kettle8.2 java调用kettle API 自动生成Transformation转换

import java.io.File;

import org.apache.commons.io.FileUtils;
import org.pentaho.di.core.KettleEnvironment;
import org.pentaho.di.core.database.DatabaseMeta;
import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.core.plugins.PluginRegistry;
import org.pentaho.di.core.plugins.StepPluginType;
import org.pentaho.di.core.xml.XMLHandler;
import org.pentaho.di.repository.kdr.KettleDatabaseRepository;
import org.pentaho.di.repository.kdr.KettleDatabaseRepositoryMeta;
import org.pentaho.di.trans.Trans;
import org.pentaho.di.trans.TransHopMeta;
import org.pentaho.di.trans.TransMeta;
import org.pentaho.di.trans.step.StepMeta;
import org.pentaho.di.trans.steps.insertupdate.InsertUpdateMeta;
import org.pentaho.di.trans.steps.tableinput.TableInputMeta;
import org.w3c.dom.Document;

public class KettleGenerateTrans {
    
    public static KettleGenerateTrans transDemo;
    
    // 两个库中的表名
    public static String bjdt_tablename = "acc_repayschedule";
    public static String kettle_tablename = "acc_repayschedule";
     
    // 数据库连接信息,适用于DatabaseMeta其中 一个构造器DatabaseMeta(String xml)
    public static final String[] databasesXML = {
           "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
             "<connection>" +
               "<name>kettle</name>" +
               "<server>127.0.0.1</server>" +
               "<type>MySQL</type>" +
               "<access>Native</access>" + 
               "<database>kettledb</database>" +
               "<port>3306</port>" +
               "<username>kettle</username>" +
               "<password>kettle123</password>" +
             "<attributes>"+
             "<attribute><code>EXTRA_OPTION_ORACLE.characterEncoding</code><attribute>utf-8</attribute></attribute>"+
             "</attributes>"+  
             "</connection>"
             ,
             "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +