小编Bob*_*hel的帖子

如何获得java版本,并希望从批处理文件中获取java版本的'6'.我试过下面的脚本,但它没有用.

    REM check java exists using JAVA_HOME system variable

if "%JAVA_HOME%" == "" (
ECHO Installing java
start /w jdk.exe /s
SETX -m JAVA_HOME "C:\Program Files\Java\jdk1.6.0_31"
ECHO java installed successfully
) ELSE (
ECHO checking java version
goto check_java_version
)

REM check java version using JAVA_HOME system variable
:check_java_version
set PATH=%PATH%;%JAVA_HOME%\bin
for /f tokens^=2-5^ delims^=.-_^" %%j in ('%JAVA_HOME%/bin/java -version 2^>^&1') do set "jver=%%j%%k%%l%%m"
echo %jver%

JAVA_HOME具有"C:\ Program Files\Java\jdk1.6.0_31"值.

for /F %%i in ('dir /b "C:\Program Files\Apache folder\*.*"') do (
   echo Folder is NON empty
   goto launch_app
)

• 如何检查文件夹是空的？

  我试过上面的命令,但它没有用.

我在servlet中设置会话变量,并希望在javascript中访问该变量.

 ps = con.prepareStatement("select * from USERDETAILS where username=? and password=?");
 ps.setString(1, username);
 session.setAttribute("userName", username);

我在javascript函数中试过这些.但它不起作用......

var name = ${userName};
var name = '<%= Session["userName"] %>';

• 我有两个批处理文件.first.bat和test.bat

first.bat:

 @echo off

SET START="C:\Users\Neonous\Desktop\test.bat"

call %START% "C:\Program Files\Apache\Tomcat_6"

test.bat的:

 @echo off
 set "%CATALINA_HOME%=%~1"
 echo %CATALINA_HOME%

实际上我正在尝试的是,只想通过在first.bat文件中调用带有一个参数的test.bat来为该会话设置CATALINA_HOME值(不是永久性的).错误:命令的语法不正确

怎么弄这个？