Maven 打包实战

前言

上一章,我们介绍了Maven内的常见插件.Maven的主要作用是用于包的管理和依赖.其次,根据Maven的生命周期可以知道, 它还可以作为一个运维和打包、部署的工具而存在.

本章我们将详细的介绍Maven打包以及打包的各种情况.

PS: 本文所用的Maven例子可以在我的Github仓库内找到
https://github.com/SeanYanxml/maven-train

---

Jar包

所谓Jar包,其实就是Java文件的压缩包.我们在整理文件的时候,经常会将其压缩为.rar / .zip / .tar / .tar.gz等待诸如此类的压缩包.其实Jar包也不例外,它其实就是用于Java程序进行压缩发布的一种格式包.

• Eclipse打包
  经常使用Eclipse的朋友们肯定会知道,Eclipse自带了Export功能,可以将项目导出为Jar包
  
  如果发布工具包的话,可以选择JAR file.但是,如果想要发布应用程序,也就是可运行Jar包的话,我们一般选择Runnable JAR file.

我们选择可运行Jar包,可以看到下方的几种选项:

• 刨除需要的其他非项目内的Jar包;
• 将需要的Jar包一起打包;
• 拷贝需要的Jar包一起(一般是. tar.gz)
  
  我们分别试验和查看下这2种方式的区别:

localhost:Desktop Sean$ java -jar hello1.jar
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
String is not null.
localhost:Desktop Sean$ java -jar hello2.jar
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
String is not null.
localhost:Desktop Sean$ java -jar hello3.jar
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
String is not null.

从试验的结果来看,三种Jar包都可以运行.下面我们通过反编译jd-gui.jar程序依次查看下我们打的三种包的不同

• 第一种 压成一个Jar包
  可以看到,所有的程序.包括依赖的common-lang3.jar内的所有内容,包括Maven的pom.xml文件都被压在了一起.
  这种做法适合,小型工具类发布,依赖的Jar包较少切Jar包冲突较少的情况.

• 第二种 Jar包内包含Jar包
  
  由上图可以看到,我们hello2.jarJar包内还包含了Jar包.并且,Manifest.mf文件要加载common-lang.jarjar包

• 第三种 依赖Jar包另外存储
  
  这种方法适用于,迭代发布时,Jar包经常会出现冲突的问题.但是这个的依赖位置基本上不能够更改.

有时,我们可以手动的去加载这些我们需要的Jar包到运行的classpath目录下.学习下zookeeper的Jar包加载脚本

#!/bin/bash
for i in ./lib/*.jar
do
    CLASSPATH="$i:$CLASSPATH"
done

MainJar="hello3.jar" 
MainClass="com.yanxml.parent.son.HelloMain"
CLASSPATH="$MainJar:$CLASSPATH"


echo "$CLASSPATH"
java -cp "$CLASSPATH" "$MainClass"

java -cp ./lib/commons-lang3-3.7.jar:hello3.jar com.yanxml.parent.son.HelloMain

---

Maven 插件

相比较而言,前文介绍的插件中

• maven-shade-plugin类比第一种插件打包方式
• maven-source-plugin 打源码包
• maven-dependency-plugin类比第三种打包方式
• spring-boot-maven-plugin类比第二种打包方式,但是根据SpringBoot的需求又进行了一定的封装.

当然,我们自动化的过程中是不能用界面进行操作的,于是本章节.我们将使用maven对于这3种方式进行实现.
(注:第二种打包方式略微特殊,需要第三方的启动类,我们举一个使用SpringBoot插件的例子进行替换.(使用FatJar可以实现这样的效果))

• 合并打包(maven-shade-plugin)

#pom.xml

	4.0.0
	
		com.yanxml
		maven-train-parent
		0.0.1-SNAPSHOT
	
	maven-train-parent-son

	
		
		
			com.yanxml
			maven-train-parent-util
			0.0.1-SNAPSHOT
		

	

	
		
			
			
				org.apache.maven.plugins
				maven-shade-plugin
				2.4.3
				
					
						package
						
							shade
						
						
							
								
									
										com.yanxml.parent.son.HelloMain
										1.7
										1.7
									
								
							
						
					
				
			
			
			
		
	

注意 因为此父项目的子项目,所以需要在父亲路径运行mvn clean package -pl maven-train-parent-son -am命令进行打包.打包时可以选择是否将依赖模块重新打包.

localhost:maven-train-parent Sean$ pwd
/Users/Sean/Documents/Gitrep/maven-train/maven-train-parent
localhost:maven-train-parent Sean$ mvn clean package -pl maven-train-parent-son -am
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] maven-train-parent
[INFO] maven-train-parent-util
[INFO] maven-train-parent-son
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven-train-parent 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-train-parent ---
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven-train-parent-util 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-train-parent-util ---
[INFO] Deleting /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-util/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-train-parent-util ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-train-parent-util ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-util/target/classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ maven-train-parent-util ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ maven-train-parent-util ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ maven-train-parent-util ---
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ maven-train-parent-util ---
[INFO] Building jar: /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-util/target/maven-train-parent-util-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven-train-parent-son 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-train-parent-son ---
[INFO] Deleting /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-train-parent-son ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-train-parent-son ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/target/classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ maven-train-parent-son ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ maven-train-parent-son ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ maven-train-parent-son ---
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ maven-train-parent-son ---
[INFO] Building jar: /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/target/maven-train-parent-son-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- maven-shade-plugin:2.4.3:shade (default) @ maven-train-parent-son ---
[INFO] Including com.yanxml:maven-train-parent-util:jar:0.0.1-SNAPSHOT in the shaded jar.
[INFO] Including org.apache.commons:commons-lang3:jar:3.7 in the shaded jar.
[INFO] Replacing original artifact with shaded artifact.
[INFO] Replacing /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/target/maven-train-parent-son-0.0.1-SNAPSHOT.jar with /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/target/maven-train-parent-son-0.0.1-SNAPSHOT-shaded.jar
[INFO] Dependency-reduced POM written at: /Users/Sean/Documents/Gitrep/maven-train/maven-train-parent/maven-train-parent-son/dependency-reduced-pom.xml
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] maven-train-parent ................................. SUCCESS [  0.223 s]
[INFO] maven-train-parent-util ............................ SUCCESS [  1.968 s]
[INFO] maven-train-parent-son ............................. SUCCESS [  0.671 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.994 s
[INFO] Finished at: 2019-03-13T18:36:12+08:00
[INFO] Final Memory: 20M/172M
[INFO] ------------------------------------------------------------------------

包运行完成后,会放置在/target子目录内.反编译后,可以看到,和Eclipse打包基本一致.

• 运行包与依赖包分开打包(maven-dependency-plugin)

	4.0.0
	
		com.yanxml
		maven-train-parent
		0.0.1-SNAPSHOT
	
	maven-train-parent-son

	
		
		
			com.yanxml
			maven-train-parent-util
			0.0.1-SNAPSHOT
		

	

	
		

	
		org.apache.maven.plugins
		maven-dependency-plugin
		2.10
		
			
				copy-dependencies
				package
				
					copy-dependencies
				
				
					./lib
				
			
		
	
			
			
		
	

由上可以看到,我们将源码打入一个包内.所有依赖的包都放置在配置的指定目录下.
但是,我们运行时候,需要特定的脚本将其加载进入classpath下.

• Jar In Jar(spring-boot-maven-plugin)
  在本教程的Github上,我们有一个现成的SpringBoot项目.下面两节,我们使用这个项目,完成下面两节.

#pom.xml

localhost:maven-train-springboot Sean$ mvn package
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.yanxml:maven-train-springboot:jar:1.0
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin is missing. @ line 55, column 12
[WARNING] 'build.plugins.plugin.version' for org.springframework.boot:spring-boot-maven-plugin is missing. @ line 63, column 12
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven-train-springboot 1.0
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for org.apache.logging.log4j:log4j-core:jar:2.7 is invalid, transitive dependencies (if any) will not be available, enable debug logging for more details
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-train-springboot ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 2 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven-train-springboot ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ maven-train-springboot ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/Sean/Documents/Gitrep/maven-train/maven-train-springboot/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ maven-train-springboot ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ maven-train-springboot ---
[INFO]
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ maven-train-springboot ---
[INFO] Building jar: /Users/Sean/Documents/Gitrep/maven-train/maven-train-springboot/target/maven-train-springboot-1.0.jar
[INFO] META-INF/maven/com.yanxml/maven-train-springboot/pom.xml already added, skipping
[INFO] META-INF/maven/com.yanxml/maven-train-springboot/pom.properties already added, skipping
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.9.RELEASE:repackage (default) @ maven-train-springboot ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.967 s
[INFO] Finished at: 2019-03-13T19:02:21+08:00
[INFO] Final Memory: 17M/226M
[INFO] ------------------------------------------------------------------------

(依赖的Jar包都放在lib文件夹内)通过java -jar maven-train-springboot-1.0.jar可以将其进行启动.

• 自定义打包(maven-assembly-plugin)

### assembly.xml

  
    0.1
    
        tar
    
      
    
        
        
            target/classes
            /config
            0755
            
              *.properties
              *.xml
              banner.txt
              *.json
            
        
        
        
            target/classes/bin
            /config/bin
            0755
        
        
        
            target/lib
            /lib
            0755
        
        
    
    
     
		
			target/${package}-1.0.jar
			/
			${package}-${package.version}.jar
			0755
		
	 
    
    
   

				maven-assembly-plugin
				
					${package}-${package.version}
					true
					false
					
						src/main/assembly/${package.format}-assembly.xml
					
				
				
			

tar包内的情况如下所示:

localhost:target Sean$ tar -xvf maven-train-springboot-v1.tar
x maven-train-springboot-v1/maven-train-springboot-v1.jar
x maven-train-springboot-v1/config/application.properties
x maven-train-springboot-v1/config/log4j2.xml

---

Reference

[1]. Maven 常见插件
[2]. java cp命令
[3]. Maven的-pl -am -amd参数学习
[4]. Maven deploy跳过某个module解决办法
[5]. maven 单独构建多模块项目中的单个模块