最近在做一个项目，项目中有两个系统，A系统给B系统补录数据，所以需要进行数据的抽取和自动化的ETL。同事推荐使用KETTLE软件进行ETL数据抽取。
在数据库链接的过程中，一直报一个错误，错误日志如下：
错误连接数据库 [EAST] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Error connecting to database: (using class oracle.jdbc.driver.OracleDriver)
Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Error connecting to database: (using class oracle.jdbc.driver.OracleDriver)
Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was
at org.pentaho.di.core.database.Database.normalConnect(Database.java:472)
at org.pentaho.di.core.database.Database.connect(Database.java:370)
at org.pentaho.di.core.database.Database.connect(Database.java:341)
at org.pentaho.di.core.database.Database.connect(Database.java:331)
at org.pentaho.di.core.database.DatabaseFactory.getConnectionTestReport(DatabaseFactory.java:80)
at org.pentaho.di.core.database.DatabaseMeta.testConnection(DatabaseMeta.java:2783)
at org.pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:597)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:313)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:157)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:141)
at org.pentaho.ui.xul.swt.tags.SwtButton.access$500(SwtButton.java:43)
at org.pentaho.ui.xul.swt.tags.SwtButton$4.widgetSelected(SwtButton.java:137)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:820)
at org.eclipse.jface.window.Window.open(Window.java:796)
at org.pentaho.di.ui.xul.KettleDialog.show(KettleDialog.java:80)
at org.pentaho.di.ui.xul.KettleDialog.show(KettleDialog.java:47)
at org.pentaho.di.ui.core.database.dialog.XulDatabaseDialog.open(XulDatabaseDialog.java:116)
at org.pentaho.di.ui.core.database.dialog.DatabaseDialog.open(DatabaseDialog.java:60)
at org.pentaho.di.ui.spoon.delegates.SpoonDBDelegate.newConnection(SpoonDBDelegate.java:485)
at org.pentaho.di.ui.spoon.delegates.SpoonDBDelegate.newConnection(SpoonDBDelegate.java:472)
at org.pentaho.di.ui.spoon.Spoon.doubleClickedInTree(Spoon.java:3073)
at org.pentaho.di.ui.spoon.Spoon.doubleClickedInTree(Spoon.java:3043)
at org.pentaho.di.ui.spoon.Spoon.access$2300(Spoon.java:361)
at org.pentaho.di.ui.spoon.Spoon$26.widgetDefaultSelected(Spoon.java:6184)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:1366)
at org.pentaho.di.ui.spoon.Spoon.waitForDispose(Spoon.java:8022)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:9277)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:692)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.pentaho.commons.launcher.Launcher.main(Launcher.java:92)
Caused by: org.pentaho.di.core.exception.KettleDatabaseException:
Error connecting to database: (using class oracle.jdbc.driver.OracleDriver)
Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:585)
at org.pentaho.di.core.database.Database.normalConnect(Database.java:456)
... 48 more
Caused by: java.sql.SQLException: Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor
The Connection descriptor used by the client was:
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:261)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:439)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:582)
... 49 more
从上边看，可以看出来是因为数据库的驱动不存在，经过网上查询。得到解决方案：
在JDK的ext文件夹下放入数据库连接的jar包就行了。
哈哈哈哈哈。。。。。。。。。。。。