javac不承认

Question

What can I do when I keep receiving the error

'javac' is not recognized as an internal or external command, operable program or batch file

when I want to compile my jar or .class file?

Thanks

Answer 1

确保％JAVA_HOME％/ bin位于％PATH％（或* nix中的$ PATH上的$ JAVA_HOME）。

Answer 2

It means that it is not in your path. You have the following options:

1) Change to the directory where javac lives before calling it.

2) Use the full path to javac when making the call, eg C:\\java\\jdk1.6.0_12\\bin\\javac ...

3) Add the javac directory to the PATH environment variable

Answer 3

This just means that javac isn't in your PATH variable.

On Windows, you just have to add the folder that contains javac.exe to the PATH environment variable (Win+Pause/Break).

On Linux/Mac/Unix, just append that directory to $PATH in .bashrc or similar.

Answer 4

The error that you are seeing is generated by Windows, and isn't specific to Java. That error means that you typed a command and Windows could not find the command by that name.

The easiest way of rectifying the situation is to ensure that Java is properly installed in your system's PATH .

First, ensure that you have a JDK installed (and not just a JRE). Your next best bet is to add an environment variable called JAVA_HOME and point it at the base install directory for the version of Java that you installed.

Next, modify your PATH environment variable by prepending the string %JAVA_HOME%\\bin; to whatever is already in your PATH . If you look at the contents of that directory, you will see that javac is in there (along with a number of other Java development tools).

Answer 5

You have to install JDK (which includes javac compiler) and ensure that it's in the path. See http://java.sun.com/javase/downloads/index.jsp

Answer 6

SUN教程页面中的常见错误消息

Answer 7

Even if I had

• JDK installed
• JAVA_HOME defined
• %JAVA_HOME%\\bin present in my %PATH%

I still had this error. I resolved it by eliminating the JRE from my path variable. It was put before JAVA_HOME , has no javac . It seems Windows can't find javac in JAVA_HOME\\bin in this case.

Answer 8

JDK安装说明的步骤4（更新PATH变量）说明了应该做什么，以便您只需在命令提示符窗口中键入javac即可。

Answer 9

For Windows

Control Panel > System ...Then click Advanced System Setting (left pane)...then popup window will open...then click Environment Variables ...Then another window will open...click New and add enter information below

Variable name : PATH

Variable value : C:\\Program Files\\Java\\jdk1.7.0_45\\bin [* make sure this is the right path for you ]

Then it should work

Answer 10

The link below gives a step by step explanation on how to set up java_home and path variables. JAVA_HOME setup

Answer 11

• Check whether you have JDK installed; if not installed, Install
• If JDK is installed, navigate into the bin folder of the installation, and try to execute javac.
• If javac executes, proceed (+:
• If javac does not execute, check your system path, and java path, and return to 2 above!