String osName = System.getProperty("os.name");
System.out.println("Operating system " + osName);

我喜欢沃尔夫冈的回答，只是因为我相信这样的事情应该是consts……

所以我把它重新措辞了一下，并想分享一下:)

/**
 * types of Operating Systems
 *
 * please keep the note below as a pseudo-license
 *
 * helper class to check the operating system this Java VM runs in
 * 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
 */
public enum OSType {
    MacOS("mac", "darwin"),
    Windows("win"),
    Linux("nux"),
    Other("generic");

    private static OSType detectedOS;

    private final String[] keys;

    private OSType(String... keys) {
        this.keys = keys;
    }

    private boolean match(String osKey) {
        for (int i = 0; i < keys.length; i++) {
            if (osKey.indexOf(keys[i]) != -1)
                return true;
        }
        return false;
    }

    public static OSType getOS_Type() {
        if (detectedOS == null)
            detectedOS = getOperatingSystemType(System.getProperty("os.name", Other.keys[0]).toLowerCase());
        return detectedOS;
    }

    private static OSType getOperatingSystemType(String osKey) {
        for (OSType osType : values()) {
            if (osType.match(osKey))
                return osType;
        }
        return Other;
    }
}

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;
  }
}

String osName = System.getProperty("os.name");
System.out.println("Operating system " + osName);

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?”

你可以使用:

System.getProperty("os.name")

附注:你可能会发现这段代码很有用:

class ShowProperties {
    public static void main(String[] args) {
        System.getProperties().list(System.out);
    }
}

它所做的就是打印出Java实现提供的所有属性。它将使您了解通过属性可以了解Java环境的哪些信息。: -)