Properties属性文件

package com.jdk7.chapter4;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

public class PropertiesTest {
    public static void main(String[] args) throws IOException {
        Properties prop1 = new Properties();
        prop1.setProperty("001", "ssss");
        prop1.setProperty("004", "tttt");
        prop1.setProperty("003", "jjjj");
        prop1.setProperty("002", "pppp");
        prop1.setProperty("002", "rrrr");    //Properties不允许key重复，如果重复则采用最后一组
        System.out.println("001: "+prop1.getProperty("001"));
        System.out.println("004: "+prop1.getProperty("004"));
        System.out.println("003: "+prop1.getProperty("003"));
        System.out.println("002: "+prop1.getProperty("002"));
        System.out.println("other: "+prop1.getProperty("other1", "none"));  //不存在的key返回默认值
        
        String fileName1 = "D:/software/eclipse/workspace/JDK7/src/com/jdk7/chapter4/testout.properties";
        String fileName2 = "D:/software/eclipse/workspace/JDK7/src/com/jdk7/chapter4/testin.properties";
        FileOutputStream out = new FileOutputStream(fileName1);
        prop1.store(out, "test");
        out.close();
        
        FileInputStream in = new FileInputStream(fileName2);
        prop1.load(in);
        in.close();
        System.out.println("username: "+prop1.getProperty("username"));
        System.out.println("password: "+prop1.getProperty("password"));
        
        prop1.list(System.out);        //将Properties中的数据输出到一个输出流中
    }
}

执行结果：
001: ssss
004: tttt
003: jjjj
002: rrrr
other: none
username: admin
password: 123
-- listing properties --
password=123
004=tttt
003=jjjj
002=rrrr
001=ssss
username=admin