第一步:(前提将kett中lib下的所有jar包拷贝到java项目lib目录)创建并连接资源库,如果只用这一个工作空间,可以将此段代码放入静态代码块,代码如下: 

KettleEnvironment.init();
 //创建资源库对象,此时的对象还是一个空对象
 KettleDatabaseRepository repository = new KettleDatabaseRepository();
 //创建资源库数据库对象,类似我们在spoon里面创建资源库
 //(数据库连接名称,数据库类型,连接方式,IP,数据库名,端口,用户名,密码)
 DatabaseMeta dataMeta = new DatabaseMeta("数据库连接名","数据库类型(比如MSSQL)","连接方式(例如Native(JDBC))","IP","数据库名","端口号", "用户名","密码"); 
 //资源库元对象,选择资源库(ID,名称,描述)
 KettleDatabaseRepositoryMeta kettleDatabaseMeta =new KettleDatabaseRepositoryMeta("资源库ID", "资源库名称", "这里是描述信息",dataMeta);
 //给资源库赋值
 repository.init(kettleDatabaseMeta);
 //连接资源库
 repository.connect("admin","admin");第二步:启动并运行job:
directoryInterface = repository.loadRepositoryDirectoryTree();
 JobMeta jobMeta = repository.loadJob(jobName,directoryInterface,null,null);//从资源库中加载一个job,jobName:job名
 Job job = new Job(repository,jobMeta);job.start();//启动job,默认是线程执行。
 job.waitUntilFinished();//等待job执行结束第三步:获取job状态或者停止job:
job.stopAll();//停止job
 String status=job.getStatus();//获取运行状态。至此,java调用job的基本功能已经实现,如果现在有需求是生成web service接口,提供四个方法供外界访问,分别是传入串job名并分别执行这些job(比如“jobA,jobB,JobC”)、传入一个job名获取这个job 的当前状态、传入一个job名停止运行这个job,分享代码如下:
package com.test;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import org.pentaho.di.core.KettleEnvironment;
import org.pentaho.di.core.database.DatabaseMeta;
import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.job.Job;
import org.pentaho.di.job.JobMeta;
import org.pentaho.di.repository.Repository;
import org.pentaho.di.repository.RepositoryDirectoryInterface;
import org.pentaho.di.repository.kdr.KettleDatabaseRepository;
import org.pentaho.di.repository.kdr.KettleDatabaseRepositoryMeta;import com.util.DBUtil;
public class TestOaJobX {
 private static Connection con = null;
 private static PreparedStatement pst = null;
 private static ResultSet rs = null;

 private static Repository repository;
 private static List<Job> jobs;
 private static String[] jobNameArray;
 public TestOaJobX() {
 // TODO Auto-generated constructor stub
 }
 static{
 try {
 KettleEnvironment.init();
 //创建资源库对象,此时的对象还是一个空对象
 KettleDatabaseRepository repository = new KettleDatabaseRepository();
 //创建资源库数据库对象,类似我们在spoon里面创建资源库
 //(数据库连接名称,数据库类型,连接方式,IP,数据库名,端口,用户名,密码)
 DatabaseMeta dataMeta =newDatabaseMeta("数据库连接名","数据库类型(比如MSSQL)","连接方式(例如Native(JDBC))","IP","数据库名","端口号",
 "用户名","密码");
 //资源库元对象,选择资源库(ID,名称,描述)
 KettleDatabaseRepositoryMeta kettleDatabaseMeta =new KettleDatabaseRepositoryMeta("资源库ID", "资源库名称", "这里是描述信息",dataMeta);
 //给资源库赋值
 repository.init(kettleDatabaseMeta);
 //连接资源库
 repository.connect("admin","admin");
 TestOaJobX.repository=repository;
 } catch (KettleException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 } 

 public void setJod(String jobNames) {
 //资源库目录
 RepositoryDirectoryInterface directoryInterface;
 try {
 if(TestOaJobX.jobs==null){
 directoryInterface = repository.loadRepositoryDirectoryTree();

 jobNameArray=jobNames.split(",");
 List<JobMeta> jobmetalist=new ArrayList<JobMeta>();
 for(int i=0;i<jobNameArray.length;i++){
 JobMeta jobMeta = repository.loadJob(jobNameArray[i],directoryInterface,null,null);//从资源库中加载一个job
 jobmetalist.add(jobMeta);
 }
 TestOaJobX.jobs=new ArrayList<Job>();
 for(int i=0;i<jobmetalist.size();i++){
 Job job = new Job(repository,jobmetalist.get(i));
 TestOaJobX.jobs.add(job);
 }
 }
 } catch (KettleException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }

 public void runJob(String jobNames){
 setJod(jobNames);
 String[] tmpname=jobNames.split(",");
 for(int i=0;i<jobs.size();i++){
 System.out.println("第"+(i+1)+"项作业:"+tmpname[i]+" 开始执行");
 //jobs.get(i).start();
 //jobs.get(i).run();
 try {
 jobs.get(i).execute(i, null);
 } catch (KettleException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 jobs.get(i).waitUntilFinished();
 System.out.println("第"+(i+1)+"项作业:"+tmpname[i]+" 执行完毕");
 if(jobs.get(i).getErrors()>0){
 System.out.println("第"+(i+1)+"项作业:"+tmpname[i]+" 执行失败!");
 }else{
 System.out.println("第"+(i+1)+"项作业:"+tmpname[i]+" 执行成功!");
 }
 }
 }
 public void stopJob(String jobName) {
 if(jobNameArray!=null){
 int m=0;
 for(int i=0;i<jobNameArray.length;i++){
 if(jobName.equals(jobNameArray[i])){
 m=i;
 }
 }
 jobs.get(m).stopAll();
 if(jobs.get(m).getErrors()>0){
 System.out.println("第"+(m+1)+"项作业:"+jobName+" 停止异常!");
 }else{
 System.out.println("第"+(m+1)+"项作业:"+jobName+" 停止成功!");
 }
 }else{
 System.out.println("该作业未运行");
 }
 }
 public String getStatus(String jobName) {
 if(jobNameArray!=null){
 int m=0;
 for(int i=0;i<jobNameArray.length;i++){
 if(jobName.equals(jobNameArray[i])){
 m=i;
 }
 }
 String status=jobs.get(m).getStatus();
 return status;
 }else{
 System.out.println("该作业未运行");
 return null;
 }
 }
 public void errorView(String jobName) {
 con=DBUtil.getConnection();
 String sql="select * from ERROR_LOG where KJBNAME = ? order by ERROETIME desc";
 try {
 pst=con.prepareStatement(sql);
 pst.setString(1,jobName);
 rs=pst.executeQuery();
 if(rs!=null){
 while(rs.next()){
 System.out.println(rs.getString("KJBNAME")+" "+
 rs.getString("KTRNAME")+" "+
 rs.getString("ERRORINFO")+" "+
 rs.getString("ERROETIME"));
 }
 }
 pst.close();
 rs.close();
 con.close();
 }catch(Exception e){
 e.printStackTrace();
 }
 }
}

然后生成接口就行了。

现在有一个问题有待于解决,就是job的start、run、和execute方法都可以执行job,但是用job.start后不能第二次执行这个方法,但是run和execute可以