windows下jdk1.6 到jdk1.7切换，网上很多办法无效，光改环境变量没用的

装了很多jdk版本，ant时发现修改环境变量无效，一直是1.7，

1、要改注册表（前提jdk路径配置正确）

2、要改path下的文件

直接运行一下bat

@echo off 
  
   
  
:init 
  
set JAVA_HOME_1_7=E:Progra~1Javajdk1.7.0_45_32bit
  
set JAVA_HOME_1_6=E:Progra~1Javajdk1.6.0_45
  
   
  
:start 
  
echo current JKD VERSION:
  
java -version 
  
ping 127.0.0.1 -n 2 -w 1000 > nul 
  
echo. 
  
echo ============================================= 
  
echo select jdk version 
  
echo 7 
  
echo 6 
  
echo ============================================= 
  
   
  
:select
  
set /p opt=select jdk version:
  
if %opt%==7 ( 
  
  start  /I /WAIT /B wmic ENVIRONMENT where name='JAVA_HOME' set VariableValue="%JAVA_HOME_1_7%" >nul 
  
rem reg add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerEnvironment" /v JAVA_HOME /t reg_sz /d "%JAVA_HOME_1_7%" /f
  
 reg add "HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment" /v CurrentVersion /t reg_sz /d 1.7 /f    
  
 copy %JAVA_HOME_1_7%binjava.exe %windir%system32java.exe    
  
 copy %JAVA_HOME_1_7%binjavaw.exe %windir%system32javaw.exe    
  
 copy %JAVA_HOME_1_7%binjavaws.exe %windir%system32javaws.exe
  
  goto success 
  
) 
  
if %opt%==6 ( 
  
    start /I /WAIT /B wmic ENVIRONMENT where name='JAVA_HOME' set VariableValue="%JAVA_HOME_1_6%" >nul 
  
rem reg add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerEnvironment" /v JAVA_HOME /t reg_sz /d "%JAVA_HOME_1_6%" /f      
  
 reg add "HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment" /v CurrentVersion /t reg_sz /d 1.6 /f    
  
 copy %JAVA_HOME_1_6%binjava.exe %windir%system32java.exe    
  
 copy %JAVA_HOME_1_6%binjavaw.exe %windir%system32javaw.exe    
  
 copy %JAVA_HOME_1_6%binjavaws.exe %windir%system32javaws.exe
  
    goto success 
  
) 
  
echo error version, check again！ 
  
PAUSE 
  
goto start 
  
   
  
:success 
  
echo. 
  
echo success, done.
  
PAUSE