推薦的JDK版本組合：

?? 主力版本：
- JDK 17 (LTS) - 當(dāng)前主流長期支持版本
- JDK 11 (LTS) - 企業(yè)級應(yīng)用廣泛使用
- JDK 8 (LTS) - 歷史項(xiàng)目維護(hù)必備

?? 嘗鮮版本：
- JDK 21 (LTS) - 最新長期支持版本
- JDK 22 - 最新特性體驗(yàn)

?? 特殊需求：
- JDK 1.7 - 極老項(xiàng)目維護(hù)
- OpenJDK - 開源項(xiàng)目偏好

C:\Program Files\Java\
├── jdk-8\                    # JDK 8
├── jdk-11\                   # JDK 11  
├── jdk-17\                   # JDK 17
├── jdk-21\                   # JDK 21
└── current -> jdk-17\        # 當(dāng)前使用版本的符號鏈接

# 1. 訪問Oracle官網(wǎng)下載
# https://www.oracle.com/java/technologies/downloads/

# 2. 選擇對應(yīng)版本的Windows x64 Installer
# 例如：jdk-17_windows-x64_bin.exe

# 3. 安裝時自定義安裝路徑
# 默認(rèn)路徑：C:\Program Files\Java\jdk-17
# 建議路徑：C:\Java\jdk-17 (避免空格路徑問題)

# 使用Chocolatey包管理器安裝（推薦）
# 1. 安裝Chocolatey
Set-ExecutionPolicy Bypass -Scope Process -Force
[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072
iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))

# 2. 安裝多個OpenJDK版本
choco install openjdk8 -y
choco install openjdk11 -y  
choco install openjdk17 -y
choco install openjdk21 -y

# 3. 查看安裝的版本
choco list openjdk -l

# 創(chuàng)建Java安裝目錄
New-Item -ItemType Directory -Path "C:\Java" -Force

# 下載并解壓OpenJDK（以JDK 17為例）
# 1. 從 https://adoptium.net/ 下載zip包
# 2. 解壓到 C:\Java\jdk-17

# 驗(yàn)證安裝
C:\Java\jdk-17\bin\java -version

# check_jdk_installations.ps1
Write-Host "=== JDK Installation Check ===" -ForegroundColor Green

$jdkPaths = @(
    "C:\Java\jdk-8",
    "C:\Java\jdk-11", 
    "C:\Java\jdk-17",
    "C:\Java\jdk-21",
    "C:\Program Files\Java\jdk-8",
    "C:\Program Files\Java\jdk-11",
    "C:\Program Files\Java\jdk-17",
    "C:\Program Files\Java\jdk-21"
)

foreach ($path in $jdkPaths) {
    if (Test-Path "$path\bin\java.exe") {
        Write-Host "? Found JDK at: $path" -ForegroundColor Green
        
        # 獲取版本信息
        $version = & "$path\bin\java.exe" -version 2>&1 | Select-String "version" | Select-Object -First 1
        Write-Host "   Version: $version" -ForegroundColor Cyan
        Write-Host ""
    }
}

Write-Host "Current JAVA_HOME: $env:JAVA_HOME" -ForegroundColor Yellow
Write-Host "Current PATH Java: $(where.exe java)" -ForegroundColor Yellow

方法一：通過系統(tǒng)屬性
1. 右鍵"此電腦" → "屬性"
2. 點(diǎn)擊"高級系統(tǒng)設(shè)置"
3. 點(diǎn)擊"環(huán)境變量"按鈕

方法二：通過運(yùn)行命令
1. Win + R 打開運(yùn)行對話框
2. 輸入：sysdm.cpl
3. 切換到"高級"選項(xiàng)卡
4. 點(diǎn)擊"環(huán)境變量"

方法三：通過設(shè)置應(yīng)用
1. Win + I 打開設(shè)置
2. 搜索"環(huán)境變量"
3. 點(diǎn)擊"編輯系統(tǒng)環(huán)境變量"

在"系統(tǒng)變量"區(qū)域：
1. 點(diǎn)擊"新建"按鈕
2. 變量名：JAVA_HOME
3. 變量值：C:\Java\jdk-17
4. 點(diǎn)擊"確定"

注意事項(xiàng)：
- 路徑不要包含分號
- 路徑末尾不要加反斜杠
- 如果路徑包含空格，需要用雙引號包圍

在"系統(tǒng)變量"區(qū)域找到PATH：
1. 選中"Path"變量，點(diǎn)擊"編輯"
2. 點(diǎn)擊"新建"按鈕
3. 輸入：%JAVA_HOME%\bin
4. 點(diǎn)擊"確定"
或者在變量值末尾添加：
;%JAVA_HOME%\bin
注意：
- 使用%JAVA_HOME%引用，便于后續(xù)切換
- 確保%JAVA_HOME%\bin在其他Java路徑之前

# 重新打開命令提示符窗口
# 驗(yàn)證JAVA_HOME
echo %JAVA_HOME%

# 驗(yàn)證PATH中的Java
where java

# 驗(yàn)證Java版本
java -version

# 驗(yàn)證編譯器版本
javac -version

# 完整驗(yàn)證腳本
# ?? 實(shí)用技巧：保存為verify_java.bat，用于快速驗(yàn)證Java環(huán)境配置
@echo off
echo === Java Environment Verification ===
echo.
echo JAVA_HOME: %JAVA_HOME%
echo.
echo Java executable location:
where java
echo.
echo Java version:
java -version
echo.
echo Java compiler version:
javac -version
echo.
echo === Verification Complete ===
pause

1. 打開環(huán)境變量設(shè)置
2. 修改JAVA_HOME的值為目標(biāo)JDK路徑
   例如：C:\Java\jdk-11
3. 點(diǎn)擊"確定"保存
4. 重新打開命令提示符驗(yàn)證

# 查看當(dāng)前用戶的Java環(huán)境
[Environment]::GetEnvironmentVariable("JAVA_HOME", "User")
[Environment]::GetEnvironmentVariable("PATH", "User")

# 查看系統(tǒng)級的Java環(huán)境  
[Environment]::GetEnvironmentVariable("JAVA_HOME", "Machine")
[Environment]::GetEnvironmentVariable("PATH", "Machine")

@echo off
REM switch_jdk.bat - JDK版本切換腳本
REM ?? 重點(diǎn)提示：這是最基礎(chǔ)的JDK切換腳本，適合快速上手

echo === JDK Version Switcher ===
echo.
echo Available JDK versions:
echo 1. JDK 8
echo 2. JDK 11  
echo 3. JDK 17
echo 4. JDK 21
echo 5. Show current version
echo 0. Exit
echo.

set /p choice="Please select JDK version (0-5): "

if "%choice%"=="1" goto JDK8
if "%choice%"=="2" goto JDK11
if "%choice%"=="3" goto JDK17
if "%choice%"=="4" goto JDK21
if "%choice%"=="5" goto SHOW
if "%choice%"=="0" goto EXIT
goto INVALID

:JDK8
set JAVA_HOME=C:\Java\jdk-8
echo Switched to JDK 8
goto VERIFY

:JDK11
set JAVA_HOME=C:\Java\jdk-11
echo Switched to JDK 11
goto VERIFY

:JDK17
set JAVA_HOME=C:\Java\jdk-17
echo Switched to JDK 17
goto VERIFY

:JDK21
set JAVA_HOME=C:\Java\jdk-21
echo Switched to JDK 21
goto VERIFY

:SHOW
echo Current JAVA_HOME: %JAVA_HOME%
"%JAVA_HOME%\bin\java" -version
goto END

:VERIFY
echo.
echo New JAVA_HOME: %JAVA_HOME%
echo Verifying installation...
"%JAVA_HOME%\bin\java" -version
goto END

:INVALID
echo Invalid choice! Please try again.
goto END

:EXIT
echo Goodbye!
exit /b 0

:END
echo.
pause

@echo off
REM advanced_jdk_switch.bat - 高級JDK切換腳本
REM ?? 實(shí)用技巧：這個腳本包含日志記錄、歷史查看、永久設(shè)置等高級功能
setlocal enabledelayedexpansion

REM 配置JDK安裝路徑
set JDK_BASE_PATH=C:\Java
set JDK8_PATH=%JDK_BASE_PATH%\jdk-8
set JDK11_PATH=%JDK_BASE_PATH%\jdk-11
set JDK17_PATH=%JDK_BASE_PATH%\jdk-17
set JDK21_PATH=%JDK_BASE_PATH%\jdk-21

REM 日志文件
set LOG_FILE=%~dp0jdk_switch.log

:MAIN
cls
echo ╔══════════════════════════════════════╗
echo ║        JDK Version Manager           ║
echo ╚══════════════════════════════════════╝
echo.

REM 檢查當(dāng)前JDK版本
call :CHECK_CURRENT

echo Available operations:
echo [1] Switch to JDK 8
echo [2] Switch to JDK 11
echo [3] Switch to JDK 17
echo [4] Switch to JDK 21
echo [5] List all installed JDKs
echo [6] Verify current installation
echo [7] Set JAVA_HOME permanently
echo [8] View switch history
echo [0] Exit
echo.

set /p "choice=Select option (0-8): "

if "%choice%"=="1" call :SWITCH_JDK "8" "%JDK8_PATH%"
if "%choice%"=="2" call :SWITCH_JDK "11" "%JDK11_PATH%"
if "%choice%"=="3" call :SWITCH_JDK "17" "%JDK17_PATH%"
if "%choice%"=="4" call :SWITCH_JDK "21" "%JDK21_PATH%"
if "%choice%"=="5" call :LIST_JDKS
if "%choice%"=="6" call :VERIFY_INSTALLATION
if "%choice%"=="7" call :SET_PERMANENT
if "%choice%"=="8" call :SHOW_HISTORY
if "%choice%"=="0" goto :EXIT

echo.
pause
goto :MAIN

REM 檢查當(dāng)前JDK版本
:CHECK_CURRENT
echo Current Status:
if defined JAVA_HOME (
    echo JAVA_HOME: %JAVA_HOME%
    if exist "%JAVA_HOME%\bin\java.exe" (
        for /f "tokens=3" %%a in ('"%JAVA_HOME%\bin\java" -version 2^>^&1 ^| findstr "version"') do (
            set CURRENT_VERSION=%%a
            set CURRENT_VERSION=!CURRENT_VERSION:"=!
        )
        echo Current Version: !CURRENT_VERSION!
    ) else (
        echo ? JAVA_HOME points to invalid path
    )
) else (
    echo ? JAVA_HOME not set
)
echo ----------------------------------------
return

REM 切換JDK版本
:SWITCH_JDK
set JDK_VERSION=%~1
set JDK_PATH=%~2

echo.
echo Switching to JDK %JDK_VERSION%...

REM 檢查JDK是否存在
if not exist "%JDK_PATH%\bin\java.exe" (
    echo ? JDK %JDK_VERSION% not found at: %JDK_PATH%
    echo Please install JDK %JDK_VERSION% first.
    return
)

REM 設(shè)置環(huán)境變量
set JAVA_HOME=%JDK_PATH%
set PATH=%JAVA_HOME%\bin;%PATH%

REM 驗(yàn)證切換結(jié)果
echo ? Successfully switched to JDK %JDK_VERSION%
echo New JAVA_HOME: %JAVA_HOME%
echo.

REM 顯示版本信息
"%JAVA_HOME%\bin\java" -version

REM 記錄切換歷史
echo [%date% %time%] Switched to JDK %JDK_VERSION% at %JDK_PATH% >> "%LOG_FILE%"

return

REM 列出所有已安裝的JDK
:LIST_JDKS
echo.
echo ═══ Installed JDK Versions ═══

set JDK_FOUND=0

if exist "%JDK8_PATH%\bin\java.exe" (
    echo ? JDK 8  - %JDK8_PATH%
    set /a JDK_FOUND+=1
)

if exist "%JDK11_PATH%\bin\java.exe" (
    echo ? JDK 11 - %JDK11_PATH%
    set /a JDK_FOUND+=1
)

if exist "%JDK17_PATH%\bin\java.exe" (
    echo ? JDK 17 - %JDK17_PATH%
    set /a JDK_FOUND+=1
)

if exist "%JDK21_PATH%\bin\java.exe" (
    echo ? JDK 21 - %JDK21_PATH%
    set /a JDK_FOUND+=1
)

if %JDK_FOUND%==0 (
    echo ? No JDK installations found
    echo Please install JDK versions in: %JDK_BASE_PATH%
)

echo.
echo Total JDK versions found: %JDK_FOUND%
return

REM 驗(yàn)證當(dāng)前安裝
:VERIFY_INSTALLATION
echo.
echo ═══ Installation Verification ═══

if not defined JAVA_HOME (
    echo ? JAVA_HOME is not set
    return
)

echo JAVA_HOME: %JAVA_HOME%

if not exist "%JAVA_HOME%\bin\java.exe" (
    echo ? java.exe not found
    return
)

if not exist "%JAVA_HOME%\bin\javac.exe" (
    echo ? javac.exe not found
    return
)

echo ? Java Runtime:
"%JAVA_HOME%\bin\java" -version

echo.
echo ? Java Compiler:
"%JAVA_HOME%\bin\javac" -version

echo.
echo ? Installation verification passed!
return

REM 永久設(shè)置JAVA_HOME
:SET_PERMANENT
echo.
echo ═══ Set JAVA_HOME Permanently ═══
echo.
echo This will set JAVA_HOME in system environment variables.
echo Current session JAVA_HOME: %JAVA_HOME%
echo.
set /p "confirm=Make this permanent? (y/n): "

if /i "%confirm%"=="y" (
    echo Setting JAVA_HOME permanently...
    setx JAVA_HOME "%JAVA_HOME%" /M >nul 2>&1
    if errorlevel 1 (
        echo ? Failed to set system variable. Try running as Administrator.
        setx JAVA_HOME "%JAVA_HOME%" >nul 2>&1
        if errorlevel 1 (
            echo ? Failed to set user variable as well.
        ) else (
            echo ? Set JAVA_HOME for current user only.
        )
    ) else (
        echo ? JAVA_HOME set permanently for all users.
    )
) else (
    echo Operation cancelled.
)

return

REM 顯示切換歷史
:SHOW_HISTORY
echo.
echo ═══ JDK Switch History ═══

if exist "%LOG_FILE%" (
    type "%LOG_FILE%"
) else (
    echo No switch history found.
)

return

:EXIT
echo.
echo Thanks for using JDK Version Manager!
exit /b 0

REM create_shortcut.bat - 創(chuàng)建桌面快捷方式
@echo off

set SCRIPT_PATH=%~dp0advanced_jdk_switch.bat
set SHORTCUT_PATH=%USERPROFILE%\Desktop\JDK Switcher.lnk

REM 使用PowerShell創(chuàng)建快捷方式
powershell -Command "& {$WshShell = New-Object -comObject WScript.Shell; $Shortcut = $WshShell.CreateShortcut('%SHORTCUT_PATH%'); $Shortcut.TargetPath = '%SCRIPT_PATH%'; $Shortcut.WorkingDirectory = '%~dp0'; $Shortcut.IconLocation = 'C:\Windows\System32\cmd.exe,0'; $Shortcut.Description = 'JDK Version Switcher'; $Shortcut.Save()}"

echo Desktop shortcut created: %SHORTCUT_PATH%
pause

REM project_jdk.bat - 項(xiàng)目級JDK配置
REM ?? 重點(diǎn)提示：將此腳本放在項(xiàng)目根目錄，配合.jdkversion文件使用
@echo off

REM 檢查項(xiàng)目配置文件
if exist ".jdkversion" (
    set /p PROJECT_JDK=<.jdkversion
    echo Found project JDK configuration: %PROJECT_JDK%
    
    REM 根據(jù)配置設(shè)置JDK
    if "%PROJECT_JDK%"=="8" set JAVA_HOME=C:\Java\jdk-8
    if "%PROJECT_JDK%"=="11" set JAVA_HOME=C:\Java\jdk-11
    if "%PROJECT_JDK%"=="17" set JAVA_HOME=C:\Java\jdk-17
    if "%PROJECT_JDK%"=="21" set JAVA_HOME=C:\Java\jdk-21
    
    set PATH=%JAVA_HOME%\bin;%PATH%
    
    echo Project JDK set to: %JAVA_HOME%
    java -version
) else (
    echo No .jdkversion file found in current directory
    echo Create .jdkversion file with content: 8, 11, 17, or 21
)

REM 啟動項(xiàng)目開發(fā)環(huán)境
if exist "pom.xml" (
    echo Maven project detected
    mvn --version
) else if exist "build.gradle" (
    echo Gradle project detected  
    gradle --version
) else if exist "build.sbt" (
    echo SBT project detected
    sbt about
)

cmd /k

17

# JDKManager.ps1 - PowerShell JDK版本管理器
# ?? 重點(diǎn)提示：這是功能最完整的JDK管理器，支持命令行參數(shù)和交互式菜單
param(
    [string]$Action = "menu",
    [string]$Version = "",
    [switch]$List,
    [switch]$Current,
    [switch]$Install,
    [switch]$Remove,
    [switch]$Permanent,
    [switch]$Help
)

# 配置參數(shù)
$JDK_BASE_PATH = "C:\Java"
$CONFIG_FILE = "$env:USERPROFILE\.jdkmanager.json"
$LOG_FILE = "$env:USERPROFILE\.jdkmanager.log"

# JDK版本配置
$JDK_VERSIONS = @{
    "8" = @{
        "Path" = "$JDK_BASE_PATH\jdk-8"
        "Name" = "Oracle JDK 8"
        "LTS" = $true
    }
    "11" = @{
        "Path" = "$JDK_BASE_PATH\jdk-11"
        "Name" = "Oracle JDK 11"
        "LTS" = $true
    }
    "17" = @{
        "Path" = "$JDK_BASE_PATH\jdk-17"
        "Name" = "Oracle JDK 17"
        "LTS" = $true
    }
    "21" = @{
        "Path" = "$JDK_BASE_PATH\jdk-21"
        "Name" = "Oracle JDK 21"
        "LTS" = $true
    }
}

# 日志函數(shù)
function Write-Log {
    param([string]$Message, [string]$Level = "INFO")
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $logEntry = "[$timestamp] [$Level] $Message"
    Add-Content -Path $LOG_FILE -Value $logEntry
    
    switch ($Level) {
        "ERROR" { Write-Host $logEntry -ForegroundColor Red }
        "WARN" { Write-Host $logEntry -ForegroundColor Yellow }
        "SUCCESS" { Write-Host $logEntry -ForegroundColor Green }
        default { Write-Host $logEntry -ForegroundColor White }
    }
}

# 檢查JDK是否已安裝
function Test-JDKInstallation {
    param([string]$JDKPath)
    
    return (Test-Path "$JDKPath\bin\java.exe") -and (Test-Path "$JDKPath\bin\javac.exe")
}

# 獲取JDK版本信息
function Get-JDKVersion {
    param([string]$JDKPath)
    
    if (Test-JDKInstallation -JDKPath $JDKPath) {
        try {
            $versionOutput = & "$JDKPath\bin\java.exe" -version 2>&1
            $versionLine = $versionOutput | Select-String "version" | Select-Object -First 1
            return $versionLine.ToString()
        }
        catch {
            return "Unknown version"
        }
    }
    return "Not installed"
}

# 列出所有JDK版本
function Show-JDKList {
    Write-Host "`n═══ Installed JDK Versions ═══" -ForegroundColor Cyan
    
    $installedCount = 0
    foreach ($version in $JDK_VERSIONS.Keys | Sort-Object) {
        $jdkInfo = $JDK_VERSIONS[$version]
        $isInstalled = Test-JDKInstallation -JDKPath $jdkInfo.Path
        
        if ($isInstalled) {
            $versionInfo = Get-JDKVersion -JDKPath $jdkInfo.Path
            $ltsTag = if ($jdkInfo.LTS) { " (LTS)" } else { "" }
            Write-Host "? JDK $version$ltsTag - $($jdkInfo.Path)" -ForegroundColor Green
            Write-Host "   $versionInfo" -ForegroundColor Gray
            $installedCount++
        } else {
            Write-Host "? JDK $version - Not installed" -ForegroundColor Red
        }
    }
    
    Write-Host "`nTotal installed: $installedCount" -ForegroundColor Yellow
}

# 顯示當(dāng)前JDK狀態(tài)
function Show-CurrentJDK {
    Write-Host "`n═══ Current JDK Status ═══" -ForegroundColor Cyan
    
    if ($env:JAVA_HOME) {
        Write-Host "JAVA_HOME: $env:JAVA_HOME" -ForegroundColor Green
        
        if (Test-JDKInstallation -JDKPath $env:JAVA_HOME) {
            $versionInfo = Get-JDKVersion -JDKPath $env:JAVA_HOME
            Write-Host "Version: $versionInfo" -ForegroundColor Green
        } else {
            Write-Host "? JAVA_HOME points to invalid JDK installation" -ForegroundColor Red
        }
    } else {
        Write-Host "? JAVA_HOME is not set" -ForegroundColor Red
    }
    
    # 檢查PATH中的Java
    $javaInPath = Get-Command java -ErrorAction SilentlyContinue
    if ($javaInPath) {
        Write-Host "Java in PATH: $($javaInPath.Source)" -ForegroundColor Green
    } else {
        Write-Host "? Java not found in PATH" -ForegroundColor Red
    }
}

# 切換JDK版本
function Switch-JDK {
    param([string]$TargetVersion)
    
    if (-not $JDK_VERSIONS.ContainsKey($TargetVersion)) {
        Write-Log "Invalid JDK version: $TargetVersion" "ERROR"
        Write-Host "Available versions: $($JDK_VERSIONS.Keys -join ', ')" -ForegroundColor Yellow
        return $false
    }
    
    $jdkInfo = $JDK_VERSIONS[$TargetVersion]
    
    if (-not (Test-JDKInstallation -JDKPath $jdkInfo.Path)) {
        Write-Log "JDK $TargetVersion is not installed at $($jdkInfo.Path)" "ERROR"
        return $false
    }
    
    # 設(shè)置環(huán)境變量
    $env:JAVA_HOME = $jdkInfo.Path
    $env:PATH = "$($jdkInfo.Path)\bin;" + ($env:PATH -replace [regex]::Escape("$($jdkInfo.Path)\bin;"), "")
    
    Write-Log "Switched to JDK $TargetVersion at $($jdkInfo.Path)" "SUCCESS"
    
    # 顯示版本信息
    & "$($jdkInfo.Path)\bin\java.exe" -version
    
    # 保存當(dāng)前配置
    Save-Configuration -CurrentVersion $TargetVersion
    
    return $true
}

# 永久設(shè)置JAVA_HOME
function Set-PermanentJavaHome {
    param([string]$JDKPath)
    
    try {
        # 嘗試設(shè)置系統(tǒng)環(huán)境變量
        [Environment]::SetEnvironmentVariable("JAVA_HOME", $JDKPath, "Machine")
        Write-Log "JAVA_HOME set permanently for all users" "SUCCESS"
        return $true
    }
    catch {
        try {
            # 設(shè)置用戶環(huán)境變量
            [Environment]::SetEnvironmentVariable("JAVA_HOME", $JDKPath, "User")
            Write-Log "JAVA_HOME set permanently for current user" "SUCCESS"
            return $true
        }
        catch {
            Write-Log "Failed to set JAVA_HOME permanently: $($_.Exception.Message)" "ERROR"
            return $false
        }
    }
}

# 保存配置
function Save-Configuration {
    param([string]$CurrentVersion)
    
    $config = @{
        "LastUsed" = $CurrentVersion
        "LastUpdate" = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
        "JDKBasePath" = $JDK_BASE_PATH
    }
    
    $config | ConvertTo-Json | Set-Content -Path $CONFIG_FILE
}

# 加載配置
function Load-Configuration {
    if (Test-Path $CONFIG_FILE) {
        try {
            return Get-Content -Path $CONFIG_FILE | ConvertFrom-Json
        }
        catch {
            Write-Log "Failed to load configuration: $($_.Exception.Message)" "WARN"
        }
    }
    return $null
}

# 自動檢測已安裝的JDK
function Find-InstalledJDKs {
    Write-Host "`n?? Scanning for JDK installations..." -ForegroundColor Cyan
    
    $commonPaths = @(
        "C:\Program Files\Java",
        "C:\Program Files (x86)\Java",
        "C:\Java",
        "C:\jdk*",
        "$env:USERPROFILE\Java"
    )
    
    $foundJDKs = @()
    
    foreach ($basePath in $commonPaths) {
        if (Test-Path $basePath) {
            $jdkDirs = Get-ChildItem -Path $basePath -Directory | Where-Object { $_.Name -match "jdk" }
            
            foreach ($dir in $jdkDirs) {
                if (Test-JDKInstallation -JDKPath $dir.FullName) {
                    $version = Get-JDKVersion -JDKPath $dir.FullName
                    $foundJDKs += @{
                        "Path" = $dir.FullName
                        "Version" = $version
                        "Name" = $dir.Name
                    }
                }
            }
        }
    }
    
    if ($foundJDKs.Count -gt 0) {
        Write-Host "`n? Found $($foundJDKs.Count) JDK installation(s):" -ForegroundColor Green
        foreach ($jdk in $foundJDKs) {
            Write-Host "   $($jdk.Name) - $($jdk.Path)" -ForegroundColor White
            Write-Host "   $($jdk.Version)" -ForegroundColor Gray
        }
    } else {
        Write-Host "`n? No JDK installations found" -ForegroundColor Red
    }
    
    return $foundJDKs
}

# 顯示幫助信息
function Show-Help {
    Write-Host @"
JDK Manager for Windows - PowerShell Edition

USAGE:
    .\JDKManager.ps1 [OPTIONS]

OPTIONS:
    -Action <action>    Action to perform (menu, switch, list, current, scan)
    -Version <version>  JDK version to switch to (8, 11, 17, 21)
    -List              List all configured JDK versions
    -Current           Show current JDK status
    -Install           Install JDK (interactive)
    -Remove            Remove JDK configuration
    -Permanent         Set JAVA_HOME permanently
    -Help              Show this help message

EXAMPLES:
    .\JDKManager.ps1                    # Show interactive menu
    .\JDKManager.ps1 -Action switch -Version 17    # Switch to JDK 17
    .\JDKManager.ps1 -List              # List all JDK versions
    .\JDKManager.ps1 -Current           # Show current JDK
    .\JDKManager.ps1 -Action scan       # Scan for JDK installations

CONFIGURATION:
    Config file: $CONFIG_FILE
    Log file: $LOG_FILE
    JDK base path: $JDK_BASE_PATH
"@ -ForegroundColor Green
}

# 交互式菜單
function Show-InteractiveMenu {
    do {
        Clear-Host
        Write-Host "╔══════════════════════════════════════╗" -ForegroundColor Cyan
        Write-Host "║        JDK Version Manager           ║" -ForegroundColor Cyan
        Write-Host "║         PowerShell Edition           ║" -ForegroundColor Cyan
        Write-Host "╚══════════════════════════════════════╝" -ForegroundColor Cyan
        Write-Host ""
        
        # 顯示當(dāng)前狀態(tài)
        Show-CurrentJDK
        
        Write-Host "`n?? Available Actions:" -ForegroundColor Yellow
        Write-Host "[1] Switch JDK Version" -ForegroundColor White
        Write-Host "[2] List All JDK Versions" -ForegroundColor White
        Write-Host "[3] Scan for JDK Installations" -ForegroundColor White
        Write-Host "[4] Set JAVA_HOME Permanently" -ForegroundColor White
        Write-Host "[5] View Switch History" -ForegroundColor White
        Write-Host "[6] Configuration Management" -ForegroundColor White
        Write-Host "[7] Help" -ForegroundColor White
        Write-Host "[0] Exit" -ForegroundColor Red
        Write-Host ""
        
        $choice = Read-Host "Select option (0-7)"
        
        switch ($choice) {
            "1" {
                Write-Host "`nAvailable JDK versions:" -ForegroundColor Yellow
                foreach ($version in $JDK_VERSIONS.Keys | Sort-Object) {
                    $isInstalled = Test-JDKInstallation -JDKPath $JDK_VERSIONS[$version].Path
                    $status = if ($isInstalled) { "?" } else { "?" }
                    Write-Host "$status JDK $version" -ForegroundColor White
                }
                
                $targetVersion = Read-Host "`nEnter JDK version to switch to"
                if ($targetVersion) {
                    Switch-JDK -TargetVersion $targetVersion
                    Read-Host "`nPress Enter to continue"
                }
            }
            "2" {
                Show-JDKList
                Read-Host "`nPress Enter to continue"
            }
            "3" {
                Find-InstalledJDKs
                Read-Host "`nPress Enter to continue"
            }
            "4" {
                if ($env:JAVA_HOME) {
                    Write-Host "`nCurrent JAVA_HOME: $env:JAVA_HOME" -ForegroundColor Green
                    $confirm = Read-Host "Set this as permanent JAVA_HOME? (y/n)"
                    if ($confirm -eq "y" -or $confirm -eq "Y") {
                        Set-PermanentJavaHome -JDKPath $env:JAVA_HOME
                    }
                } else {
                    Write-Host "`n? JAVA_HOME is not set. Please switch to a JDK version first." -ForegroundColor Red
                }
                Read-Host "`nPress Enter to continue"
            }
            "5" {
                if (Test-Path $LOG_FILE) {
                    Write-Host "`n═══ Switch History ═══" -ForegroundColor Cyan
                    Get-Content $LOG_FILE | Select-Object -Last 20
                } else {
                    Write-Host "`n? No history found" -ForegroundColor Red
                }
                Read-Host "`nPress Enter to continue"
            }
            "6" {
                Write-Host "`n═══ Configuration ═══" -ForegroundColor Cyan
                Write-Host "Config file: $CONFIG_FILE" -ForegroundColor White
                Write-Host "Log file: $LOG_FILE" -ForegroundColor White
                Write-Host "JDK base path: $JDK_BASE_PATH" -ForegroundColor White
                
                $config = Load-Configuration
                if ($config) {
                    Write-Host "Last used: JDK $($config.LastUsed)" -ForegroundColor Green
                    Write-Host "Last update: $($config.LastUpdate)" -ForegroundColor Green
                }
                Read-Host "`nPress Enter to continue"
            }
            "7" {
                Show-Help
                Read-Host "`nPress Enter to continue"
            }
            "0" {
                Write-Host "`n?? Goodbye!" -ForegroundColor Green
                return
            }
            default {
                Write-Host "`n? Invalid option. Please try again." -ForegroundColor Red
                Start-Sleep 2
            }
        }
    } while ($true)
}

# 主執(zhí)行邏輯
function Main {
    # 創(chuàng)建必要的目錄
    if (-not (Test-Path $JDK_BASE_PATH)) {
        New-Item -ItemType Directory -Path $JDK_BASE_PATH -Force | Out-Null
    }
    
    # 處理命令行參數(shù)
    if ($Help) {
        Show-Help
        return
    }
    
    if ($List) {
        Show-JDKList
        return
    }
    
    if ($Current) {
        Show-CurrentJDK
        return
    }
    
    # 根據(jù)Action參數(shù)執(zhí)行相應(yīng)操作
    switch ($Action.ToLower()) {
        "switch" {
            if ($Version) {
                Switch-JDK -TargetVersion $Version
            } else {
                Write-Host "? Version parameter required for switch action" -ForegroundColor Red
                Show-Help
            }
        }
        "list" {
            Show-JDKList
        }
        "current" {
            Show-CurrentJDK
        }
        "scan" {
            Find-InstalledJDKs
        }
        "menu" {
            Show-InteractiveMenu
        }
        default {
            Show-InteractiveMenu
        }
    }
}

# 執(zhí)行主函數(shù)
Main

# Microsoft.PowerShell_profile.ps1
# 添加到 $PROFILE 文件中
# ?? 實(shí)用技巧：將這些函數(shù)添加到PowerShell配置文件，實(shí)現(xiàn)全局JDK管理命令

# JDK管理函數(shù)
function jdk {
    param(
        [string]$Version = "",
        [switch]$List,
        [switch]$Current
    )
    
    $JDK_MANAGER_SCRIPT = "$env:USERPROFILE\Scripts\JDKManager.ps1"
    
    if ($List) {
        & $JDK_MANAGER_SCRIPT -List
    }
    elseif ($Current) {
        & $JDK_MANAGER_SCRIPT -Current
    }
    elseif ($Version) {
        & $JDK_MANAGER_SCRIPT -Action switch -Version $Version
    }
    else {
        & $JDK_MANAGER_SCRIPT
    }
}

# JDK快捷切換函數(shù)
function jdk8 { jdk 8 }
function jdk11 { jdk 11 }
function jdk17 { jdk 17 }
function jdk21 { jdk 21 }

# 啟動時顯示當(dāng)前JDK狀態(tài)
if ($env:JAVA_HOME) {
    Write-Host "Current JDK: " -NoNewline -ForegroundColor Yellow
    Write-Host $env:JAVA_HOME -ForegroundColor Green
}

# 自動補(bǔ)全
Register-ArgumentCompleter -CommandName jdk -ParameterName Version -ScriptBlock {
    param($commandName, $parameterName, $wordToComplete, $commandAst, $fakeBoundParameters)
    
    $versions = @('8', '11', '17', '21')
    $versions | Where-Object { $_ -like "$wordToComplete*" } | ForEach-Object {
        [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_)
    }
}

# 安裝 scoop (包管理器)
# ?? 實(shí)用技巧：Scoop是Windows下的包管理器，類似于Linux的apt或yum
Set-ExecutionPolicy RemoteSigned -Scope CurrentUser
iwr -useb get.scoop.sh | iex

# 安裝 jenv
scoop bucket add java
scoop install jenv

# 添加JDK版本到j(luò)env
jenv add C:\Java\jdk-8
jenv add C:\Java\jdk-11
jenv add C:\Java\jdk-17
jenv add C:\Java\jdk-21

# 查看可用版本
jenv versions

# 設(shè)置全局JDK版本
jenv global 17

# 設(shè)置項(xiàng)目本地JDK版本
cd your-project
jenv local 11

# 查看當(dāng)前版本
jenv version

# 在WSL中安裝SDKMAN
curl -s "https://get.sdkman.io" | bash
source "$HOME/.sdkman/bin/sdkman-init.sh"

# 列出可用的Java版本
sdk list java

# 安裝多個JDK版本
sdk install java 8.0.392-tem
sdk install java 11.0.21-tem
sdk install java 17.0.9-tem
sdk install java 21.0.1-tem

# 切換JDK版本
sdk use java 17.0.9-tem

# 設(shè)置默認(rèn)版本
sdk default java 17.0.9-tem

# 查看當(dāng)前版本
sdk current java

# 安裝Chocolatey
Set-ExecutionPolicy Bypass -Scope Process -Force
[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072
iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))

# 搜索可用的JDK包
choco search jdk

# 安裝多個JDK版本
choco install openjdk8 -y
choco install openjdk11 -y
choco install openjdk17 -y
choco install openjdk21 -y

# 列出已安裝的JDK
choco list jdk -l

# 創(chuàng)建JDK切換腳本
@echo off
echo Available JDK versions:
echo 1. OpenJDK 8
echo 2. OpenJDK 11
echo 3. OpenJDK 17
echo 4. OpenJDK 21

set /p choice="Select JDK version: "

if "%choice%"=="1" (
    set JAVA_HOME=C:\Program Files\Eclipse Adoptium\jdk-8.0.392.8-hotspot
) else if "%choice%"=="2" (
    set JAVA_HOME=C:\Program Files\Eclipse Adoptium\jdk-11.0.21.9-hotspot
) else if "%choice%"=="3" (
    set JAVA_HOME=C:\Program Files\Eclipse Adoptium\jdk-17.0.9.9-hotspot
) else if "%choice%"=="4" (
    set JAVA_HOME=C:\Program Files\Eclipse Adoptium\jdk-21.0.1.12-hotspot
)

set PATH=%JAVA_HOME%\bin;%PATH%
echo Switched to: %JAVA_HOME%
java -version

1. 打開 File → Project Structure
2. 在 Platform Settings → SDKs 中添加JDK
3. 點(diǎn)擊 + 號，選擇 Add JDK
4. 瀏覽到JDK安裝目錄，例如：C:\Java\jdk-17
5. 重命名為便于識別的名稱，如 "JDK 17"
6. 重復(fù)步驟添加其他JDK版本

1. 打開 File → Project Structure
2. 在 Project Settings → Project 中
3. 設(shè)置 Project SDK 為所需的JDK版本
4. 設(shè)置 Project language level 對應(yīng)JDK版本
5. 點(diǎn)擊 Apply 和 OK 保存設(shè)置

1. 打開 File → Project Structure
2. 在 Project Settings → Modules 中
3. 選擇要配置的模塊
4. 在 Dependencies 選項(xiàng)卡中
5. 設(shè)置 Module SDK 為特定JDK版本

1. 打開 Window → Preferences
2. 導(dǎo)航到 Java → Installed JREs
3. 點(diǎn)擊 Add 按鈕
4. 選擇 Standard VM，點(diǎn)擊 Next
5. 在 JRE home 中瀏覽到JDK目錄
6. JRE name 設(shè)置為識別名稱，如 "JDK 17"
7. 點(diǎn)擊 Finish 完成添加

1. 在 Installed JREs 列表中
2. 勾選要設(shè)為默認(rèn)的JDK版本
3. 點(diǎn)擊 Apply and Close

1. 右鍵項(xiàng)目 → Properties
2. 選擇 Java Build Path
3. 在 Libraries 選項(xiàng)卡中
4. 展開 Modulepath 或 Classpath
5. 選擇 JRE System Library，點(diǎn)擊 Remove
6. 點(diǎn)擊 Add Library → JRE System Library
7. 選擇 Workspace default JRE 或 Alternate JRE
8. 如果選擇 Alternate JRE，選擇所需的JDK版本
9. 點(diǎn)擊 Finish 和 Apply and Close

// settings.json
// ?? 重點(diǎn)提示：VS Code的Java擴(kuò)展配置，支持多JDK版本管理
{
    "java.configuration.runtimes": [
        {
            "name": "JavaSE-1.8",
            "path": "C:\\Java\\jdk-8",
            "default": false
        },
        {
            "name": "JavaSE-11",
            "path": "C:\\Java\\jdk-11",
            "default": false
        },
        {
            "name": "JavaSE-17",
            "path": "C:\\Java\\jdk-17",
            "default": true
        },
        {
            "name": "JavaSE-21",
            "path": "C:\\Java\\jdk-21",
            "default": false
        }
    ],
    "java.home": "C:\\Java\\jdk-17",
    "java.compile.nullAnalysis.mode": "automatic"
}

{
    "java.configuration.runtimes": [
        {
            "name": "JavaSE-11",
            "path": "C:\\Java\\jdk-11",
            "default": true
        }
    ],
    "java.home": "C:\\Java\\jdk-11"
}

echo %JAVA_HOME%
# 顯示空白或舊路徑

# 1. 檢查環(huán)境變量設(shè)置
echo %JAVA_HOME%

# 2. 重新打開命令提示符窗口
# 3. 或者刷新環(huán)境變量
set JAVA_HOME=C:\Java\jdk-17

# 4. 驗(yàn)證設(shè)置
echo %JAVA_HOME%
java -version

where java
# 顯示多個Java路徑或錯誤的路徑

# 1. 查看完整PATH
echo %PATH%

# 2. 清理PATH中的重復(fù)Java路徑
# 手動編輯系統(tǒng)環(huán)境變量，刪除重復(fù)或錯誤的路徑

# 3. 確保%JAVA_HOME%\bin在最前面
# PATH應(yīng)該類似：%JAVA_HOME%\bin;C:\Windows\System32;...

訪問被拒絕，無法修改系統(tǒng)環(huán)境變量

# 1. 以管理員身份運(yùn)行PowerShell
# 2. 設(shè)置系統(tǒng)環(huán)境變量
[Environment]::SetEnvironmentVariable("JAVA_HOME", "C:\Java\jdk-17", "Machine")

# 3. 或者設(shè)置用戶環(huán)境變量
[Environment]::SetEnvironmentVariable("JAVA_HOME", "C:\Java\jdk-17", "User")

java -version
# 顯示的版本與JAVA_HOME不匹配

# 1. 檢查JAVA_HOME設(shè)置
echo %JAVA_HOME%

# 2. 直接運(yùn)行JAVA_HOME中的java
%JAVA_HOME%\bin\java -version

# 3. 檢查PATH中java的位置
where java

# 4. 確保PATH中%JAVA_HOME%\bin在最前面

1. 重啟IDE
2. 清理IDE緩存
3. 重新配置JDK路徑
4. 檢查JDK安裝完整性

<!-- pom.xml中指定JDK版本 -->
<!-- ?? 實(shí)用技巧：在pom.xml中明確指定JDK版本，避免環(huán)境差異導(dǎo)致的構(gòu)建問題 -->
<properties>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
    <java.version>17</java.version>
</properties>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.11.0</version>
            <configuration>
                <source>17</source>
                <target>17</target>
            </configuration>
        </plugin>
    </plugins>
</build>

// build.gradle
java {
    sourceCompatibility = JavaVersion.VERSION_17
    targetCompatibility = JavaVersion.VERSION_17
}

// gradle.properties
org.gradle.java.home=C:\\Java\\jdk-17

C:\Java\
├── jdk-8\              # JDK 8 LTS
├── jdk-11\             # JDK 11 LTS  
├── jdk-17\             # JDK 17 LTS (主力)
├── jdk-21\             # JDK 21 LTS (新版)
├── current -> jdk-17\  # 當(dāng)前版本符號鏈接
└── tools\              # Java相關(guān)工具
    ├── maven\
    ├── gradle\
    └── scripts\        # 切換腳本

REM auto_switch.bat - 放在項(xiàng)目根目錄
REM ?? 重點(diǎn)提示：智能檢測項(xiàng)目類型，自動切換到項(xiàng)目所需的JDK版本
@echo off

REM 檢查項(xiàng)目類型和JDK要求
if exist "pom.xml" (
    REM Maven項(xiàng)目，檢查pom.xml中的Java版本
    findstr /C:"<java.version>" pom.xml > nul
    if not errorlevel 1 (
        for /f "tokens=2 delims=<>" %%a in ('findstr /C:"<java.version>" pom.xml') do (
            set PROJECT_JAVA_VERSION=%%a
        )
    )
) else if exist "build.gradle" (
    REM Gradle項(xiàng)目，檢查build.gradle中的Java版本
    findstr /C:"sourceCompatibility" build.gradle > nul
    if not errorlevel 1 (
        for /f "tokens=3" %%a in ('findstr /C:"sourceCompatibility" build.gradle') do (
            set PROJECT_JAVA_VERSION=%%a
        )
    )
)

REM 根據(jù)項(xiàng)目要求切換JDK
if defined PROJECT_JAVA_VERSION (
    echo Detected project Java version: %PROJECT_JAVA_VERSION%
    call switch_jdk.bat %PROJECT_JAVA_VERSION%
) else (
    echo No specific Java version detected, using default
)

REM 啟動開發(fā)環(huán)境
cmd /k

#!/bin/sh
# .git/hooks/post-checkout
# Git切換分支后自動切換JDK版本
# ?? 實(shí)用技巧：Git Hook自動化，每次切換分支自動設(shè)置對應(yīng)的JDK版本

if [ -f .jdkversion ]; then
    JDK_VERSION=$(cat .jdkversion)
    echo "Switching to JDK $JDK_VERSION for this project"
    
    # Windows環(huán)境調(diào)用批處理腳本
    if [ "$OS" = "Windows_NT" ]; then
        cmd //c "switch_jdk.bat $JDK_VERSION"
    fi
fi

# JDK Configuration for Project
[project]
name=MyProject
required_jdk=17
fallback_jdk=11

[paths]
windows=C:\Java\jdk-17
linux=/usr/lib/jvm/java-17-openjdk
macos=/usr/local/java/jdk-17

[maven]
java.version=17
maven.compiler.source=17
maven.compiler.target=17

# 項(xiàng)目名稱

## JDK要求

本項(xiàng)目需要 **JDK 17** 或更高版本。

### Windows環(huán)境JDK配置

1. 下載并安裝JDK 17：
   - Oracle JDK: https://www.oracle.com/java/technologies/downloads/
   - OpenJDK: https://adoptium.net/

2. 設(shè)置環(huán)境變量：
   ```cmd
   set JAVA_HOME=C:\Java\jdk-17
   set PATH=%JAVA_HOME%\bin;%PATH%

# 切換到JDK 17
switch_jdk.bat 17

# 驗(yàn)證版本
java -version

### 9.5 性能優(yōu)化建議

#### 9.5.1 JVM參數(shù)優(yōu)化

根據(jù)不同JDK版本優(yōu)化JVM參數(shù)：

```batch
REM JDK 8 優(yōu)化參數(shù)
set JAVA_OPTS=-Xms2g -Xmx4g -XX:+UseG1GC -XX:+UseStringDeduplication

REM JDK 11 優(yōu)化參數(shù)  
set JAVA_OPTS=-Xms2g -Xmx4g -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:+UseJVMCICompiler

REM JDK 17 優(yōu)化參數(shù)
set JAVA_OPTS=-Xms2g -Xmx4g -XX:+UseZGC -XX:+UnlockExperimentalVMOptions

<!-- Maven并行構(gòu)建 -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <fork>true</fork>
        <meminitial>128m</meminitial>
        <maxmem>512m</maxmem>
    </configuration>
</plugin>