unable to create a Database Connection异常

问题与解决

在使用启动kettle过程中出现
Kettle / Data Integration - unable to create a Database Connection (XulException: java.lang.reflect.InvocationTargetException)异常，经过一两个小时的排查，发现是版本不对应造成的，现将其记录下来。

刚开始以为是由于jdk环境变量没有显式地配置造成的，但是将其配置后还是有这个问题。由于我下载的是最新的Pentaho Data Integration (or kettle) 8.2.0 版本，在考虑是不是kettle版本太高，与jdk版本不兼容？之后降低kettle版本后还是有这个问题，然后又将最新的jdk11.0版本改用jdk8之后才正确启动kettle。

总结，最新的kettle所需要的jdk版本不能过高，这里我使用的搭配是：kettle8.2 + jdk8.0 + mysql-connector-java-5.1.41.tar.gz。

kettle创建连接无法测试通过

在使用kettle创建连接测试过程中，出现如下的问题：
错误连接数据库 [local_test_indicator] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database

Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Unable to load authentication plugin ‘caching_sha2_password’.

org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database

Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Unable to load authentication plugin ‘caching_sha2_password’.

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:83)
at org.pentaho.di.core.database.DatabaseFactory.getConnectionTestResults(DatabaseFactory.java:112)
at org.pentaho.di.core.database.DatabaseMeta.testConnectionSuccess(DatabaseMeta.java:2811)
at org.pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:621)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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$4.widgetSelected(SwtButton.java:137)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.notifyListeners(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:820)
at org.eclipse.jface.window.Window.open(Window.java:796)
at org.pentaho.di.ui.xul.KettleDialog.show(KettleDialog.java:80)
at org.pentaho.di.ui.xul.KettleDialog.show(KettleDialog.java:47)
at org.pentaho.di.ui.core.database.dialog.XulDatabaseDialog.open(XulDatabaseDialog.java:116)
at org.pentaho.di.ui.core.database.dialog.DatabaseDialog.open(DatabaseDialog.java:61)
at org.pentaho.di.ui.trans.step.BaseStepDialog.showDbDialogUnlessCancelledOrValid(BaseStepDialog.java:808)
at org.pentaho.di.ui.trans.step.BaseStepDialog$AddConnectionListener.widgetSelected(BaseStepDialog.java:1487)
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.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.notifyListeners(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.trans.steps.tableinput.TableInputDialog.open(TableInputDialog.java:436)
at org.pentaho.di.ui.spoon.delegates.SpoonStepsDelegate.editStep(SpoonStepsDelegate.java:120)
at org.pentaho.di.ui.spoon.Spoon.editStep(Spoon.java:8662)
at org.pentaho.di.ui.spoon.trans.TransGraph.editStep(TransGraph.java:3293)
at org.pentaho.di.ui.spoon.trans.TransGraph.mouseDoubleClick(TransGraph.java:785)
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.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.notifyListeners(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:1381)
at org.pentaho.di.ui.spoon.Spoon.waitForDispose(Spoon.java:7817)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:9179)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:707)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.pentaho.commons.launcher.Launcher.main(Launcher.java:92)

Caused by: org.pentaho.di.core.exception.KettleDatabaseException:
Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Unable to load authentication plugin ‘caching_sha2_password’.

at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:583)
at org.pentaho.di.core.database.Database.normalConnect(Database.java:456)
... 65 more

Caused by: java.sql.SQLException: Unable to load authentication plugin ‘caching_sha2_password’.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:868)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:864)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1746)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2205)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2236)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2035)
at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:790)
at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:208)
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:567)
… 66 more

主机名 : localhost
端口 : 3306
数据库名 : system_unit_test_local

这里我尝试了https://bbs.csdn.net/topics/390184735和https://stackoverflow.com/questions/11634181/pentaho-data-integration-sql-connection中的各种方法，最后将原来使用的mysql-connector-java-5.1.41-bin.jar换为mysql-connector-java-8.0.14.jar连接器放到/usr/local/soft/data-integration/lib目录下(这里我将kettle安装在/usr/local/soft目录下的data-integration中)，测试通过了。可能是由于我用的是最新的kettle8.2版本的缘故，所以mysql-connector-java的版本也需要较高吧。

学习文档：

kettle安装过程：https://blog.csdn.net/sinat_30316741/article/details/80054580
使用kettle跨库同步表数据：https://blog.csdn.net/fantasic_van/article/details/77864517
kettle安装以及运行注意事项：https://blog.csdn.net/weinierzui/article/details/77931346
详解kettle数据同步-图文：https://blog.csdn.net/qq_35092224/article/details/79994171

参考：

https://community.hitachivantara.com/thread/13062-kettle-data-integration-unable-to-create-a-database-connection-xulexception-javalangreflectinvocationtargetexception

https://bbs.csdn.net/topics/390184735
https://blog.csdn.net/philip502/article/details/17763323
https://stackoverflow.com/questions/11634181/pentaho-data-integration-sql-connection