maven(3)maven3.3.9使用入门
【0】README
1）maven 安装
step1）检查 jdk 是否安装且 环境变量 JAVA_HOME 是否设置；step2）download maven： https://maven.apache.org/download.cgi?Preferred=ftp://mirror.reverse.net/pub/apache/step3）解压，同样添加maven的环境变量M2_HOME（maven_home/bin 所在目录）；step4）mvn -n 测试 maven 安装是否正确；
2）相关概念补充（Supplement）
s1）构建：我们每天有相当一部分时间花在了编译，运行单元测试，生成文档，打包和部署等繁琐且不起眼的工作上，这叫做构建；s2）maven 通过一个坐标系统准确地定位每一个构建（jar文件）：也就是通过一组坐标 maven 能够找到任何一个 java 类库（如jar文件）；（干货——引入了坐标+定位）
3）maven的中央仓库和本地仓库
3.1）中央仓库：maven 为全球的 java 开发者提供了一个免费的中央仓库（http://repo1.maven.org/maven2/），在其中集合可以找到任何的流行开源类库；（干货——引入了中央仓库，当然与之对应的还有本地仓库）3.2）本地仓库：用户目录/.m2/repository/ （用户目录如 C:\Users\lenovo） ；(t2)
4）配置用户范围 settings.xml
4.1）大多数用户需要将 M2_HOME/conf/settings.xml（dir1） copy 到 本地仓库的父目录下（dir2）（即它们是兄弟，如上图所示）4.2）reasons：
reason1）dir1 是全局配置，该机子上的所有用户都要受到该配置的影响，而dir2 是用户范围的，只对当前用户（lenovo）产生影响；reason2）配置用户范围 settting.xml 文件还便于maven升级。直接修改 conf/settings.xml 文件 会导致 maven 升级不便；
Attention）
A1）maven 能够帮助我们 清理，编译，测试，打包，部署，然后得到 final products；A2）通过 其 衍生工具 Nexus，我们还能对开源类库（如jar）进行快速地搜索；
【1】编写POM
1）Hello的 pom.xml 文件如下：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.maven.chapter3</groupId>
<artifactId>service</artifactId>
<version>1.0-SNAPSHOT</version>
<name>service says hello maven.</name>
</project>
对以上代码的分析（Analysis）：
A1）project：是所有 pom.xml 的根元素，它声明了一些 POM 相关的命名空间和 xsd 元素；A2）modelVersion： 指定了当前 pom 模型的版本，对于 maven 3来说，它只能是4.0.0A3）groupId：定义了项目输入那个组；A4）artifactId：定义了当前maven项目在组中唯一的id号码；A5）version：指定了Hello 项目当前的版本；A6）name：声明了一个对于用户更为友好的项目名称；
Attention）
A1）要知道， groupId + artifactId + version 组成了一个坐标，当然你也看做是 三维坐标用来定位 所需 类库的位置；（干货——坐标==groupId + artifactId + version，坐标的作用是定位 依赖类库的位置）A2）看个荔枝：以junit为例，其jar list 如下所示；如果要用 Junit4.7的话，则其 坐标定义如下：<groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.7</version>(t3)
(t4)
【2】编写主代码
1）Hello.java 代码如下：
package com.maven.chapter3.service;
public class Hello {
public String sayHello() {
return "hello maven.";
}
public static void main(String[] args) {
System.out.println((new Hello()).sayHello());
}
}
2）关于主代码有两点注意（Attention）：
A1）在 大多数case下：应该把项目主代码放到 src/main/java 目录下；maven 会自动搜寻该目录找到项目主代码；A2）该java类的包名是 com.maven.chapter3.service：这与之前在 pom 中定义的 groupId 和 artifactID 要吻合；
3）代码编写完毕后，使用maven进行编译（mvn clean compile）
对以上console info的分析（Analysis）：
A1）以上命令所进行的任务有： clean:clean, resources:resource, compiler:compile；A2）clean 告诉 maven 清理输出目录 target/；compile 编译项目主代码；resources:resources 任务（未定义项目资源，略过）；
【3】编写测试代码（测试用例）
1）HelloTest.java 源码如下：
package com.maven.chapter3.service;
import static org.junit.Assert.*;
import org.junit.Test;
public class HelloTest {
@Test
public void testSayHello() {
Hello hello = new Hello();
String result = hello.sayHello();
assertEquals("hello maven.", result);
}
}
2）关于测试代码有两点注意（Attention）：
A1）在 大多数case下：应该把测试代码放到 src/test/java 目录下；maven 会自动搜寻该目录找到项目测试代码；A2）测试代码需要依赖 Junit，添加对JUnit的依赖，pom.xml文件如下：
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.maven.chapter3</groupId> <artifactId>service</artifactId> <version>1.0-SNAPSHOT</version> <name>service says hello maven.</name> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.7</version> <scope>test</scope> </dependency> </dependencies> </project>
对以上代码的分析（Analysis）：
A1）以上xml文件有 scope元素，scope表示依赖范围；A2）依赖范围scope==test：则表明该依赖只对测试有效；换句话说，测试代码中 import JUnit 代码是没有问题的，但如果在主代码中 import JUnit，就会造成编译错误；A3）依赖范围（default）scope==compile：如果不声明依赖访问，默认是compile，这样表示该依赖对主代码和测试代码都有效；
3）调用maven执行测试（mvn clean test）
【4】打包和运行
1）intro： 简单地执行命令 mvn clean package 进行打包；
D:\classical_books\java_set\maven_in_action\mycode\chapter3>mvn clean package [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building service says hello maven. 1.0-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ service --- // clean task. [INFO] Deleting D:\classical_books\java_set\maven_in_action\mycode\chapter3\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ service --- // resources task. [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\main\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ service --- // compile task. [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\classes [INFO] [INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ service --- // testResources task. [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\test\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ service --- // testCompile task. [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\test-classes [INFO] [INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ service --- // test task. [INFO] Surefire report directory: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\surefire-reports ------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.maven.chapter3.service.HelloTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.055 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ service --- [INFO] Building jar: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar // jar task 负责打包. [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS // 构建成功. [INFO] ------------------------------------------------------------------------ [INFO] Total time: 3.599 s [INFO] Finished at: 2016-06-16T22:18:46+08:00 [INFO] Final Memory: 17M/168M [INFO] ------------------------------------------------------------------------
2）如何才能让其他项目直接引用这个 jar呢？ 执行mvn clean install 安装 jar 到本地仓库；
D:\classical_books\java_set\maven_in_action\mycode\chapter3>mvn clean install [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building service says hello maven. 1.0-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ service --- [INFO] Deleting D:\classical_books\java_set\maven_in_action\mycode\chapter3\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ service --- [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\main\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ service --- [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\classes [INFO] [INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ service --- [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\test\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ service --- [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\test-classes [INFO] [INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ service --- [INFO] Surefire report directory: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\surefire-reports ------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.maven.chapter3.service.HelloTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.051 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ service --- [INFO] Building jar: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar [INFO] [INFO] --- maven-install-plugin:2.4:install (default-install) @ service --- Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0.5/plexus-utils-3.0.5.pom Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0.5/plexus-utils-3.0.5.pom (3 KB at 1.3 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-digest/1.0/plexus-digest-1.0.pom Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-digest/1.0/plexus-digest-1.0.pom (2 KB at 2.5 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-components/1.1.7/plexus-components-1.1.7.pom Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-components/1.1.7/plexus-components-1.1.7.pom (5 KB at 10. Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0.5/plexus-utils-3.0.5.jar Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-digest/1.0/plexus-digest-1.0.jar Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-digest/1.0/plexus-digest-1.0.jar (12 KB at 13.7 KB/sec) Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/3.0.5/plexus-utils-3.0.5.jar (226 KB at 189.1 KB/se [INFO] Installing D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar to C:\Users\lenovo\.m2\ ven\chapter3\service\1.0-SNAPSHOT\service-1.0-SNAPSHOT.jar [INFO] Installing D:\classical_books\java_set\maven_in_action\mycode\chapter3\pom.xml to C:\Users\lenovo\.m2\repository\com\maven\cha -SNAPSHOT\service-1.0-SNAPSHOT.pom [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 7.750 s [INFO] Finished at: 2016-06-16T22:24:09+08:00 [INFO] Final Memory: 19M/165M [INFO] ------------------------------------------------------------------------
3）对执行命令的分析：
A1）maven的命令列表有：mvn clean compile, mvn clean test, mvn clean install；A2）命令执行顺序： 执行test之前要先执行 compile，执行package 之前要执行test，执行install 之前要执行packge；所以如果 键入 mvn clean install ，则执行顺序是 compile->test->package->install ；
4） 生成可执行的jar 文件，
4.1）默认情况下：打包生成的 jar 是不能够直接运行的，因为带有main 方法的类信息不回添加到 manifest中；4.2）生成可执行的jar 文件： 需要借助maven-shade-plugin，配置该插件如下；<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.maven.chapter3</groupId> <artifactId>service</artifactId> <version>1.0-SNAPSHOT</version> <name>service says hello maven.</name> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.7</version> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <!-- maven-shade-plugin configuration --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-shade-plugin</artifactId> <version>1.2.1</version> <executions> <execution> <phase>package</phase> <goals> <goal>shade</goal> </goals> <configuration> <transformers> <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"> <mainClass>com.maven.chapter3.service.Hello</mainClass> </transformer> </transformers> </configuration> </execution> </executions> </plugin> </plugins> </build> </project>
4.3）执行 mvn clean install 并查看目录树D:\classical_books\java_set\maven_in_action\mycode\chapter3>mvn clean install // 执行 mvn clean install [INFO] Scanning for projects... [WARNING] [WARNING] Some problems were encountered while building the effective model for com.maven.chapter3:service:jar:1.0-SNAPSHOT [WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin is missing. @ line 22, column 15 [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 service says hello maven. 1.0-SNAPSHOT [INFO] ------------------------------------------------------------------------ Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-shade-plugin/1.2.1/maven-shade-plugin-1.2.1.pom Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-shade-plugin/1.2.1/maven-shade-plugin-1.2.1.pom (6 KB at 3.1 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/13/maven-plugins-13.pom Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/13/maven-plugins-13.pom (12 KB at 27.3 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-shade-plugin/1.2.1/maven-shade-plugin-1.2.1.jar Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-shade-plugin/1.2.1/maven-shade-plugin-1.2.1.jar (67 KB at 112.0 KB/sec ) [INFO] [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ service --- [INFO] Deleting D:\classical_books\java_set\maven_in_action\mycode\chapter3\target [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ service --- [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\main\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ service --- [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\classes [INFO] [INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ service --- [WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\classical_books\java_set\maven_in_action\mycode\chapter3\src\test\resources [INFO] [INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ service --- [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent! [INFO] Compiling 1 source file to D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\test-classes [INFO] [INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ service --- [INFO] Surefire report directory: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\surefire-reports ------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.maven.chapter3.service.HelloTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.045 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ service --- [INFO] Building jar: D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar [INFO] [INFO] --- maven-shade-plugin:1.2.1:shade (default) @ service --- Downloading: https://repo.maven.apache.org/maven2/asm/asm-commons/3.1/asm-commons-3.1.pom Downloaded: https://repo.maven.apache.org/maven2/asm/asm-commons/3.1/asm-commons-3.1.pom (436 B at 1.0 KB/sec) Downloading: https://repo.maven.apache.org/maven2/asm/asm-tree/3.1/asm-tree-3.1.pom Downloaded: https://repo.maven.apache.org/maven2/asm/asm-tree/3.1/asm-tree-3.1.pom (425 B at 1.1 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/shared/maven-dependency-tree/1.1/maven-dependency-tree-1.1.pom Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/shared/maven-dependency-tree/1.1/maven-dependency-tree-1.1.pom (3 KB at 6.5 KB/sec) Downloading: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/1.5.5/plexus-utils-1.5.5.jar Downloading: https://repo.maven.apache.org/maven2/asm/asm-commons/3.1/asm-commons-3.1.jar Downloading: https://repo.maven.apache.org/maven2/asm/asm-tree/3.1/asm-tree-3.1.jar Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/shared/maven-dependency-tree/1.1/maven-dependency-tree-1.1.jar Downloaded: https://repo.maven.apache.org/maven2/asm/asm-commons/3.1/asm-commons-3.1.jar (32 KB at 72.6 KB/sec) Downloaded: https://repo.maven.apache.org/maven2/asm/asm-tree/3.1/asm-tree-3.1.jar (22 KB at 17.1 KB/sec) Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/shared/maven-dependency-tree/1.1/maven-dependency-tree-1.1.jar (34 KB at 26.4 KB/sec ) Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-utils/1.5.5/plexus-utils-1.5.5.jar (246 KB at 73.4 KB/sec) [INFO] Replacing original artifact with shaded artifact. [INFO] Replacing D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar with D:\classical_books\java_set\maven_in _action\mycode\chapter3\target\service-1.0-SNAPSHOT-shaded.jar [INFO] [INFO] --- maven-install-plugin:2.4:install (default-install) @ service --- [INFO] Installing D:\classical_books\java_set\maven_in_action\mycode\chapter3\target\service-1.0-SNAPSHOT.jar to C:\Users\lenovo\.m2\repository\com\ma ven\chapter3\service\1.0-SNAPSHOT\service-1.0-SNAPSHOT.jar [INFO] Installing D:\classical_books\java_set\maven_in_action\mycode\chapter3\pom.xml to C:\Users\lenovo\.m2\repository\com\maven\chapter3\service\1.0 -SNAPSHOT\service-1.0-SNAPSHOT.pom [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 11.789 s [INFO] Finished at: 2016-06-17T08:51:15+08:00 [INFO] Final Memory: 20M/172M [INFO] ------------------------------------------------------------------------ D:\classical_books\java_set\maven_in_action\mycode\chapter3>tree /f // 查看目录树. 卷 软件 的文件夹 PATH 列表 卷序列号为 0006-7799 D:. │ filelist.txt │ pom.xml │ pom.xml.bak │ ├─src │ ├─main │ │ └─java │ │ └─com │ │ └─maven │ │ └─chapter3 │ │ └─service │ │ Hello.java │ │ │ └─test │ └─java │ └─com │ └─maven │ └─chapter3 │ └─service │ HelloTest.java │ └─target │ original-service-1.0-SNAPSHOT.jar │ service-1.0-SNAPSHOT.jar │ ├─classes │ └─com │ └─maven │ └─chapter3 │ └─service │ Hello.class │ ├─maven-archiver │ pom.properties │ ├─maven-status │ └─maven-compiler-plugin │ ├─compile │ │ └─default-compile │ │ createdFiles.lst │ │ inputFiles.lst │ │ │ └─testCompile │ └─default-testCompile │ createdFiles.lst │ inputFiles.lst │ ├─surefire-reports │ com.maven.chapter3.service.HelloTest.txt │ TEST-com.maven.chapter3.service.HelloTest.xml │ └─test-classes └─com └─maven └─chapter3 └─service HelloTest.class对以上目录的分析（Analysis）：
A1）打开target，可以看到 有两个jar 文件 original-service-1.0-SNAPSHOT.jar 和 service-1.0-SNAPSHOT.jar；前者是原始的jar， 后者是带有 Main-class 信息的可运行jar；A2）打开可运行jar（service-1.0-SNAPSHOT.jar） 的 META-INF/MANIFEST.MF，可以看到如下信息：Manifest-Version: 1.0 Archiver-Version: Plexus Archiver Built-By: lenovo Created-By: Apache Maven 3.3.9 Build-Jdk: 1.8.0_60 Main-Class: com.maven.chapter3.service.Hello // highlight line.
4.4）执行 service-1.0-SNAPSHOT.jar 文件D:\classical_books\java_set\maven_in_action\mycode\chapter3>java -jar target\service-1.0-SNAPSHOT.jar hello maven. // 执行结果.
【5】使用 Archetype 生成项目骨架
0）intro to Archetype（骨架）：我们把maven基本的目录结构和 pom.xml 文件内容（见上述目录树） 称为项目的骨架；
（干货——引入骨架）
1）problem + solution
1.1）problem：后续的项目需要用到 Hello 项目，不可能每次都重复上述steps 来构建 Hello 项目；1.2）solution：使用 maven archetype 来创建该项目的骨架，以便于后续项目引用；
2）生成项目骨架命令：mvn archetype:generate，该命令实际上是运行插件 maven-archetype-plugin；
3）看个荔枝： 为 Hello 项目生成骨架
step1）输入 mvn archetype:generate 生成骨架
step2）骨架生成后的文件树D:\classical_books\java_set\maven_in_action\mycode\archetype_test>tree /f 卷 软件 的文件夹 PATH 列表 卷序列号为 0006-7799 D:. └─service │ pom.xml │ └─src ├─main │ └─java │ └─com │ └─maven │ └─chapter3 │ └─service │ App.java │ └─test └─java └─com └─maven └─chapter3 └─service AppTest.java
Attention）
A1）要将某项目生成骨架，这之前要安装该项目到本地仓库；A2）退出当前项目文件，即建立一个空文件夹，然后再进入到该空文件夹 生成骨架（mvn archetype:generate）