First set up the jdk environment.

After downloading, click Install. Then set the running environment parameters:

Right-click "My Computer"->Properties->Advanced->Environment Variables

System Variables->New->Variable Name: JAVA_HOME Variable value: D:\ProgramFiles\Java\jdk1.7.0 (This is my installation

The path is not fixed. For example, if you install to C:\ProgramFiles, fill in C:\ProgramFiles\Java\ jdk1.7.0)

System variables->Edit->Variable name: Path add: %JAVA_HOME%\bin; at the front of the variable value (if there is already a Path

item , no need to create a new one, add it directly at the end, but it needs to be separated from the previous items)

System variables->New->Variable name: CLASSPATH Variable value:

< p>.;%JAVA_HOME%\lib;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar;

Finally test whether the environment variables are set successfully

< p>Click Start Menu-Run-Enter cmd here-Enter-Enter javac

If the following message appears:

Usage: javac

Among them, possible options include:

-g generates all debugging information

-g:none does not generate any debugging information

-g: {lines,vars,source} Generate only some debug information

-nowarn Generate no warnings

-verbose Print messages about what the compiler is doing

< p>-deprecation Output the source location using the deprecated API

-classpath Specifies the location to find user class files

-cp Specifies the location to find user class files Location

-sourcepath Specifies the location to find input source files

-bootclasspath Overrides the location of boot class files

-extdirs Override the location of the installed extensions directory

-endorseddirs Override the location of the standard path of the signature

-d Specify the location where the generated class files are stored

-encoding Specifies the character encoding used by the source file

-source Provides source compatibility with the specified version

-target Generates a specific VM Version of class file

-version version information

-help Output summary of standard options

-X Output summary of non-standard options

-J passes directly to the runtime system

Congratulations, your Java environment variable configuration is successful!

2. If:

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

or a batch file.

It means there is an error in the Java environment variable configuration, please check it carefully!