kettle 设计完成之后，可以在设计工具中进行调用，也可以使用java代码进行调用。

1.通过文件方式执行转换。

public static void runTransfer(String[] params, String ktrPath) { 
        Trans trans = null; 
        try { 
            // // 初始化 
            // 转换元对象 
            KettleEnvironment.init();// 初始化 
            EnvUtil.environmentInit(); 
            TransMeta transMeta = new TransMeta(ktrPath); 
            // 转换 
            trans = new Trans(transMeta); 
             
            // 执行转换 
            trans.execute(params); 
            // 等待转换执行结束 
            trans.waitUntilFinished(); 
            // 抛出异常 
            if (trans.getErrors() > 0) { 
                throw new Exception( 
                        "There are errors during transformation exception!(传输过程中发生异常)"); 
            } 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 

2.通过文件方式执行job

public static void runJob(Map<String,String> maps, String jobPath) { 
        try { 
            KettleEnvironment.init(); 
            // jobname 是Job脚本的路径及名称 
            JobMeta jobMeta = new JobMeta(jobPath, null); 
            Job job = new Job(null, jobMeta); 
            // 向Job 脚本传递参数，脚本中获取参数值：${参数名} 
            // job.setVariable(paraname, paravalue); 
            Set<Entry<String, String>> set=maps.entrySet();
            for(Iterator<Entry<String, String>> it=set.iterator();it.hasNext();){
                Entry<String, String> ent=it.next();
                job.setVariable(ent.getKey(), ent.getValue()); 
            }
            job.start(); 
            job.waitUntilFinished(); 
            if (job.getErrors() > 0) { 
                throw new Exception( 
                        "There are errors during job exception!(执行job发生异常)"); 
            } 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 

3.执行资源库的中的转换。

public static void runWithDb() throws KettleException{
        KettleEnvironment.init();
        //创建DB资源库
        KettleDatabaseRepository repository=new KettleDatabaseRepository();
        DatabaseMeta databaseMeta=new DatabaseMeta("kettle","mysql","jdbc","localhost","kettle","3306","root","root");
        //选择资源库
        KettleDatabaseRepositoryMeta kettleDatabaseRepositoryMeta=new KettleDatabaseRepositoryMeta("kettle","kettle","Transformation description",databaseMeta);
        repository.init(kettleDatabaseRepositoryMeta);
        //连接资源库
        repository.connect("admin","admin");
        RepositoryDirectoryInterface directoryInterface=repository.loadRepositoryDirectoryTree();
        //选择转换
        TransMeta transMeta=repository.loadTransformation("demo1",directoryInterface,null,true,null);
        Trans trans=new Trans(transMeta);
        trans.execute(null);
        trans.waitUntilFinished();//等待直到数据结束
        if(trans.getErrors()>0){
            System.out.println("transformation error");
        }else{
            System.out.println("transformation successfully");
        }
   }

可以将转换文件存储到资源库，通过程序进行调用。

kettle 使用JAVA代码进行执行