问题
I have installed java on windows-64bit OS. but when I execute javac, it is failing with the
error message no such command is available". I have created following environmental variable
CLASSPATH C:\Program Files (x86)\Java\jdk1.6.0_05\lib
回答1:
Add the appropriate javac path to your PATH variable. java.exe will be found under the bin directory of your JDK. E.g.
SET PATH=%PATH%;C:\Program Files (x86)\Java\jdk1.6.0_05\bin
回答2:
Before answering your question, just wann ans this simple question : Why we need PATH and CLASSPATH?
Answer:
1) PATH: You need to set PATH to compile Java source code, create JAVA CLASS FILES and Operating System to load classes at runtime.
2) CLASSPATH: This is used by JVM and not by OS.
Answer to your question :
Just make sure you have Modified PATH variable (Windows System Environmental Variable) so that it points to bin dir which contains all exe for example: java,javac and etc. In my case it is like this : ;C:\Program Files\Java\jre7\bin.
So, it doesn't matter your system is 32 bit/64 bit until and unless you specify/Modify the PATH variable correctly.
回答3:
Actually, the most conventional way of getting it done on Windows is
- Go to Control Panel
- Click System
- Open Advanced settings
- Click Environment Variables...
Path is one of the variables under "System Variables". This is where the system will search when you try to execute a command.
- just append the full path to the Bin folder under your Java installation path. You can copy it using Windows Explorer to avoid typing it manually
- click OK to close the dialogs.
To verify, open the command window aka console window (for example, WindowsKey-R cmd.exe ) and run:
javac -version
If the java bin folder is in the path, the system will find and execute the javac.exe file located there, and you will see your Java version. Something like:
c:\>javac -version
javac 1.7.0_65
回答4:
Very Simple:
You need to set the two environment variables only; PATH and java
=>Right Click on My computer
=>Properties
=>Click on left hand side bar menu "Advanced system settings" => Click on "Environment Variables" button refer below fig.
=>Follow the below steps to Set User variable and System variable.
To Set User variable named as "PATH"
- Click on "New" button in user variables section.
- Set the variable name as "PATH" and variable value as per your java installed version.(Shown in below fig.)
To Set System variable named as "java"
Click on "New" button in System variable tab.
Set the variable name as "java" and variable value as per your java installed version.(Shown in below fig.) Refer below images for the reference.
回答5:
For me, the 'JAVA_HOME' variable should be set as a System Variable, instead of User Variable. When the 'JAVA_HOME' was changed to be a System Variable, the command 'javac' works. Also, the PATH and CLASSPATH are System Variable.
来源：https://stackoverflow.com/questions/7455753/how-to-set-the-java-path-and-classpath-in-windows-64bit