的地。
spring-boot-maven-plugin
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
## MANIFEST.MF文件
Manifest-Version: 1.0
Spring-Boot-Classpath-Index: BOOT-INF/classpath.idx
Implementation-Title: demo
Implementation-Version: 0.0.1-SNAPSHOT
Start-Class: com.example.demo.DemoApplication
Spring-Boot-Classes: BOOT-INF/classes/
Spring-Boot-Lib: BOOT-INF/lib/
Build-Jdk-Spec: 1.8
Spring-Boot-Version: 2.3.0.RELEASE
Created-By: Maven Jar Plugin 3.2.0
Implementation-Vendor: Pivotal Software, Inc.
Main-Class: org.springframework.boot.loader.JarLauncher
spring-boot-maven-plugin所做的工作是在默认的maven-jar-plugin插件打包结束后，将项目依赖的jar包中的.class文件重新进行打包。
[INFO] --- maven-jar-plugin:3.2.0:jar (default-jar) @ demo ---
[INFO] Building jar: G:\project\package_demo\target\demo-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.3.0.RELEASE:repackage (repackage) @ demo ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- maven-install-plugin:2.5.2:install (default-install) @ demo ---
[INFO] Installing G:\project\package_demo\target\demo-0.0.1-SNAPSHOT.jar to C:\Users\zhangchengkang\.m2\repository\com\example\demo\0.0.1-SNAPSHOT\demo-0.0.1-SNAPSHOT.jar
[INFO] Installing G:\project\package_demo\pom.xml to C:\Users\zhangchengkang\.m2\repository\com\example\demo\0.0.1-SNAPSHOT\demo-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.208 s
[INFO] Finished at: 2020-05-20T11:29:19+08:00
[INFO] ------------------------------------------------------------------------
可以看出，在调用maven-jar-plugin的goal:jar任务打包之后，又调用了spring-boot-maven-plugin的goal:repackage任务，这样会产生两个jar包。
一个是demo-0.0.1-SNAPSHOT.jar(spring-boot-maven-plugin重新打包生成的可执行jar包)
另一个demo-0.0.1-SNAPSHOT.jar.original(maven-jar-plugin打包生成的jar包)
可以打开demo-0.0.1-SNAPSHOT.jar.original瞅瞅
巧不巧,跟maven-jar-plugin结构一毛一样
最后看看demo-0.0.1-SNAPSHOT.jar结构
