Properties

//Properties是一个持久的类 可以存在流中 或者从流中加载数据
//Properties是Hashtable的子类   实现了Map接口，Map集合 

package cn.lijun.demo3;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Properties;
import java.util.Set;

public class PropertiesDemo {
    public static void main(String[] args) throws Exception {
        //fun();
        //fun2();
        fun3();
    }
    //存 store(OutputStream out)  store(Write w)
    public static void fun3() throws IOException{
        Properties p=new Properties();
        p.setProperty("name", "李登");
        p.setProperty("age", "22");
        p.setProperty("id", "001");
        p.setProperty("email", "20101634510@qq.com");
        p.setProperty("six", "女");
        FileWriter f=new FileWriter("d:\wang.properties");
        p.store(f, "");
        f.close();
    }
    //Properties集合 特有方法  load(InputStream in) load(Reader r)
    //流对象读取键值对
    public static void fun2() throws Exception{
        Properties v=new Properties();
        FileReader fr=new FileReader("d:\wang.properties");
        v.load(fr);
        fr.close();
        System.out.println(v);
    }

    //关于Properties集 添加数据 获取数据 遍历数据
    public static void fun(){
        Properties v=new Properties();
        v.setProperty("a", "1");
        v.setProperty("b", "2");
        v.setProperty("c", "3");
        v.setProperty("d", "4");
        String s=v.getProperty("a");
        System.out.println(s);
        Set<String> se = v.stringPropertyNames();
        for(String k: se){
            System.out.println(k+"  "+v.getProperty(k));
        }
      }

}