java之Properties配置文件用法解读

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class demo01 {
    public static void main(String[] args) {
        Properties properties = new Properties();
        //使用ClassLoader加载properties配置文件生成对应的输入流
        InputStream in = demo01.class.getClassLoader().getResourceAsStream("config/config.properties");
        try {
            //使用properties对象加载输入流
            properties.load(in);
            //根据key获取对应的value
            String url = properties.getProperty("url");
            System.out.println("url:"+url);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Properties;

public class Demo02 {
    public static void main(String[] args) {
        Properties properties = new Properties();
        try {
            //使用InputStream流 读取配置文件
            BufferedReader bufferedReader = new BufferedReader(new FileReader("C:/Users/szwb093/Desktop/config.properties"));
            //使用properties对象加载输入流
            properties.load(bufferedReader);
            //根据key获取对应的value
            String url = properties.getProperty("url");
            System.out.println("url:"+url);

        } catch (FileNotFoundException e1) {
            e1.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}

//config为属性文件名，放在包config下，如果放在src下（资源文件夹下），直接用config即可
ResourceBundle resource = ResourceBundle.getBundle("config/config");
String url = resource.getString("url");
System.out.println("url:"+url);

/*
    Properties:用来读取配置文件
     */
    @Test
    public void test2() throws Exception {
        Properties pros = new Properties();
        //此时的文件默认在当前module下
        //读取配置文件的方式一
//        FileInputStream fis = new FileInputStream("jdbc1.properties");
   //     FileInputStream fis = new FileInputStream("src\\jdbc1.properties");

        pros.load(fis);

        //读取配置文件方式二
        //配置文件默认识别为：当前module的src下
        ClassLoader classloder = ClassLoaderTest.class.getClassLoader();
        InputStream is = classloder.getResourceAsStream("jdbc1.properties");
        pros.load(is);

        String user = pros.getProperty("user");
        String password = pros.getProperty("password");
        System.out.println("user =" + user + "password =" + password);
    }