Spring(注解方式)简单入门

1.pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>net.cybcclass</groupId>
    <artifactId>cyb_spring</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>5.0.7.RELEASE</version>
        </dependency>


        <!-- 单元测试Junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>cyb_spring</finalName>
        <plugins>
            <!-- 配置Maven的JDK编译级别 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.2</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>

 2.applicationContext.xml

<?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="video" class="net.cybclass.sp.domain.Video">
        <property name="id" value="9"></property>
        <property name="title" value="Spring5.X课程"></property>
    </bean>

    <!--<bean id="UserService" class="net.cybclass.sp.service.UserServiceImpl"></bean>-->
    <context:component-scan base-package="net.cybclass.sp.service"></context:component-scan>
</beans>

3.UserService.java

package net.cybclass.sp.service;

/**
 * @author: wangxiaobo
 * @create: 2020-10-03 15:44
 **/
public interface UserService {
    void speak();
}

4.UserServiceImpl.java

其他注解：@Component、@Controller、@Service、@Repository

package net.cybclass.sp.service;

import org.springframework.stereotype.Service;

/**
 * @author: wangxiaobo
 * @create: 2020-10-03 15:44
 **/
@Service
public class UserServiceImpl implements UserService {
    @Override
    public void speak() {
        System.out.println("王晓波博客：qq_34709784");
    }
}

5.TestUserService.java

package net.cybclass.sp.test;

import net.cybclass.sp.service.UserService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author: wangxiaobo
 * @create: 2020-10-03 15:49
 **/
public class TestUserService {
    @Test
    public void TestIoc() {
//        ApplicationContext context = new ClassPathXmlApplicationContext ("applicationContext.xml");
//        // 方式一
//        UserService service1 = context.getBean(UserService.class);
//        service1.speak();
//        // 方式二
//        UserService service2 = (UserService)context.getBean("UserService");
//        service2.speak();
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService service1 = context.getBean(UserService.class);
        service1.speak();
    }

运行：