Java的System.getProperty详解

package javax.org.lang;
/**
 * @Date: 2013-6-18
 * @Author: jilongliang
 * @Description：System.getProperty详解
 */
@SuppressWarnings("all")
public class SysProperty {
	public static void main(String[] args) {
		System.out.println(compiler());
	}
	/**获取操作系统名称*/
	private static String osName() {
		return System.getProperty("os.name");
	}
	/**获取操作系统版本*/
	private static String osVersion() {
		return System.getProperty("os.version");
	}
	/**获取Java运行时环境供应商*/
	private static String vendor() {
		return System.getProperty("java.vendor");
	}
	/**获取Java供应商的 URL*/
	private static String vendorUrl() {
		return System.getProperty("java.vendor.url");
	}
	/**Java 安装目录*/
	private static String home() {
		return System.getProperty("java.home");
	}
	/**获取类的版本*/
	private static String classVersion() {
		return System.getProperty("java.class.version");
	}
	/**
	 * Java 类路径
	 * @return
	 */
	private static String classPath() {
		return System.getProperty("java.class.path");
	}
	/**
	 * 操作系统的架构
	 * @return
	 */
	private static String osArch() {

		return System.getProperty("os.arch");
	}
	/**
	 * 获取用户的账户名称
	 * @return
	 */
	private static String userName() {
		return System.getProperty("user.name");
	}
	/**
	 * 获取用户的主目录
	 * @return
	 */
	private static String userHome() {
		return System.getProperty("user.home");
	}
	/**
	 * 用户的当前工作目录
	 * @return
	 */
	private static String userDir() {
		return System.getProperty("user.dir");
	}
	/**
	 * Java 虚拟机规范版本
	 * @return
	 */
	private static String vmSpecificationVersion() {
		return System.getProperty("java.vm.specification.version");
	}
	/**
	 * Java 虚拟机规范供应商
	 * @return
	 */
	private static String vmSpecificationVendor() {
		return System.getProperty("java.vm.specification.vendor");
	}
	/**
	 * Java 虚拟机规范名称
	 * @return
	 */
	private static String vmSpecificationName() {
		return System.getProperty("java.vm.specification.name");
	}
	/**
	 * Java 虚拟机实现版本
	 * @return
	 */
	private static String vmVersion() {
		return System.getProperty("java.vm.version");
	}
	/**
	 * Java 虚拟机实现供应商
	 * @return
	 */
	private static String vmVendor() {
		return System.getProperty("java.vm.vendor");
	}
	/**
	 * Java 虚拟机实现名称
	 * @return
	 */
	private static String vmName() {
		return System.getProperty("java.vm.name");
	}
	/**
	 * 一个或多个扩展目录的路径
	 * @return
	 */
	private static String extDirs() {
		return System.getProperty("java.ext.dirs");
	}	
	/**
	 *加载库时搜索的路径列表
	 * @return
	 */
	private static String library() {
		return System.getProperty("java.library.path");
	}
	/**
	 * 文件分隔符（在 UNIX 系统中是“/”）
	 * @return
	 */
	private static String fileSeparator() {
		return System.getProperty("file.separator");
	}
	/**
	 * 路径分隔符（在 UNIX 系统中是“:”）
	 * @return
	 */
	private static String pathSeparator() {
		return System.getProperty("path.separator");
	}
	/**
	 * 行分隔符（在 UNIX 系统中是“/n”）
	 * @return
	 */
	private static String lineSeparator() {
		return System.getProperty("line.separator");
	}
	/**
	 * 要使用的 JIT 编译器的名称
	 * @return
	 */
	private static String compiler() {
		return System.getProperty("java.compiler");
	}

	/**
	 * C:\Users\ADMINI~1\AppData\Local\Temp\ 获取当前临时目录
	 * 
	 * @return
	 */
	public static String getSystempPath() {
		return System.getProperty("java.io.tmpdir");
	}

	/**
	 * 以\分割
	 * 
	 * @return
	 */
	public static String getSeparator() {
		return System.getProperty("file.separator");
	}

	/**
	 * 如:file:/D:/Workspaces/MyEclipse%208.6/myapp/WebRoot/WEB-INF/classes/未处理
	 * 处理后：D:\Workspaces\MyEclipse%208.6\napp\WebRoot\ 获取当前项目的路径
	 * 
	 * @return
	 */
	public static String getSysPath() {
		String path = Thread.currentThread().getContextClassLoader()
				.getResource("").toString();
		System.out.println(path);
		String temp = path.replaceFirst("file:/", "").replaceFirst("WEB-INF/classes/", "");
		String separator = System.getProperty("file.separator");
		String resultPath = temp.replaceAll("/", separator + separator);
		return resultPath;
	}

	/**
	 * 未处理 D:/Workspaces/MyEclipse%208.6/myapp/WebRoot/WEB-INF/classes/ 已处理
	 * D:\Workspaces\MyEclipse%208.6\myapp\WebRoot\WEB-INF\classes\
	 * 
	 * @return
	 */
	public static String getClassPath() {
		String path = Thread.currentThread().getContextClassLoader().getResource("").toString();
		String temp = path.replaceFirst("file:/", "");
		String separator = System.getProperty("file.separator");
		String resultPath = temp.replaceAll("/", separator + separator);
		return resultPath;
	}

}

package com.org;

import java.io.File;

public class SystemUtils
{
  private static final String OS_NAME_WINDOWS_PREFIX = "Windows";
  private static final String USER_HOME_KEY = "user.home";
  private static final String USER_DIR_KEY = "user.dir";
  private static final String JAVA_IO_TMPDIR_KEY = "java.io.tmpdir";
  private static final String JAVA_HOME_KEY = "java.home";
  public static final String AWT_TOOLKIT = getSystemProperty("awt.toolkit");

  public static final String FILE_ENCODING = getSystemProperty("file.encoding");

  public static final String FILE_SEPARATOR = getSystemProperty("file.separator");

  public static final String JAVA_AWT_FONTS = getSystemProperty("java.awt.fonts");

  public static final String JAVA_AWT_GRAPHICSENV = getSystemProperty("java.awt.graphicsenv");

  public static final String JAVA_AWT_HEADLESS = getSystemProperty("java.awt.headless");

  public static final String JAVA_AWT_PRINTERJOB = getSystemProperty("java.awt.printerjob");

  public static final String JAVA_CLASS_PATH = getSystemProperty("java.class.path");

  public static final String JAVA_CLASS_VERSION = getSystemProperty("java.class.version");

  public static final String JAVA_COMPILER = getSystemProperty("java.compiler");

  public static final String JAVA_ENDORSED_DIRS = getSystemProperty("java.endorsed.dirs");

  public static final String JAVA_EXT_DIRS = getSystemProperty("java.ext.dirs");

  public static final String JAVA_HOME = getSystemProperty("java.home");

  public static final String JAVA_IO_TMPDIR = getSystemProperty("java.io.tmpdir");

  public static final String JAVA_LIBRARY_PATH = getSystemProperty("java.library.path");

  public static final String JAVA_RUNTIME_NAME = getSystemProperty("java.runtime.name");

  public static final String JAVA_RUNTIME_VERSION = getSystemProperty("java.runtime.version");

  public static final String JAVA_SPECIFICATION_NAME = getSystemProperty("java.specification.name");

  public static final String JAVA_SPECIFICATION_VENDOR = getSystemProperty("java.specification.vendor");

  public static final String JAVA_SPECIFICATION_VERSION = getSystemProperty("java.specification.version");

  public static final String JAVA_UTIL_PREFS_PREFERENCES_FACTORY = getSystemProperty("java.util.prefs.PreferencesFactory");

  public static final String JAVA_VENDOR = getSystemProperty("java.vendor");

  public static final String JAVA_VENDOR_URL = getSystemProperty("java.vendor.url");

  public static final String JAVA_VERSION = getSystemProperty("java.version");

  public static final String JAVA_VM_INFO = getSystemProperty("java.vm.info");

  public static final String JAVA_VM_NAME = getSystemProperty("java.vm.name");

  public static final String JAVA_VM_SPECIFICATION_NAME = getSystemProperty("java.vm.specification.name");

  public static final String JAVA_VM_SPECIFICATION_VENDOR = getSystemProperty("java.vm.specification.vendor");

  public static final String JAVA_VM_SPECIFICATION_VERSION = getSystemProperty("java.vm.specification.version");

  public static final String JAVA_VM_VENDOR = getSystemProperty("java.vm.vendor");

  public static final String JAVA_VM_VERSION = getSystemProperty("java.vm.version");

  public static final String LINE_SEPARATOR = getSystemProperty("line.separator");

  public static final String OS_ARCH = getSystemProperty("os.arch");

  public static final String OS_NAME = getSystemProperty("os.name");

  public static final String OS_VERSION = getSystemProperty("os.version");

  public static final String PATH_SEPARATOR = getSystemProperty("path.separator");

  public static final String USER_COUNTRY = getSystemProperty("user.country") == null ? getSystemProperty("user.region") : getSystemProperty("user.country");

  public static final String USER_DIR = getSystemProperty("user.dir");

  public static final String USER_HOME = getSystemProperty("user.home");

  public static final String USER_LANGUAGE = getSystemProperty("user.language");

  public static final String USER_NAME = getSystemProperty("user.name");

  public static final String USER_TIMEZONE = getSystemProperty("user.timezone");

  public static final String JAVA_VERSION_TRIMMED = getJavaVersionTrimmed();

  public static final float JAVA_VERSION_FLOAT = getJavaVersionAsFloat();

  public static final int JAVA_VERSION_INT = getJavaVersionAsInt();

  public static final boolean IS_JAVA_1_1 = getJavaVersionMatches("1.1");

  public static final boolean IS_JAVA_1_2 = getJavaVersionMatches("1.2");

  public static final boolean IS_JAVA_1_3 = getJavaVersionMatches("1.3");

  public static final boolean IS_JAVA_1_4 = getJavaVersionMatches("1.4");

  public static final boolean IS_JAVA_1_5 = getJavaVersionMatches("1.5");

  public static final boolean IS_JAVA_1_6 = getJavaVersionMatches("1.6");

  public static final boolean IS_OS_AIX = getOSMatches("AIX");

  public static final boolean IS_OS_HP_UX = getOSMatches("HP-UX");

  public static final boolean IS_OS_IRIX = getOSMatches("Irix");

  public static final boolean IS_OS_LINUX = (getOSMatches("Linux")) || (getOSMatches("LINUX"));

  public static final boolean IS_OS_MAC = getOSMatches("Mac");

  public static final boolean IS_OS_MAC_OSX = getOSMatches("Mac OS X");

  public static final boolean IS_OS_OS2 = getOSMatches("OS/2");

  public static final boolean IS_OS_SOLARIS = getOSMatches("Solaris");

  public static final boolean IS_OS_SUN_OS = getOSMatches("SunOS");

  public static final boolean IS_OS_UNIX = (IS_OS_AIX) || (IS_OS_HP_UX) || (IS_OS_IRIX) || (IS_OS_LINUX) || (IS_OS_MAC_OSX) || (IS_OS_SOLARIS) || (IS_OS_SUN_OS);

  public static final boolean IS_OS_WINDOWS = getOSMatches("Windows");

  public static final boolean IS_OS_WINDOWS_2000 = getOSMatches("Windows", "5.0");

  public static final boolean IS_OS_WINDOWS_95 = getOSMatches("Windows 9", "4.0");

  public static final boolean IS_OS_WINDOWS_98 = getOSMatches("Windows 9", "4.1");

  public static final boolean IS_OS_WINDOWS_ME = getOSMatches("Windows", "4.9");

  public static final boolean IS_OS_WINDOWS_NT = getOSMatches("Windows NT");

  public static final boolean IS_OS_WINDOWS_XP = getOSMatches("Windows", "5.1");

  /** @deprecated */
  public static float getJavaVersion()
  {
    return JAVA_VERSION_FLOAT;
  }

  private static float getJavaVersionAsFloat()
  {
    if (JAVA_VERSION_TRIMMED == null) {
      return 0.0F;
    }
    String str = JAVA_VERSION_TRIMMED.substring(0, 3);
    if (JAVA_VERSION_TRIMMED.length() >= 5)
      str = str + JAVA_VERSION_TRIMMED.substring(4, 5);
    try
    {
      return Float.parseFloat(str); } catch (Exception ex) {
    }
    return 0.0F;
  }

  private static int getJavaVersionAsInt()
  {
    if (JAVA_VERSION_TRIMMED == null) {
      return 0;
    }
    String str = JAVA_VERSION_TRIMMED.substring(0, 1);
    str = str + JAVA_VERSION_TRIMMED.substring(2, 3);
    if (JAVA_VERSION_TRIMMED.length() >= 5)
      str = str + JAVA_VERSION_TRIMMED.substring(4, 5);
    else
      str = str + "0";
    try
    {
      return Integer.parseInt(str); } catch (Exception ex) {
    }
    return 0;
  }

  private static String getJavaVersionTrimmed()
  {
    if (JAVA_VERSION != null) {
      for (int i = 0; i < JAVA_VERSION.length(); i++) {
        char ch = JAVA_VERSION.charAt(i);
        if ((ch >= '0') && (ch <= '9')) {
          return JAVA_VERSION.substring(i);
        }
      }
    }
    return null;
  }

  private static boolean getJavaVersionMatches(String versionPrefix)
  {
    if (JAVA_VERSION_TRIMMED == null) {
      return false;
    }
    return JAVA_VERSION_TRIMMED.startsWith(versionPrefix);
  }

  private static boolean getOSMatches(String osNamePrefix)
  {
    if (OS_NAME == null) {
      return false;
    }
    return OS_NAME.startsWith(osNamePrefix);
  }

  private static boolean getOSMatches(String osNamePrefix, String osVersionPrefix)
  {
    if ((OS_NAME == null) || (OS_VERSION == null)) {
      return false;
    }
    return (OS_NAME.startsWith(osNamePrefix)) && (OS_VERSION.startsWith(osVersionPrefix));
  }

  private static String getSystemProperty(String property)
  {
    try
    {
      return System.getProperty(property);
    }
    catch (SecurityException ex) {
      System.err.println("Caught a SecurityException reading the system property '" + property + "'; the SystemUtils property value will default to null.");
    }

    return null;
  }

  public static boolean isJavaVersionAtLeast(float requiredVersion)
  {
    return JAVA_VERSION_FLOAT >= requiredVersion;
  }

  public static boolean isJavaVersionAtLeast(int requiredVersion)
  {
    return JAVA_VERSION_INT >= requiredVersion;
  }

  public static boolean isJavaAwtHeadless()
  {
    return JAVA_AWT_HEADLESS != null ? JAVA_AWT_HEADLESS.equals(Boolean.TRUE.toString()) : false;
  }

  public static File getJavaHome()
  {
    return new File(System.getProperty("java.home"));
  }

  public static File getJavaIoTmpDir()
  {
    return new File(System.getProperty("java.io.tmpdir"));
  }

  public static File getUserDir()
  {
    return new File(System.getProperty("user.dir"));
  }

  public static File getUserHome()
  {
    return new File(System.getProperty("user.home"));
  }
}