Windows中的JDK7问题

Question

I installed JDK7 in windows. I didn't do anything more, don't confing path and classpath, this is my path enviroments:

there can find I didn't include jdk installed directory. but when I run "java -version" command in a commandline, I saw that:

but when i run "javac -version", it can't work, "javac" command undefined. If I didn't include my jdk installed directory, java and javac command must all can't work, but when in jdk7, "java" command can work, "javac" command didn't work, for solved the problem, I can include the jdk installed directory in path, but I want to know what cause the problem, is there difference between jdk7 and pre version?

Answer 1

The JDK also installs a public JRE. A public JRE adds a java.exe stub to \\windows\\system32 directory. The stub reads the registry to find out which real java.exe to execute.

Other JDK commands do not get the same treatment and require the JDK's bin directory to be on the system path, preferably before the \\windows\\system32 entry, for consistency.

Answer 2

为了使用“ javac”之类的命令，您应该在JDK本地安装中的路径中具有\\ bin目录。

Answer 3

您可能在Windows \\ system32中有java.exe，但没有javac。

Answer 4

java.exe 也是 JRE的一部分，而javac.exe 只是 JDK的一部分

Answer 5

I think what has happened is that when you installed the Environment Path that was set was pointing at the JRE bin and not the JDK bin. The JRE does not contain the javac executable. Inserting the JDK bin into the Environment Path will resolve the issue as windows will now scan that folder/location to search for the executable called javac.exe

Answer 6

You need to add your java/bin directory to the PATH enviroment variable:

something like: C:\\Program Files\\Java\\jdk1.7.0_45\\bin