java properties增删改查详解编程语言

java properties增删改查 
 
 public static void main(String args[]) throws IOException { 
  Properties prop = new Properties(); 
  OutputStream out = new FileOutputStream("D://workspace//JavaStudy//src//test//test.properties"); 
   
  /** 
   * 新增逻辑： 
   * 1.必须先读取文件原有内容 
   * 2.增加新的记录以后，再一起保存 
   */ 
  //1.先读取文件原有内容 
  Map toSaveMap = new HashMap(); 
  Set keys = prop.keySet(); 
  for(Iterator itr = keys.iterator(); itr.hasNext();){ 
   String key = (String) itr.next(); 
   Object value = prop.get(key); 
   toSaveMap.put(key, value); 
  } 
  //2.增加你需要增加的属性内容 
  toSaveMap.put("name", "zhang san"); 
  toSaveMap.put("age", "25"); 
  prop.putAll(toSaveMap); 
  prop.store(out, "==== after add ===="); 
   
  /** 
   * 修改逻辑：重新设置对应Key的值即可，非常简单 
   */ 
  prop.clear(); 
  toSaveMap.put("name", "li si"); 
  toSaveMap.put("age", "26"); 
  prop.putAll(toSaveMap); 
  prop.store(out, "==== after modify ===="); 
   
  /** 
   * 删除逻辑：找到对应的key，删除即可 
   */   
  prop.clear(); 
  toSaveMap.remove("name"); 
  prop.putAll(toSaveMap); 
  prop.store(out, "==== after remove ====")); 
   
  /** 
   * 查询逻辑： 
   */ 
  InputStream in = new FileInputStream("D://workspace//JavaStudy//src//test//test.properties"); 
  prop.load(in); 
  System.out.println("name: " + prop.get("name")); 
  System.out.println("age: " + prop.get("age")); 
   
 }