IOC读取配置文件

1. 创建一个bean文件

package com.longteng.utils;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Component
public class DbUtils {
    @Value ("${db.test1.ip}")
    private String ip;
    @Value ("${db.test1.port}")
    private int port;
    @Value ("${db.test1.userName}")
    private String userName;
    @Value ("${db.test1.pwd}")
    private String password;
    @PostConstruct
    public  void initDb(){
        System.out.println ("初始化数据库。。。。。。");
        System.out.println (""+toString ());
    }

    @Override
    public String toString() {
        return "DbUtils{" +
                "ip='" + ip + '\'' +
                ", port=" + port +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                '}';
    }

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        this.ip = ip;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

2、创建db.properties配置文件

db.test1.ip=127.0.0.1
db.test1.port=
db.test1.userName=zhou
db.test1.pwd=

3、创建db.xml文件配置自动扫描

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="com.longteng.utils"></context:component-scan>
    <context:property-placeholder location="config/db.properties"></context:property-placeholder>
</beans>

4、创建测试类

package com.longteng.lesson2;

import com.longteng.utils.DbUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

public class DbTest {
    ApplicationContext context;

    @BeforeClass
    public void initApplication() {
        context = new ClassPathXmlApplicationContext ("db.xml");
    }

    @Test
    public void test() {
        DbUtils dbUtils = context.getBean ("dbUtils", DbUtils.class);

    }
}