java 读取系统Properties代码实例

import java.util.*;
 
public class PropertiesTest {
 
  public static void main(String[] args) {
 
    Properties properties = System.getProperties();
    PropertiesTest pt = new PropertiesTest();
    Map<String,String> map = pt.getSpecialMap(properties);
    //便于方便读取，配置较多的属性打印出来
    pt.showMap(map);
  }
 
 
  Map<String,String> getSpecialMap(Properties properties){
 
    Set<Map.Entry<Object,Object>> props = properties.entrySet();
    Map<String,String> map = new HashMap<String, String>();
    Iterator<Map.Entry<Object, Object>> it = props.iterator();
    while (it.hasNext()) {
      Map.Entry<Object,Object> entry = it.next();
      System.out.println("key= " + entry.getKey() );
      System.out.println("value= " + entry.getValue());
      if("java.library.path".equalsIgnoreCase("" + entry.getKey())) {
        map.put(entry.getKey()+"",entry.getValue()+"");
      }
      if("java.class.path".equalsIgnoreCase("" + entry.getKey())) {
        map.put(entry.getKey()+"",entry.getValue()+"");
      }
      if ("sun.boot.class.path".equalsIgnoreCase("" + entry.getKey())) {
        map.put(entry.getKey()+"",entry.getValue()+"");
      }
      if("java.ext.dirs".equalsIgnoreCase("" + entry.getKey())) {
        map.put(entry.getKey()+"",entry.getValue()+"");
      }
    }
    return map;
  }
 
 
  void showMap(Map<String,String> map) {
    for (Map.Entry<String, String> entry : map.entrySet()) {
      System.out.println("----------------------------------------------------");
      System.out.println(entry.getKey() +":");
      splitStr(entry.getValue());
      System.out.println("----------------------------------------------------");
    }
  }
 
  void splitStr(String string) {
    String[] str = string.split(";");
    for (int i = 0; i < str.length; i++) {
      System.out.println(str[i]);
    }
  }
}