import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.Date;
import be.ibridge.kettle.core.Const;
import be.ibridge.kettle.core.LogWriter;
import be.ibridge.kettle.core.NotePadMeta;
import be.ibridge.kettle.core.database.Database;
import be.ibridge.kettle.core.database.DatabaseMeta;
import be.ibridge.kettle.core.exception.KettleException;
import be.ibridge.kettle.trans.StepLoader;
import be.ibridge.kettle.trans.Trans;
import be.ibridge.kettle.trans.TransHopMeta;
import be.ibridge.kettle.trans.TransMeta;
import be.ibridge.kettle.trans.step.StepMeta;
import be.ibridge.kettle.trans.step.StepMetaInterface;
import be.ibridge.kettle.trans.step.selectvalues.SelectValuesMeta;
import be.ibridge.kettle.trans.step.tableinput.TableInputMeta;
import be.ibridge.kettle.trans.step.tableoutput.TableOutputMeta;
/**
*
* <p>Title:
* 本文描述了以下操作：
1） 建立一個新的轉換（transformation）
2） 把轉換（transformation）存儲爲XML文件
3） 生成需要在目標表運行的SQL語句
4） 執行轉換（transformation）
5） 刪除目標表，可以使測試程序可以反覆執行（這一點可根據需要修改）。
</p>
* <p>Description: TODO 類的功能描述</p>
* <p>Copyright: Copyright (c) 2003</p>
* @author <a href="mailto: [email protected]">洪亮</a>
* @version 1.0
* <p>------------------------------------------------------------</p>
* <p> 修改歷史 </p>
* <p> 序號 日期 時間 修 改 人 修 改 原 因</p>
* <p> 1 2006-9-20 下午05:59:06 洪亮 創建 </p>
*
*/
public class TransBuilderME
{
public static final String[] databasesXML = {
"<?xml version=/"1.0/" encoding=/"UTF-8/"?>" +
"<connection>" +
"<name>target</name>" +
"<server>192.168.169.220</server>" +
"<type>ORACLE</type>" +
"<access>Native</access>" +
"<database>NMSDB</database>" +
"<port>1521</port>" +
"<username>UCP</username>" +
"<password>UCP</password>" +
"</connection>",
"<?xml version=/"1.0/" encoding=/"UTF-8/"?>" +
"<connection>" +
"<name>source</name>" +
"<server>192.168.169.220</server>" +
"<type>ORACLE</type>" +
"<access>Native</access>" +
"<database>NMSDB</database>" +
"<port>1521</port>" +
"<username>UCP</username>" +
"<password>UCP</password>" +
"</connection>"
};
/**
* Creates a new Transformation using input parameters such as the tablename to read from.
* @param transformationName The name of the transformation
* @param sourceDatabaseName The name of the database to read from
* @param sourceTableName The name of the table to read from
* @param sourceFields The field names we want to read from the source table
* @param targetDatabaseName The name of the target database
* @param targetTableName The name of the target table we want to write to
* @param targetFields The names of the fields in the target table (same number of fields as sourceFields)
* @return A new transformation
* @throws KettleException In the rare case something goes wrong
*/
public static final TransMeta buildCopyTable(String transformationName, String sourceDatabaseName, String sourceTableName, String[] sourceFields, String targetDatabaseName, String targetTableName, String[] targetFields) throws KettleException
{
LogWriter log = LogWriter.getInstance();
try
{
//
// Create a new transformation...
//傳輸元信息
TransMeta transMeta = new TransMeta();
transMeta.setName(transformationName);//傳輸名稱
// Add the database connections
for (int i=0;i<databasesXML.length;i++)//數據庫配置信息數組
{
DatabaseMeta databaseMeta = new DatabaseMeta(databasesXML[i]);//數據庫元信息
transMeta.addDatabase(databaseMeta);//傳輸元 中加入數據庫元信息
}
DatabaseMeta sourceDBInfo = transMeta.findDatabase(sourceDatabaseName);//查找源數據庫元信息
DatabaseMeta targetDBInfo = transMeta.findDatabase(targetDatabaseName);//查找目標數據庫元信息
//
// Add a note
//
String note = "Reads information from table [" + sourceTableName+ "] on database [" + sourceDBInfo + "]" + Const.CR;
note += "After that, it writes the information to table [" + targetTableName + "] on database [" + targetDBInfo + "]";
NotePadMeta ni = new NotePadMeta(note, 150, 10, -1, -1);//註釋信息
transMeta.addNote(ni);
//
// create the source step...
//
String fromstepname = "read from [" + sourceTableName + "]";//from步驟名稱
TableInputMeta tii = new TableInputMeta();//表輸入元數據信息
tii.setDatabaseMeta(sourceDBInfo);//爲表輸入 指定 數據庫
String selectSQL = "SELECT "+Const.CR;//拼接查詢sql語句
for (int i=0;i<sourceFields.length;i++)
{
if (i>0) selectSQL+=", "; else selectSQL+=" ";
selectSQL+=sourceFields[i]+Const.CR;
}
selectSQL+="FROM "+sourceTableName;
tii.setSQL(selectSQL);//設置查詢sql語句
StepLoader steploader = StepLoader.getInstance();//？？？
String fromstepid = steploader.getStepPluginID(tii);
//步驟元數據信息
StepMeta fromstep = new StepMeta(log, fromstepid, fromstepname, (StepMetaInterface) tii);
fromstep.setLocation(150, 100);
fromstep.setDraw(true);
fromstep.setDescription("Reads information from table [" + sourceTableName + "] on database [" + sourceDBInfo + "]");
//傳輸中 添加步驟
transMeta.addStep(fromstep);
//
// add logic to rename fields
// Use metadata logic in SelectValues, use SelectValueInfo...
//選擇字段（重命名）
SelectValuesMeta svi = new SelectValuesMeta();
svi.allocate(0, 0, sourceFields.length);
for (int i = 0; i < sourceFields.length; i++)
{
//設置源字段和目標字段
svi.getMetaName()[i] = sourceFields[i];
svi.getMetaRename()[i] = targetFields[i];
}
String selstepname = "Rename field names";
//獲取步驟插件ID
String selstepid = steploader.getStepPluginID(svi);
//創建步驟元數據信息
StepMeta selstep = new StepMeta(log, selstepid, selstepname, (StepMetaInterface) svi);
selstep.setLocation(350, 100);
selstep.setDraw(true);
selstep.setDescription("Rename field names");
//添加步驟
transMeta.addStep(selstep);
//傳輸連接元數據信息（連接from和select）
TransHopMeta shi = new TransHopMeta(fromstep, selstep);
transMeta.addTransHop(shi);//添加到傳輸元對象
fromstep = selstep;//然後設置from步驟爲select步驟
//
// Create the target step...
//
//
// Add the TableOutputMeta step...
//設置目標步驟名稱
String tostepname = "write to [" + targetTableName + "]";
//表輸出元對象
TableOutputMeta toi = new TableOutputMeta();
toi.setDatabase(targetDBInfo);//設置數據庫
toi.setTablename(targetTableName);//設置表名
toi.setCommitSize(3000);//設置批量提交數
toi.setTruncateTable(true);//是否清除原有數據
//獲取步驟ID
String tostepid = steploader.getStepPluginID(toi);
//創建to步驟
StepMeta tostep = new StepMeta(log, tostepid, tostepname, (StepMetaInterface) toi);
tostep.setLocation(550, 100);
tostep.setDraw(true);
tostep.setDescription("Write information to table [" + targetTableName + "] on database [" + targetDBInfo + "]");
transMeta.addStep(tostep);//添加步驟
//
// Add a hop between the two steps...
//
//創建連接 from--to
TransHopMeta hi = new TransHopMeta(fromstep, tostep);
transMeta.addTransHop(hi);
// OK, if we're still here: overwrite the current transformation...
return transMeta;
}
catch (Exception e)
{
throw new KettleException("An unexpected error occurred creating the new transformation", e);
}
}
/**
* 1) create a new transformation
* 2) save the transformation as XML file
* 3) generate the SQL for the target table
* 4) Execute the transformation
* 5) drop the target table to make this program repeatable
*
* @param args
*/
public static void main(String[] args) throws Exception
{
long start = new Date().getTime();
// Init the logging...
LogWriter log = LogWriter.getInstance("TransBuilder.log", true, LogWriter.LOG_LEVEL_DETAILED);
// Load the Kettle steps & plugins
StepLoader stloader = StepLoader.getInstance();
if (!stloader.read())
{
log.logError("TransBuilder", "Error loading Kettle steps & plugins... stopping now!");
return;
}
// The parameters we want, optionally this can be
String fileName = "./NewTrans.xml";
String transformationName = "Test Transformation";
String sourceDatabaseName = "source";
String sourceTableName = "emp_collect";
String sourceFields[] = {
"empno",
"ename",
"job",
"mgr",
"comm",
"sal",
"deptno",
"birthday"
};
String targetDatabaseName = "target";
String targetTableName = "emp_kettle01";
String targetFields[] = {
"empno01",
"ename01",
"job01",
"mgr01",
"comm",
"sal",
"deptno",
"birthday"
};
// Generate the transformation.
//創建轉換元對象
TransMeta transMeta = TransBuilderME.buildCopyTable(
transformationName,
sourceDatabaseName,
sourceTableName,
sourceFields,
targetDatabaseName,
targetTableName,
targetFields
);
// transMeta = new TransMeta();
// Save it as a file:
//傳輸元對象 中獲得XML，並輸出
String xml = transMeta.getXML();
DataOutputStream dos = new DataOutputStream(new FileOutputStream(new File(fileName)));
dos.write(xml.getBytes("UTF-8"));
dos.close();
System.out.println("Saved transformation to file: "+fileName);
// OK, What's the SQL we need to execute to generate the target table?
//獲得sql語句，創建表語句
String sql = transMeta.getSQLStatementsString();
// Execute the SQL on the target table:
//創建表
Database targetDatabase = new Database(transMeta.findDatabase(targetDatabaseName));
targetDatabase.connect();//連接數據庫
targetDatabase.execStatements(sql);//執行sql
// Now execute the transformation...
//執行傳輸任務
Trans trans = new Trans(log, transMeta);
trans.execute(null);
trans.waitUntilFinished();//等待執行完畢
// For testing/repeatability, we drop the target table again
// targetDatabase.execStatement("drop table "+targetTableName);
targetDatabase.disconnect();//斷開數據庫連接
long end = new Date().getTime();
System.out.println("運行時間：" + (end - start) / 1000 + "秒");
long min = (end - start) / 1000 / 60;
long second = (end - start) / 1000 % 60;
System.out.println("運行時間：" + min + "分鐘" + second + "秒");
}
}