检查系统中是否存在 Java 主目录并检查 Java 版本的批处理脚本

Question

有没有办法编写一个批处理脚本来检查环境中是否存在java home并检查java版本是否高于7

@echo off
IF "%JAVA_HOME%" == "" (
    echo Enter path to JAVA_HOME: 
    set /p JAVA_HOME=
) ELSE (
    echo %JAVA_HOME%
)

我使用上面的脚本来检查java home。但是它没有给出任何正确的输出

Answer 1

编辑 2017/11/16 以适应 new JRE registry location。行下的原始答案

@echo off 
    setlocal enableextensions disabledelayedexpansion

    :: for variables
    ::    %%L = possible locations under HKLM\SOFTWARE of JavaSoft registry data
    ::          note: the list includes native and redirected locations
    ::    %%J = possible locations under %%L where to find the JRE information
    ::          note: the list is sorted from newer to older locations
    ::    %%k = The generated JRE root key to check
    ::    %%v = current java version
    ::    %%e = path to java    

    for %%L in ( 
        "" "Wow6432Node\" 
    ) do for %%J in ( 
        "JRE" "Java Runtime Environment"
    ) do if not defined javaDir (
        for %%k in (
            "HKLM\SOFTWARE\%%~LJavaSoft\%%~J"
        ) do for /f "tokens=3" %%v in (
            'reg query "%%~k" /v "CurrentVersion" 2^>nul ^| find /i "CurrentVersion"'
        ) do for /f "tokens=2,*" %%d in (
            'reg query "%%~k\%%v" /v "JavaHome"   2^>nul ^| find /i "JavaHome"'
        ) do ( set "javaDir=%%~e" & set "javaVersion=%%v" )
    )

    if not defined javaDir (
        echo Java not found
    ) else (
        echo JAVA_HOME="%javaDir%"
        echo JAVA_VERSION="%javaVersion%"
    )

    pause

---

原答案

if defined JAVA_HOME (
    echo JAVA_HOME="%JAVA_HOME%"
) else (
    echo JAVA_HOME is not defined 
)

但这不会告诉你（也不会询问用户）是否安装了 java 或它是什么版本。

如果安装了java，你可以询问windows（它存储在注册表中）它在哪里以及你有什么版本

@echo off 
    setlocal enableextensions disabledelayedexpansion

    :: possible locations under HKLM\SOFTWARE of JavaSoft registry data
    set "javaNativeVersion="
    set "java32ON64=Wow6432Node\"

    :: for variables
    ::    %%k = HKLM\SOFTWARE subkeys where to search for JavaSoft key
    ::    %%j = full path of "Java Runtime Environment" key under %%k
    ::    %%v = current java version
    ::    %%e = path to java

    set "javaDir="
    set "javaVersion="
    for %%k in ( "%javaNativeVersion%" "%java32ON64%") do if not defined javaDir (
        for %%j in (
            "HKLM\SOFTWARE\%%~kJavaSoft\Java Runtime Environment"
        ) do for /f "tokens=3" %%v in (
            'reg query "%%~j" /v "CurrentVersion" 2^>nul ^| find /i "CurrentVersion"'
        ) do for /f "tokens=2,*" %%d in (
            'reg query "%%~j\%%v" /v "JavaHome"   2^>nul ^| find /i "JavaHome"'
        ) do ( set "javaDir=%%~e" & set "javaVersion=%%v" )
    )

    if not defined javaDir (
        echo Java not found
    ) else (
        echo JAVA_HOME="%javaDir%"
        echo JAVA_VERSION="%javaVersion%"
    )

    endlocal
    pause