Running Java from a Windows batch file causes the batch file to stop

Question

When I run Java from a Windows .cmd file (Vista 32-bit here), the Java command causes the batch file to stop executing additional commands.

For example, this is a simple test.cmd file:

java
java

This should cause Java to print its help message twice. However when I run it in cmd.exe, I get this:

C:\>test

C:\>java
Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)

where options include:
    -client       to select the "client" VM
    -server       to select the "server" VM
...

C:\>

The batch file simply exits when Java exits. What's going on here?

Answer 1

Another possibility is that there's a batchfile called java which is getting called, rather than the normal java.exe (though the batch file may invoke the executable, possibly also setting up things like the CLASSPATH beforehand). Executing a batchfile from another will transfer execution to the other batchfile entirely, not returning to the invoker. To execute it and then continue execution of the original batch file, use call:

call java

And see if that makes a difference.

Answer 2

If you have both a test.bat and a test.cmd then typing test will run test.bat not test.cmd - try using the command test.cmd instead.

C:\>type test.bat
@echo off
echo a =============================================
java
echo b =============================================

C:\>type test.cmd
echo 1 -------------------------------------------------
java
echo 2 -------------------------------------------------
java
echo 3 -------------------------------------------------

C:\>test

a =============================================

Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)

where options include:
    -client       to select the "client" VM
    -server       to select the "server" VM
    -hotspot      is a synonym for the "client" VM  [deprecated]
                  The default VM is client.

...

b =============================================

C:\>

Answer 3

Quick test:

C:\> where java

With that, you can find out exactly what is being executed.