http://javahowto.blogspot.com/2006/05/javahome-vs-javahome.html

控制面板> Java, Java选项卡，单击“查看”按钮。在运行时参数中，放入:

-Djava.home=YOUR_PATH_HERE

或者当你执行Java时，你可以在命令中添加命令行开关:

java -Djava.home=PATH SomeJavaApp

在将Java目录添加到PATH变量时，您可能希望将其放在PATH变量的开头。我有一个问题，将Java目录放在PATH的末尾将不起作用。经过检查，我在我的Windows\System32目录中找到了java.exe，看起来第一个赢了，当你的PATH中有几个同名的文件时…

你可能想在Windows/System32文件夹中找到以下文件: ——java.exe ——javaw.exe ——javaws.exe

Because, the path variable is including these files, you can get a headache trying to figure out why the java -version or javac -version keeps pointing to the old JAVA_HOME: rename those files, take out the extension with an underscore, for instance. And then, you only will have to create the JAVA_HOME variable, add it to the path variable (e.g., %JAVA_HOME%) and append the "\bin" particle. This way you need to only change the JAVA_HOME variable pointing to different JRE or JDK and have multiple installations of java just by setting JAVA_HOME.

这也意味着最好手动安装Java，不需要安装程序，这样您就可以随意使用它。

这是从www.java.com -此处设置Java环境的官方解决方案。

有针对Windows 7、Windows Vista、Windows XP、Linux/Solaris和其他shell的解决方案。

例子

Windows 7 Select Computer from the Start menu Choose System Properties from the context menu Click Advanced system settings -> Advanced tab Click on Environment Variables, under System Variables, find PATH, and click on it. In the Edit windows, modify PATH by adding the location of the class to the value for PATH. If you do not have the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value. Reopen Command prompt window, and run your Java code.

http://javahowto.blogspot.com/2006/05/javahome-vs-javahome.html

控制面板> Java, Java选项卡，单击“查看”按钮。在运行时参数中，放入:

-Djava.home=YOUR_PATH_HERE

或者当你执行Java时，你可以在命令中添加命令行开关:

java -Djava.home=PATH SomeJavaApp

以管理员身份运行Eclipse。

这解决了我的问题。我还在研究背后的逻辑。