简单maven 插件项目的创建以及使用。
参考: https://maven.apache.org/guides/plugin/guide-java-plugin-development.html
https://maven.apache.org/plugin-tools/index.html
官网建议插件名称的起名为<name>-maven-plugin
有两种方式， 第一种是注解方式； 第二种是文档的方式。 下面研究其使用。
1. 注解方式
参考： https://maven.apache.org/plugin-tools/maven-plugin-tools-annotations/index.html
1. IDEA 新建项目pom 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/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>cn.qz.cloud</groupId> <artifactId>my-mvn-plugin</artifactId> <version>1.0-SNAPSHOT</version> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <!--打包方式--> <packaging>maven-plugin</packaging> <dependencies> <!-- dependencies to annotations --> <dependency> <groupId>org.apache.maven.plugin-tools</groupId> <artifactId>maven-plugin-annotations</artifactId> <version>3.6.2</version> <optional>true</optional> <!-- annotations are not used at runtime because @Retention(value=CLASS), they are needed only to build the plugin --> </dependency> <dependency> <groupId>org.apache.maven</groupId> <artifactId>maven-core</artifactId> <version>3.3.9</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-plugin-plugin</artifactId> <version>3.6.2</version> </plugin> </plugins> </build> </project>
注意打包方式为maven-plugin
2. 标准注解如下:
import org.apache.maven.execution.MavenSession; import org.apache.maven.plugin.AbstractMojo; import org.apache.maven.plugin.MojoExecution; import org.apache.maven.plugin.descriptor.PluginDescriptor; import org.apache.maven.plugins.annotations.Component; import org.apache.maven.plugins.annotations.Execute; import org.apache.maven.plugins.annotations.InstantiationStrategy; import org.apache.maven.plugins.annotations.LifecyclePhase; import org.apache.maven.plugins.annotations.Mojo; import org.apache.maven.plugins.annotations.Parameter; import org.apache.maven.plugins.annotations.ResolutionScope; import org.apache.maven.project.MavenProject; import org.apache.maven.settings.Settings; /** * Mojo Description. @Mojo( name = "<goal-name>" ) is the minimal required annotation. * @since <since-text> * @deprecated <deprecated-text> */ @Mojo( name = "<goal-name>", aggregator = <false|true>, configurator = "<role hint>", executionStrategy = "<once-per-session|always>", // (unsupported since Maven 3.0) inheritByDefault = <true|false>, // (unsupported since Maven 3.0) instantiationStrategy = InstantiationStrategy.<strategy>, defaultPhase = LifecyclePhase.<phase>, requiresDependencyResolution = ResolutionScope.<scope>, requiresDependencyCollection = ResolutionScope.<scope>, // (since Maven 3.0) requiresDirectInvocation = <false|true>, // (unsupported since Maven 3.0) requiresOnline = <false|true>, requiresProject = <true|false>, requiresReports = <false|true>, // (unsupported since Maven 3.0) threadSafe = <false|true> ) // (since Maven 3.0) @Execute( goal = "<goal-name>", phase = LifecyclePhase.<phase>, lifecycle = "<lifecycle-id>" ) public class MyMojo extends AbstractMojo { /** * @since <since-text> * @deprecated <deprecated-text> */ @Parameter( name = "parameter", alias = "myAlias", property = "a.property", defaultValue = "an expression, possibly with ${variables}", readonly = <false|true>, required = <false|true> ) private String parameter; @Component( role = MyComponentExtension.class, hint = "..." ) private MyComponent component; // sample objects taken from Maven API through PluginParameterExpressionEvaluator @Parameter( defaultValue = "${session}", readonly = true ) private MavenSession session; @Parameter( defaultValue = "${project}", readonly = true ) private MavenProject project; @Parameter( defaultValue = "${mojoExecution}", readonly = true ) private MojoExecution mojo; @Parameter( defaultValue = "${plugin}", readonly = true ) // Maven 3 only private PluginDescriptor plugin; @Parameter( defaultValue = "${settings}", readonly = true ) private Settings settings; @Parameter( defaultValue = "${project.basedir}", readonly = true ) private File basedir; @Parameter( defaultValue = "${project.build.directory}", readonly = true ) private File target; public void execute() { ... } }
可以看到有许多内置的属性以及对象，也就是maven 可以直接获取的相关变量。
1. org.apache.maven.plugins.annotations.Mojo 注解如下：
package org.apache.maven.plugins.annotations; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Inherited; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * This annotation will mark your class as a Mojo (ie. goal in a Maven plugin). * * @author Olivier Lamy * @since 3.0 */ @Documented @Retention( RetentionPolicy.CLASS ) @Target( ElementType.TYPE ) @Inherited public @interface Mojo { /** * goal name (required). * @return the goal name */ String name(); /** * default phase to bind your mojo. * @return the default phase */ LifecyclePhase defaultPhase() default LifecyclePhase.NONE; /** * the required dependency resolution scope. * @return the required dependency resolution scope */ ResolutionScope requiresDependencyResolution() default ResolutionScope.NONE; /** * the required dependency collection scope. * @return the required dependency collection scope */ ResolutionScope requiresDependencyCollection() default ResolutionScope.NONE; /** * your Mojo instantiation strategy. (Only <code>per-lookup</code> and <code>singleton</code> are supported) * @return the instantiation strategy */ InstantiationStrategy instantiationStrategy() default InstantiationStrategy.PER_LOOKUP; /** * execution strategy: <code>once-per-session</code> or <code>always</code>. * @return <code>once-per-session</code> or <code>always</code> * * @deprecated unused */ @Deprecated String executionStrategy() default "once-per-session"; /** * does your mojo requires a project to be executed? * @return requires a project */ boolean requiresProject() default true; /** * does your mojo requires a reporting context to be executed? * @return requires a reporting context * * @deprecated unused */ @Deprecated boolean requiresReports() default false; /** * if the Mojo uses the Maven project and its child modules. * @return uses the Maven project and its child modules */ boolean aggregator() default false; /** * can this Mojo be invoked directly only? * @return invoked directly only * * @deprecated unused */ @Deprecated boolean requiresDirectInvocation() default false; /** * does this Mojo need to be online to be executed? * @return need to be online */ boolean requiresOnline() default false; /** * @deprecated unused */ @Deprecated boolean inheritByDefault() default true; /** * own configurator class. * @return own configurator class */ String configurator() default ""; /** * is your mojo thread safe (since Maven 3.x)? * @return is thread safe */ boolean threadSafe() default false; }