Java 通过mave命令下载jar包的示例代码

之前一直都是使用的idea,创建maven工程进行jar包导入操作，居然接到了通过java 代码导入jar包的需求，满脸的懵逼，好在功夫不负有心人，最终将其拿来了，

现在这里记录一下，方便以后学习使用；

本次采用的方案是基于pom.xml模板的形式+maven命令的方式，到仓库下载jar报错，示例代码如下：

项目依赖：

<dependency>
 <groupId>commons-io</groupId>
 <artifactId>commons-io</artifactId>
 <version>2.6</version>
</dependency>

pom.xml模板：

<?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>
 <inceptionYear>2019</inceptionYear>
 <groupId>com.tx.app</groupId>
 <artifactId>autoapi</artifactId>
 <packaging>jar</packaging>
 <version>1.0</version>
 <name>autoapi</name>
 
 
 <parent>
  <groupId>com.tx</groupId>
  <artifactId>parent-pom</artifactId>
  <version>1.0.2</version>
 </parent>
 
 <repositories>
  <repository>
   <id>autoapi</id>
   <url>远端仓库地址</url>
  </repository>
 </repositories>
 
 <build>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <version>3.0.0</version>
    <configuration>
     <artifactItems>
      <artifactItem>
       <groupId>{0}</groupId>
       <artifactId>{1}</artifactId>
       <version>{2}</version>
      </artifactItem>
     </artifactItems>
    </configuration>
   </plugin>
  </plugins>
 </build>
</project>

代码示例：

public class MavenParse {
 private static String mavenPath = "/maven/apache-maven-3.6.3/bin/mvn";
 
 private static final String MVN_PARAM = " dependency:copy -DoutputDirectory=lib -U";
 
 void downloadDependency(DependencyDTO dependencyDTO, String jarName) throws Exception {
  // 准备下载命令
  String mavenCommandPath =
   System.getProperty("os.name").toLowerCase().startsWith("win") ? "mvn" : mavenPath;
  String mvnCmd = mavenCommandPath + MVN_PARAM;
 
  // 创建下载jar包存储的位置
  File workDir = getMavenRepository(jarName);
  // 基于模板创建pom.xml
  File pomFile = new File(workDir, "pom.xml");
  String pomXml = createPomModel(dependencyDTO);
  FileUtils.writeStringToFile(pomFile, pomXml, "utf-8");
  Process process = Runtime.getRuntime().exec(mvnCmd, null, workDir);
  // 验证下载成功
  if(null == process || process.waitFor()!= 0){
   FileUtils.deleteQuietly(workDir);
   throw new Exception("下载maven包失败，请检查maven配置");
  }
 }
 
 private String createPomModel(DependencyDTO dependencyDTO) throws IOException {
 
  File pomFile = new File(getClass().getResource("/pom.xml").getFile());
  String template = FileUtils.readFileToString(pomFile, "utf-8");
  return MessageFormat.format(template,
   dependencyDTO.getGroupId(),
   dependencyDTO.getArtifactId(),
   dependencyDTO.getVersion());
 
 }
 
 /**
  * 创建jar包存储的文件夹
  * @param fileName
  * @return
  * @throws Exception
  */
 private static File getMavenRepository(String fileName)throws Exception {
 
  String parentPath = System.getProperty("user.dir")+File.separator+"automation";
  parentPath = parentPath+File.separator+"mavenParse";
  parentPath = parentPath+File.separator+FilenameUtils.getBaseName(fileName);
 
  File dir = new File(parentPath);
  try {
   FileUtils.forceMkdir(dir);
  } catch (Exception e) {
   throw new RuntimeException(e);
  }
  return dir;
 }
}

测试代码：

public static void main(String[] args) throws Exception {
 String dependency = "<dependency>\n"
  + "   <groupId>commons-io</groupId>\n"
  + "   <artifactId>commons-io</artifactId>\n"
  + "   <version>2.6</version>\n"
  + "  </dependency>";


 DependencyDTO dependencyDTO = new DependencyDTO();

 dependencyDTO.setGroupId("commons-io");
 dependencyDTO.setArtifactId("commons-io");
 dependencyDTO.setVersion("2.6");
 dependencyDTO.setPomContent(dependency);

 MavenParse parse = new MavenParse();

 parse.downloadDependency(dependencyDTO,"commons-io.jar");
}

好啦，暂时就先记录在这里，后面有机会在完善