Spring入门1

注解方式

注解种类

组件

Component

@Component("normal")：指定bean id
如下为细分组件，没有语言层面的区别，仅仅为了区分所在分层

Service：服务层组件

Repository：持久层组件

Controller：控制器组件

自动装配Autowired

默认为一定要装配

Qualifier：指定限定符

@Qualifier("normal")

获取上下文方式

通过spring-test包的注解
@ContextConfiguration(classes = AppConfig.class)

主函数入口与代码解耦：新建配置类

@Configuration：新建一个配置类，添加此注解

package com.verfallen.demo.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages = "com.verfallen.demo")
public class AppConfig {
}

扫描组件：需要写好包名，否则只去AppConfig所在包下寻找

测试方法

Junit + Spring-test

package com.verfallen.demo.controller;

import com.verfallen.demo.config.AppConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class)
public class ControllerTest {
    @Autowired
    private UserControl userControl;

    @Test
    public void test() {
        userControl.add();
    }
}

main方法：注解与xml

package com.verfallen.demo;

import com.verfallen.demo.controller.UserControl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class WebTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationcontext.xml");
//        ApplicationContext context = new AnnotationConfigApplicationContext("com.verfallen.demo");
        UserControl userControl = (UserControl) context.getBean("userControlNormal");
        userControl.add();
    }
}

xml方式

配置文件

配置bean，可以构造属性设置注入

<?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">

    <bean id="daoNormal" class="demo.dao.impl.UserDaoNormal"></bean>

    <bean id="daoFestival" class="demo.dao.impl.UserDaoFestival"></bean>

    <bean id="service" class="demo.service.impl.UserServiceNormal">
        <constructor-arg name="userDao" ref="daoFestival"/>
    </bean>

    <bean id="controller" class="demo.controller.impl.UserControlNormal">
        <property name="userService" ref="service"></property>
    </bean>
</beans>

获取上下文方式

package demo;

import demo.controller.UserControl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class WebTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationcontext.xml");
//        ApplicationContext context = new AnnotationConfigApplicationContext("com.verfallen.demo");
        UserControl userControl = (UserControl) context.getBean("controller");
        userControl.add();
    }
}

参考

千峰教育视频