JDK不会在默认路径下安装JVM。

除非您像ant一样需要外部工具来运行，否则非jdk就足以让Eclipse运行。安装这样的JVM最简单的方法是访问http://java.com，让它安装它想安装的任何东西。

然后再次双击Eclipse二进制文件。

我也遇到过这个问题。我的案例如下:

在文本:

HKEY_CURRENT_USER\Environment
    Path    REG_SZ    %JAVA_HOME%\bin;C:\ProgramFiles\nodejs

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment
    JAVA_HOME    REG_SZ    C:\ProgramFiles\Java\jdk
    Path    REG_EXPAND_SZ    C:\bin;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\
WindowsPowerShell\v1.0\;C:\Program Files\Intel\DMIX;c:\Program Files (x86)\Microsoft SQL Server\90\Tools\binn\;C:\Progra
m Files (x86)\Perforce;C:\ProgramFiles\010 Editor;C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;C:\ProgramFiles\
Git\cmd;C:\Program Files (x86)\Skype\Phone\

C:\Users\ssfang> echo %^JAVA_HOME% = "%^JAVA_HOME%" = %%JAVA_HOME%% %JAVA_HOME%
%JAVA_HOME% = "%^JAVA_HOME%" = %C:\ProgramFiles\Java\jdk% C:\ProgramFiles\Java\jdk

我发现他们的注册表值Path的类型是不同的，所以我用下面的命令检查路径是否有效:

C:\Users\ssfang> where node java
C:\ProgramFiles\nodejs\node.exe
INFO: Could not find "java".

因此，我通过以下命令(Setx)重置本地(当前用户)环境:

C:\Users\ssfang> setx PATH %^JAVA_HOME%\bin;"C:\ProgramFiles\nodejs"

SUCCESS: Specified value was saved.

C:\Users\ssfang> reg query HKEY_CURRENT_USER\Environment /v Path

HKEY_CURRENT_USER\Environment
    Path    REG_EXPAND_SZ    %JAVA_HOME%\bin;C:\ProgramFiles\nodejs

C:\Users\ssfang> where node java
C:\ProgramFiles\nodejs\node.exe
INFO: Could not find "java".

C:\Users\ssfang>echo %PATH%
C:\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Fi
les\Intel\DMIX;c:\Program Files (x86)\Microsoft SQL Server\90\Tools\binn\;C:\Program Files (x86)\Perforce;C:\ProgramFile
s\010 Editor;C:\Program Files\Microsoft SQL Server\130\Tools\Binn\;C:\ProgramFiles\Git\cmd;C:\Program Files (x86)\Skype\
Phone\;%JAVA_HOME%\bin;C:\ProgramFiles\nodejs

但是，在当前流程中，它不能将这些更改传播到其他正在运行的流程。

但是，如果直接在“注册表编辑器”中修改用户环境变量，

those modifications to the environment variables do not result in immediate change. For example, if you start another Command Prompt after making the changes, the environment variables will reflect the previous (not the current) values. The changes do not take effect until you log off and then log back on. To effect these changes without having to log off, broadcast a WM_SETTINGCHANGE message to all windows in the system, so that any interested applications (such as Windows Explorer, Program Manager, Task Manager, Control Panel, and so forth) can perform an update.

详细信息请参见如何将环境变量传播到系统

在这里，我给出了一个powershell脚本来完成它:

# powershell -ExecutionPolicy ByPass -File
# Standard, inline approach: (i.e. behaviour you'd get when using & in Linux)
# START /B CMD /C CALL "foo.bat" [args [...]]
# powershell -ExecutionPolicy ByPass -WindowStyle Hidden -File myScript.ps1 


<#
Add-Type @'

public class CSharp
{
    public static void Method(object[] first, object[] second)
    {
        System.Console.WriteLine("Hello world");
    }
}
'@
$a = 1..4;
[string[]]$b = "a","b","c","d";
[CSharp]::Method($a, $b);
#>


<#

#http://stackoverflow.com/questions/16552801/how-do-i-conditionally-add-a-class-with-add-type-typedefinition-if-it-isnt-add

#Problem Add-Type : Cannot add type. The type name 'PInvoke.User32' already exists.

if (-not ("MyClass" -as [type])) {
    add-type @"
    public class MyClass { }
"@
}


p.s. there's no Remove-Type; see this answer for more on how to best work around this limitation:
http://stackoverflow.com/questions/3369662/can-you-remove-an-add-ed-type-in-powershell-again

I think it will be wanted when debugging.
It is much simpler to close a tab in Console and open new one in PowerShell_ISE.exe or close PowerShell.exe.

Or

Start-Job -ScriptBlock {
    param([uri]$url,$OutputDir)
    # download and save pages
    Invoke-RestMethod $url | Out-File "$OutputDir\$($url.Segments[-1])" -Force
} -ArgumentList $link,$OutputDir

#>
if (-not ([System.Management.Automation.PSTypeName]'PInvoke.Program').Type)
{
    $sig=@"
using System;
using System.Runtime.InteropServices;
using System.Text;
using System.Collections.Generic;

// The global namespace is the "root" namespace: global::system will always refer to the .NET Framework namespace System.

///P/Invoke (Platform Invoke)
namespace PInvoke
{
    public static class User32
    {
        /// http://www.pinvoke.net/default.aspx/Constants/HWND.html
        // public const IntPtr HWND_BROADCAST = new IntPtr(0xffff);
        /// https://msdn.microsoft.com/en-us/library/windows/desktop/ms725497(v=vs.85).aspx
        /// http://www.pinvoke.net/default.aspx/Constants/WM.html
        public const UInt32 WM_SETTINGCHANGE = 0x001A;

        // SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0,    (LPARAM) "Environment", SMTO_ABORTIFHUNG,    5000, &dwReturnValue);

        /// https://msdn.microsoft.com/en-us/library/windows/desktop/ms644952(v=vs.85).aspx
        /// If the function succeeds, the return value is nonzero. 
        [System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "SendMessageTimeout", SetLastError = true)]
        public static extern uint SendMessageTimeout(IntPtr hWnd, uint Msg, int wParam, string lParam, SendMessageTimeoutFlags fuFlags, uint uTimeout, out int lpdwResult);
    }

    [Flags]
    public enum SendMessageTimeoutFlags : uint
    {
        SMTO_NORMAL = 0x0,
        SMTO_BLOCK = 0x1,
        SMTO_ABORTIFHUNG = 0x2,
        SMTO_NOTIMEOUTIFNOTHUNG = 0x8,
        SMTO_ERRORONEXIT = 0x20
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            //int innerPinvokeResult;
            //uint pinvokeResult = User32.SendMessageTimeout(User32.HWND_BROADCAST, User32.WM_SETTINGCHANGE, 0, "Environment", SendMessageTimeoutFlags.SMTO_NORMAL, 1000, out innerPinvokeResult);
            Console.WriteLine("Over!!!!!!!!!!!!!!!!!!!!!!!!!");
        }
    }
}
"@

    Add-Type -TypeDefinition $sig
}


## [PInvoke.Program]::Main([IntPtr]::Zero);

$innerPinvokeResult=[int]0
[PInvoke.User32]::SendMessageTimeout([IntPtr]0xffff, [PInvoke.User32]::WM_SETTINGCHANGE, 0, "Environment", [PInvoke.SendMessageTimeoutFlags]::SMTO_NORMAL, 1000, [ref]$innerPinvokeResult);

对于Setx Setx [/s [/u [] [/p]]]]] [/m]

/m Specifies to set the variable in the system environment. The default setting is the local environment

我用的是64位的windows 7，我用eclipse时也遇到了同样的问题。为了让它工作，我必须使用internet explorer(64位版本)来下载java。这是让java安装64位版本的唯一方法。当我用firefox安装java时，它自动安装了32位版本(太蠢了!)Eclipse 64位版本不会检测java 32位版本。

设置JAVA_HOME变量和ad JAVA_HOME/bin为环境路径变量。

只需在环境变量中添加JRE PATH FOR Ex: C:\Program Files\Java\jre5\bin 把“;”放在每条路径之间。然后点击eclipse.exe，它将工作.....

在eclipse文件夹中创建一个批处理文件，并在其中写入:

eclipse -vm C:\Sun\SDK\jdk\jre\bin\javaw.exe

看到 http://wiki.eclipse.org/FAQ_How_do_I_run_Eclipse%3F