開發Maven插件

　　Mojo: Maven plain Old Java Object

1、插件命名規則：maven-<yourplugin>-plugin是Maven的保留欄位，不允許使用，我們可以用<myplugin>-maven-plugin來命名自己開發的插件。

2、自定義插件代碼，註意pom文件的packaging類型是maven-plugin，否則無法識別為插件類型。

 1 import org.apache.maven.plugin.AbstractMojo;
 2 import org.apache.maven.plugin.MojoExecutionException;
 3 import org.apache.maven.plugins.annotations.Mojo;
 4 import org.apache.maven.plugins.annotations.Parameter;
 5 
 6 /**
 7  * 支持的命令:
 8  * mvn com.sample.myplugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi 
 9  * 預設輸出Hello World!
10  * 當配置了<greeting>Welcome</greeting>，輸出Welcome
11  * mvn com.sample.myplugin:hello-maven-plugin:1.0-SNAPSHOT:sayhi -Dsayhi.greeting=hello
12  * 未配置<greeting>Welcome</greeting>時輸出hello
13  */
14 @Mojo(name = "sayhi")
15 public class GreetingMojo extends AbstractMojo {
16 
17     // 參數，可以用參數表達式${project.version}
18     // 不同的參數類型的pom配置也不同
19     @Parameter(property = "sayhi.greeting", defaultValue = "Hello World!")
20     private String greeting;
21 
22     @Override
23     public void execute() throws
24             MojoExecutionException {
25         getLog().info(greeting);
26     }
27 }

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0"
 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5     <modelVersion>4.0.0</modelVersion>
 6 
 7     <groupId>com.sample.myplugin</groupId>
 8     <artifactId>hello-maven-plugin</artifactId>
 9     <version>1.0-SNAPSHOT</version>
10     <packaging>maven-plugin</packaging>
11 
19     <dependencies>
20         <dependency>
21             <groupId>org.apache.maven</groupId>
22             <artifactId>maven-plugin-api</artifactId>
23             <version>3.0</version>
24         </dependency>
25 
26         <!-- @Mojo註解的依賴包 -->
27         <dependency>
28             <groupId>org.apache.maven.plugin-tools</groupId>
29             <artifactId>maven-plugin-annotations</artifactId>
30             <version>3.4</version>
31             <scope>provided</scope>
32         </dependency>
33     </dependencies>
34 
35     <build>
36         <plugins>
37             <plugin>
38                 <!-- 使用自定義插件-->
39                 <groupId>com.sample.myplugin</groupId>
40                 <artifactId>hello-maven-plugin</artifactId>
41                 <version>1.0-SNAPSHOT</version>
42                 <configuration>
43                     <!-- greeting 是 @Parameter註解的參數-->
44                     <greeting>Welcome</greeting>
45                 </configuration>
46             </plugin>
47         </plugins>
48     </build>
49 </project>