使用DOS shell自动检测JRE环境变量

 用DOS Shell来自动检测JRE的环境变量，通过注册表的方式 

 @echo off  echo before query  echo JAVA_HOME=%JAVA_HOME%  echo CurVer=%CurVer%  echo ==================    FOR /F "skip=2 tokens=2*" %%A IN ('REG QUERY "HKLM\Software\JavaSoft\Java Runtime Environment" /v CurrentVersion') DO set CurVer=%%B  FOR /F "skip=2 tokens=2*" %%A IN ('REG QUERY "HKLM\Software\JavaSoft\Java Runtime Environment\%CurVer%" /v JavaHome') DO (    set "JAVA_HOME=%%B"  )    echo after query  echo JAVA_HOME=%JAVA_HOME%  echo CurVer=%CurVer%  echo ==================    echo clear variables  set JAVA_HOME=  set CurVer=

  运行结果