java - Properties

package properties;

import java.io.FileReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Properties;

public class PropertiesTest {
    public static void main(String[] args){
        Properties p = new Properties();
        try {
            System.out.println("--------------------读取key对应的value----------------------");
            p.load(new FileReader("src//properties//Test.properties"));
            String s = p.getProperty("key1"); //默认是String，会返回key = 后面的东西，不用加""等
            System.out.println(s);
            //aaa


            System.out.println("--------------------返回所有key遍历----------------------");
            @SuppressWarnings("unchecked")
            Enumeration e = p.propertyNames();
            while(e.hasMoreElements()){
                String key = (String)e.nextElement();
                System.out.println(key + " = " + p.getProperty(key));
            }
            //key3 = ccc
            //key2 = bbb
            //key1 = aaa
            //因为是map所以无序，返回顺序与存储顺序不一致


        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

key1 = aaa
key2 = bbb
key3 = ccc