下面的代码显示了你可以从System API得到的值，这些都可以通过这个API得到。

public class App {
    public static void main( String[] args ) {
        //Operating system name
        System.out.println(System.getProperty("os.name"));

        //Operating system version
        System.out.println(System.getProperty("os.version"));

        //Path separator character used in java.class.path
        System.out.println(System.getProperty("path.separator"));

        //User working directory
        System.out.println(System.getProperty("user.dir"));

        //User home directory
        System.out.println(System.getProperty("user.home"));

        //User account name
        System.out.println(System.getProperty("user.name"));

        //Operating system architecture
        System.out.println(System.getProperty("os.arch"));

        //Sequence used by operating system to separate lines in text files
        System.out.println(System.getProperty("line.separator"));

        System.out.println(System.getProperty("java.version")); //JRE version number

        System.out.println(System.getProperty("java.vendor.url")); //JRE vendor URL

        System.out.println(System.getProperty("java.vendor")); //JRE vendor name

        System.out.println(System.getProperty("java.home")); //Installation directory for Java Runtime Environment (JRE)

        System.out.println(System.getProperty("java.class.path"));

        System.out.println(System.getProperty("file.separator"));
    }
}

答案:-

Windows 7
6.1
;
C:\Users\user\Documents\workspace-eclipse\JavaExample
C:\Users\user
user
amd64


1.7.0_71
http://java.oracle.com/
Oracle Corporation
C:\Program Files\Java\jre7
C:\Users\user\Documents\workspace-Eclipse\JavaExample\target\classes
\

以下JavaFX类有静态方法来确定当前的操作系统(isWindows()，isLinux()…):

com.sun.javafx.PlatformUtil com.sun.media.jfxmediaimpl.HostUtils com.sun.javafx.util.Utils

例子:

if (PlatformUtil.isWindows()){
           ...
}

你想要实现的一个小例子可能是一个类似于下面的类:

import java.util.Locale;

public class OperatingSystem
{
    private static String OS = System.getProperty("os.name", "unknown").toLowerCase(Locale.ROOT);

    public static boolean isWindows()
    {
        return OS.contains("win");
    }

    public static boolean isMac()
    {
        return OS.contains("mac");
    }

    public static boolean isUnix()
    {
        return OS.contains("nux");
    }
}

这个特殊的实现非常可靠，应该是普遍适用的。只需复制粘贴到你选择的类。

上面答案中的一些链接似乎被打破了。我在下面的代码中添加了指向当前源代码的指针，并提供了一种方法来处理以enum作为答案的检查，以便在计算结果时使用switch语句:

OsCheck.OSType ostype=OsCheck.getOperatingSystemType();
switch (ostype) {
    case Windows: break;
    case MacOS: break;
    case Linux: break;
    case Other: break;
}

helper类是:

/**
 * helper class to check the operating system this Java VM runs in
 *
 * please keep the notes below as a pseudo-license
 *
 * http://stackoverflow.com/questions/228477/how-do-i-programmatically-determine-operating-system-in-java
 * compare to http://svn.terracotta.org/svn/tc/dso/tags/2.6.4/code/base/common/src/com/tc/util/runtime/Os.java
 * http://www.docjar.com/html/api/org/apache/commons/lang/SystemUtils.java.html
 */
import java.util.Locale;
public static final class OsCheck {
  /**
   * types of Operating Systems
   */
  public enum OSType {
    Windows, MacOS, Linux, Other
  };

  // cached result of OS detection
  protected static OSType detectedOS;

  /**
   * detect the operating system from the os.name System property and cache
   * the result
   * 
   * @returns - the operating system detected
   */
  public static OSType getOperatingSystemType() {
    if (detectedOS == null) {
      String OS = System.getProperty("os.name", "generic").toLowerCase(Locale.ENGLISH);
      if ((OS.indexOf("mac") >= 0) || (OS.indexOf("darwin") >= 0)) {
        detectedOS = OSType.MacOS;
      } else if (OS.indexOf("win") >= 0) {
        detectedOS = OSType.Windows;
      } else if (OS.indexOf("nux") >= 0) {
        detectedOS = OSType.Linux;
      } else {
        detectedOS = OSType.Other;
      }
    }
    return detectedOS;
  }
}

2008年10月:

我建议将它缓存到一个静态变量中:

public static final class OsUtils
{
   private static String OS = null;
   public static String getOsName()
   {
      if(OS == null) { OS = System.getProperty("os.name"); }
      return OS;
   }
   public static boolean isWindows()
   {
      return getOsName().startsWith("Windows");
   }

   public static boolean isUnix() // and so on
}

这样，每次请求o时，在应用程序的生命周期内只获取一次属性。

2016年2月:7年多后:

Windows 10有一个错误(在最初的答案时不存在)。 参见“Java的“os.name”for Windows 10?”

我发现Swingx的操作系统Utils可以完成这项工作。