Kettle模版文件简单使用示例
KETTLE版本：4.3
1.本示例效果。
a.可以对两个库中结果相同的表进行数据迁移。
b.可选择性把源表的字段抽取到目标表。
c.一个模版即可完成一系列的数据抽取。
解决方案：
定义库表迁移流程，即，《表输入->表输出》可下载附件查看。
模版所需参数：
1.源表数据连接名称（模版文件中已经保存的连接），
2.源表抽取sql，
3.目标表连接。
4.目标表名称（事先创建好）。
5.抽取sql中要入库的字段数组。
6.目标表对应源表的字段数组。

示例具体代码：

package org.pentaho.di.trans;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.core.logging.Log4jFileAppender;import org.pentaho.di.core.logging.LogWriter;import org.pentaho.di.trans.step.StepMeta;import org.pentaho.di.trans.steps.tableinput.TableInputMeta;import org.pentaho.di.trans.steps.tableoutput.TableOutputMeta;public class TestTransMain {public static void tableToTableSimpleTemplateDemo(String tableInputConneName, String sql, String tableOutConnneName,String dest_tablename,String [] streamFields,String [] tableOutFields) throws Exception{String filename = "D:\\etl_tem\\4.3测试流程\\表输入表输出模版.ktr";String arguments[] = {};try {TransMeta meta = new TransMeta(filename);DatabaseMeta tableInputDbMeta = null;DatabaseMeta tableoutDbMeta = null;List<DatabaseMeta> list = meta.getDatabases();for(DatabaseMeta dbMeta : list){if(dbMeta.getName().equals(tableInputConneName)){tableInputDbMeta = dbMeta;}if(dbMeta.getName().equals(tableOutConnneName)){tableoutDbMeta = dbMeta;}if(tableoutDbMeta!=null && tableInputDbMeta!=null) break;}if(tableoutDbMeta==null || tableInputDbMeta==null){System.out.println("指定的数据源名称在模版文件中不存在!");return ;}StepMeta stepMeta = meta.findStep("表输入");TableInputMeta tableInput_meta = (TableInputMeta)stepMeta.getStepMetaInterface();tableInput_meta.setDatabaseMeta(tableInputDbMeta);tableInput_meta.setSQL(sql);stepMeta = meta.findStep("表输出");TableOutputMeta tableout_meta = (TableOutputMeta)stepMeta.getStepMetaInterface();tableout_meta.setDatabaseMeta(tableoutDbMeta);tableout_meta.setTablename(dest_tablename);tableout_meta.setFieldStream(streamFields);tableout_meta.setFieldDatabase(tableOutFields);Trans trans = new Trans(meta);trans.prepareExecution(arguments);trans.addTransListener(new TransAdapter() {public void transFinished(Trans trans) throws KettleException {System.out.println("流程执行完成");}});trans.startThreads();trans.waitUntilFinished();} catch (Exception e) {e.printStackTrace();}}public static void main(String[] args) {String tableInputConneName = "153ora";String sql = "SELECT  ID, NAME, SEX FROM PERSON"; String tableOutConnneName = "153ora";String dest_tablename = "TTT_Person";String [] streamFields = {"ID","NAME","SEX"};String [] tableOutFields = {"ID","NAME","SEX"};try {KettleEnvironment.init();Log4jFileAppender fileAppender = LogWriter.createFileAppender("D:\\etl_tem\\4.3测试流程\\test.log", true);LogWriter.getInstance().addAppender(fileAppender);tableToTableSimpleTemplateDemo(tableInputConneName, sql, tableOutConnneName, dest_tablename, streamFields, tableOutFields);fileAppender.close();} catch (Exception e) {e.printStackTrace();}System.out.println("主函数结束");}}