SpringBoot項目使用Maven打包:
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
執行mvn clean package命令後,生成應用jar,用壓縮文件查看,maven自動生成了MANIFEST.MF文件:
Manifest-Version: 1.0
Implementation-Title: github-demo
Implementation-Version: 2.1-SNAPSHOT
Start-Class: com.gitlab.example.demo.DemoApplication
Spring-Boot-Classes: BOOT-INF/classes/
Spring-Boot-Lib: BOOT-INF/lib/
Build-Jdk-Spec: 1.8
Spring-Boot-Version: 2.2.1.RELEASE
Created-By: Maven Archiver 3.4.0
Main-Class: org.springframework.boot.loader.JarLauncher
依賴的jar也在應用jar 中,位於BOOT-INF/lib/目錄下。使用java -jar 即可運行這個應用jar包。
爲了提高部署的效率,需要把應用jar包跟依賴jar包分開,當項目中沒有新增依賴的jar包時,只需把應用單獨打包出來就行,這樣應用jar包的大小會小很多。
這需要maven-jar-plugin插件,改變默認的打包方式;還需要maven-dependency-plugin,把依賴的jar包打包。pom文件主要部分如下:
<build>
<plugins>
<!--設置應用 Main 參數啓動依賴查找的地址指向外部 lib 文件夾-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<!-- 項目所依賴的jar位於同一級的lib目錄下-->
<classpathPrefix>lib/</classpathPrefix>
</manifest>
</archive>
</configuration>
</plugin>
<!--設置 SpringBoot 打包插件不包含任何 Jar 依賴包-->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<includes>
<include>
<groupId>nothing</groupId>
<artifactId>nothing</artifactId>
</include>
</includes>
</configuration>
</plugin>
<!--設置將 lib 拷貝到應用 Jar 外面-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
目的就是爲了把依賴的jar包放到target/lib目錄下,在MANIFEST.MF文件中自動添加Class-Path屬性,指向所依賴的jar包:
Manifest-Version: 1.0
Implementation-Title: github-demo
Implementation-Version: 2.4-SNAPSHOT
Start-Class: com.gitlab.example.demo.DemoApplication
Spring-Boot-Classes: BOOT-INF/classes/
Class-Path: lib/spring-boot-starter-web-2.2.1.RELEASE.jar lib/spring-b
oot-starter-2.2.1.RELEASE.jar lib/spring-boot-2.2.1.RELEASE.jar lib/s
pring-boot-autoconfigure-2.2.1.RELEASE.jar lib/spring-boot-starter-lo
gging-2.2.1.RELEASE.jar lib/logback-classic-1.2.3.jar lib/logback-cor
e-1.2.3.jar lib/log4j-to-slf4j-2.12.1.jar lib/log4j-api-2.12.1.jar li
b/jul-to-slf4j-1.7.29.jar lib/jakarta.annotation-api-1.3.5.jar lib/sn
akeyaml-1.25.jar lib/spring-boot-starter-json-2.2.1.RELEASE.jar lib/j
ackson-databind-2.10.0.jar lib/jackson-annotations-2.10.0.jar lib/jac
kson-core-2.10.0.jar lib/jackson-datatype-jdk8-2.10.0.jar lib/jackson
-datatype-jsr310-2.10.0.jar lib/jackson-module-parameter-names-2.10.0
.jar lib/spring-boot-starter-tomcat-2.2.1.RELEASE.jar lib/tomcat-embe
d-core-9.0.27.jar lib/tomcat-embed-el-9.0.27.jar lib/tomcat-embed-web
socket-9.0.27.jar lib/spring-boot-starter-validation-2.2.1.RELEASE.ja
r lib/jakarta.validation-api-2.0.1.jar lib/hibernate-validator-6.0.18
.Final.jar lib/jboss-logging-3.4.1.Final.jar lib/classmate-1.5.1.jar
lib/spring-web-5.2.1.RELEASE.jar lib/spring-beans-5.2.1.RELEASE.jar l
ib/spring-webmvc-5.2.1.RELEASE.jar lib/spring-aop-5.2.1.RELEASE.jar l
ib/spring-context-5.2.1.RELEASE.jar lib/spring-expression-5.2.1.RELEA
SE.jar lib/slf4j-api-1.7.29.jar lib/spring-core-5.2.1.RELEASE.jar lib
/spring-jcl-5.2.1.RELEASE.jar
Spring-Boot-Lib: BOOT-INF/lib/
Build-Jdk-Spec: 1.8
Spring-Boot-Version: 2.2.1.RELEASE
Created-By: Maven Archiver 3.4.0
Main-Class: org.springframework.boot.loader.JarLauncher
這樣,當打出來的應用jar包,跟依賴jar包的lib文件夾放在同一個目錄下時,使用java -jar就可以運行應用jar包了。