Properties class inherits HashTable class, generally used to configure the properties file.

package com.itcast.demo04.Prop;

import jdk.internal.util.xml.impl.ReaderUTF8;
import sun.nio.cs.UTF_32;
import sun.nio.cs.ext.GBK;

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

/**
 * @author newcityman
 * @date 2019/7/28 - 12:50
 */
public class Demo01Properties {
 public static void main(String[] args) throws IOException {
// show01();
// show02();
 show03();

 }

 private static void show03() throws IOException {
 Properties prop = new Properties();
 prop.load(new FileReader("day18_IOAndProperties\\prop.txt"));
 Set<String> key = prop.stringPropertyNames();
 for (String s : key) {
 String value = prop.getProperty(s);
 System.out.println(s+"==>"+value);
 }
 }

 private static void show02() throws IOException {
 Properties prop = new Properties();
 prop.setProperty("张曼玉","16");
 prop.setProperty("张学友","20");
 prop.setProperty("刘德华","18");

 FileWriter fw = new FileWriter("day18_IOAndProperties\\prop.txt");

 prop.store(fw, "data");
 }


 private static void show01() {
 Properties prop = new Properties();
 prop.setProperty("zmy","12");
 prop.setProperty("zyy","20");
 prop.setProperty("lm","15");
 prop.setProperty("zgh","16");
 Set<String> strings = prop.stringPropertyNames();
 for (String key : strings) {
 String value = prop.getProperty(key);
 System.out.println(key+"====>"+value);
 }

 }
}