如何在不安装整个JDK的情况下在Windows中编译Java代码？

Let’s say the runtime environment (version 1.6.0_01-b06) is already in place, but since I lack administrative privileges in this particular PC, the JDK can’t be installed. So, is there any portable JDK or standalone Java compiler for Windows that doesn’t require installation?Let’s say the runtime environment (version 1.6.