我的电脑装的是Oracle 11g

因为要JDK的支持，java才能连接数据库，所以装了JDK1.7，请注意接下来的话：

装JDK时免不了要装jre，但是：

　　　　jdk和jre不能都安装在java文件夹的根目录下，jdk和jre安装在同一文件夹会出错；

装好Oracle，替换掉sqldeveloper，以为万事大吉的时候，意外发生了：

　　打开Oracle里面的SQL developer出现了以下错误，但是顺利打开了，不爽

1 Exception initializing 'oracle.dbtools.raptor.plsql.PLSQLAddin' in extension 'Or 2 acle SQL Developer': java.lang.NoClassDefFoundError: com/sun/jdi/Bootstrap 3   at oracle.jdevimpl.debugger.jdi.DebugJDIConnector.getVersion(DebugJDICon 4 nector.java:30) 5   at oracle.jdevimpl.debugger.support.DebugFactory.
      
       (DebugFactory.j 6 ava:81) 7   at oracle.dbtools.raptor.plsql.PLSQLAddin.initialize(PLSQLAddin.java:96) 8  9   at oracle.ideimpl.extension.AddinManagerImpl.initializeAddin(AddinManage10 rImpl.java:407)11   at oracle.ideimpl.extension.AddinManagerImpl.initializeAddins(AddinManag12 erImpl.java:214)13   at oracle.ideimpl.extension.AddinManagerImpl.initProductAndUserAddins(Ad14 dinManagerImpl.java:128)15   at oracle.ide.IdeCore.initProductAndUserAddins(IdeCore.java:1941)16   at oracle.ide.IdeCore.startupImpl(IdeCore.java:1565)17   at oracle.ide.Ide.startup(Ide.java:703)18   at oracle.ideimpl.DefaultIdeStarter.startIde(DefaultIdeStarter.java:35)19   at oracle.ideimpl.Main.start(Main.java:184)20   at oracle.ideimpl.Main.main(Main.java:146)21  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)22   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)23   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)24   at java.lang.reflect.Method.invoke(Unknown Source)25   at oracle.ide.boot.PCLMain.callMain(PCLMain.java:62)26   at oracle.ide.boot.PCLMain.main(PCLMain.java:54)27   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)28   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)29   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)30   at java.lang.reflect.Method.invoke(Unknown Source)31   at oracle.classloader.util.MainClass.invoke(MainClass.java:128)32   at oracle.ide.boot.IdeLauncher.bootClassLoadersAndMain(IdeLauncher.java:33 189)34   at oracle.ide.boot.IdeLauncher.launchImpl(IdeLauncher.java:89)35   at oracle.ide.boot.IdeLauncher.launch(IdeLauncher.java:65)36   at oracle.ide.boot.IdeLauncher.main(IdeLauncher.java:54)37   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)38   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)39   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)40   at java.lang.reflect.Method.invoke(Unknown Source)41   at oracle.ide.boot.Launcher.invokeMain(Launcher.java:713)42   at oracle.ide.boot.Launcher.launchImpl(Launcher.java:115)43   at oracle.ide.boot.Launcher.launch(Launcher.java:68)44   at oracle.ide.boot.Launcher.main(Launcher.java:57)45 Caused by: oracle.classloader.util.AnnotatedClassNotFoundException:46 47   缺少类: com.sun.jdi.Bootstrap48 49   从属类: oracle.jdevimpl.debugger.jdi.DebugJDIConnector50   加载器: ide-global:11.1.1.0.051   代码源: /D:/Oracle11g/product/11.2.0/dbhome_1/sqldeveloper/jdev/exte52 nsions/oracle.jdeveloper.runner.jar53   配置: extension jar in D:\Oracle11g\product\11.2.0\dbhome_1\sqldevelop54 er\jdev\extensions55 56 此加载操作最初是在 ide-global:11.1.1.0.0 处使用 loadClass() 方法进行的。57 58 缺少的类在系统上的任何代码源或加载器中均未提供。59   at oracle.classloader.PolicyClassLoader.handleClassNotFound(PolicyClassL60 oader.java:2190)61   at oracle.classloader.PolicyClassLoader.internalLoadClass(PolicyClassLoa62 der.java:1733)63   at oracle.classloader.PolicyClassLoader.access$000(PolicyClassLoader.jav
      

查来查去都没有解决~！后来发现其实挺简单的：在所有程序里有一个jre的程序：Java Runtime Environment

只要将jre那部分的程序卸载掉，就正常的跑起来了