SSM学习笔记二(SpringIoC和DI注解开发)

一：Spring相关API

笔记二程序源码下载

applicationContext：接口类型，代表应用上下文，可以通过其实例获得 Spring 容器中的 Bean 对象

ApplicationContext的实现类

1）ClassPathXmlApplicationContext

​ 它是从类的根路径下加载配置文件 推荐使用这种

2）FileSystemXmlApplicationContext

​ 它是从磁盘路径上加载配置文件，配置文件可以在磁盘的任意位置。

3）AnnotationConfigApplicationContext

​ 当使用注解配置容器对象时，需要使用此类来创建 spring 容器。它用来读取注解。

4.3 getBean()方法使用

//id的方式
public Object getBean(String name) throws BeansException {
    
      
	assertBeanFactoryActive();   
	return getBeanFactory().getBean(name);
}
//类型方式
public <T> T getBean(Class<T> requiredType) throws BeansException {
    
       			    	assertBeanFactoryActive();
	return getBeanFactory().getBean(requiredType);
}

其中，当参数的数据类型是字符串时，表示根据Bean的id从容器中获得Bean实例，返回是Object，需要强转。

当参数的数据类型是Class类型时，表示根据类型从容器中匹配Bean实例，当容器中相同类型的Bean有多个时，则此方法会报错

getBean()方法使用

package com.itcast.demo;
import com.itcast.services.Userservices;
import com.itcast.services.impl.userservicesimpl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserController {
    
    
    public static void main(String[] args) {
    
    
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        //Userservices userservices = (Userservices) app.getBean("UserServices");
        Userservices userservices =app.getBean(Userservices.class);
        userservices.save();
    }
}

运行结果：

Spring配置数据源(连接池)

配置数据源的步骤：

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>org.example</groupId>
    <artifactId>learningSpringAnno</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <!-- Druid连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

如果遇到报红的话，右键pom.xml的maven，然后点击重新加载maven项目即可

新建测试类来测试数据源

datasourceTest.java

package com.itcast.test;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;

import java.sql.Connection;

public class datasourceTest {
    
    
    @Test
    public void testC3P0() throws Exception {
    
    
        //创建数据源
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //设置数据库连接参数
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUser("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
}

运行结果：

添加testDruid()方法
datasourceTest.java

package com.itcast.test;
import com.alibaba.druid.pool.DruidDataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;

import java.sql.Connection;

public class datasourceTest {
    
    
    @Test
    public void testC3P0() throws Exception {
    
    
        //创建数据源
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //设置数据库连接参数
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUser("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
    @Test
    public void testDruid() throws Exception {
    
    
        //创建数据源
        DruidDataSource dataSource = new DruidDataSource();
        //设置数据库连接参数
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUsername("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
}

使用配置文件的方式配置jdbc连接
1：在resource包下添加jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3308/manage
jdbc.username=root
jdbc.password=yww1352465324

添加测试代码testC3P0Properties()方法:

package com.itcast.test;
import com.alibaba.druid.pool.DruidDataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;

import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ResourceBundle;

public class datasourceTest {
    
    
    @Test
    public void testC3P0() throws Exception {
    
    
        //创建数据源
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //设置数据库连接参数
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUser("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
/*    @Test
    public void testDruid() throws Exception {
        //创建数据源
        DruidDataSource dataSource = new DruidDataSource();
        //设置数据库连接参数
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUsername("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }*/
    @Test
    public void testC3P0Properties() throws Exception {
    
    
        //读取配置文件
        //资源绑定
        ResourceBundle resourceBundle = ResourceBundle.getBundle("jdbc");
        //获取驱动
        String driver = resourceBundle.getString("jdbc.driver");
        String url = resourceBundle.getString("jdbc.url");
        String username = resourceBundle.getString("jdbc.username");
        String password = resourceBundle.getString("jdbc.password");
        //创建数据源对象，设置连接参数
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(username);
        dataSource.setPassword(password);
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
}

运行结果：打印Connection连接对象

Spring配置数据源

第一步：配置Spring
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>org.example</groupId>
    <artifactId>learningSpringAnno</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <!-- Druid连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.2</version>
        </dependency>
    </dependencies>
</project>

第二步：配置bean
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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <!--把set方法后面的东西作为name的参数,把开头大写改为小写-->
            <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
            <property name="jdbcUrl" value="jdbc:mysql://localhost:3308/manage"></property>
            <property name="user" value="root"></property>
            <property name="password" value="yww1352465324"></property>
        </bean>
</beans>

第三步：添加测试方法testSpringdataSource()

package com.itcast.test;
import com.alibaba.druid.pool.DruidDataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ResourceBundle;

public class datasourceTest {
    
    
    @Test
    public void testC3P0() throws Exception {
    
    
        //创建数据源
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //设置数据库连接参数
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUser("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
/*    @Test
    public void testDruid() throws Exception {
        //创建数据源
        DruidDataSource dataSource = new DruidDataSource();
        //设置数据库连接参数
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3308/manage?useSSL=false");
        dataSource.setUsername("root");
        dataSource.setPassword("yww1352465324");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }*/
    @Test
    public void testC3P0Properties() throws Exception {
    
    
        //读取配置文件
        //资源绑定
        ResourceBundle resourceBundle = ResourceBundle.getBundle("jdbc");
        //获取驱动
        String driver = resourceBundle.getString("jdbc.driver");
        String url = resourceBundle.getString("jdbc.url");
        String username = resourceBundle.getString("jdbc.username");
        String password = resourceBundle.getString("jdbc.password");
        //创建数据源对象，设置连接参数
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(username);
        dataSource.setPassword(password);
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
    @Test
    public void testSpringdataSource() throws SQLException {
    
    
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        DataSource dataSource = (DataSource) applicationContext.getBean("dataSource");
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
}

运行结果：

抽取jdbc配置文件

applicationContext.xml加载jdbc.properties配置文件获得连接信息。

首先，需要引入context命名空间和约束路径：

命名空间：xmlns:context=“http://www.springframework.org/schema/context”

约束路径：http://www.springframework.org/schema/context
​

​ http://www.springframework.org/schema/context/spring-context.xsd

<context:property-placeholder location="classpath:jdbc.properties"/>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="${jdbc.driver}"/>
    <property name="jdbcUrl" value="${jdbc.url}"/>
    <property name="user" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>

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">
    <!--加载外部的properties文件-->
    <context:property-placeholder location="classpath:jdbc.properties"/>

<!--    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            &lt;!&ndash;把set方法后面的东西作为name的参数,把开头大写改为小写&ndash;&gt;
            <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
            <property name="jdbcUrl" value="jdbc:mysql://localhost:3308/manage"></property>
            <property name="user" value="root"></property>
            <property name="password" value="yww1352465324"></property>
    </bean>-->
    <!--使用Spring表达式-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!--把set方法后面的东西作为name的参数,把开头大写改为小写-->
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
</beans>

测试方法代码:

    @Test
    public void testSpringdataSource() throws SQLException {
    
    
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        DataSource dataSource = (DataSource) applicationContext.getBean("dataSource");
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

运行结果：打印出了Connection对象

Spring注解开发

Spring是轻代码而重配置的框架，配置比较繁重，影响开发效率，所以注解开发是一种趋势，注解代替xml配置文件可以简化配置，提高开发效率。
Spring原始注解主要是替代的配置

注解	说明
@Component	使用在类上用于实例化Bean(加到dao对应的Impl实现类上和加到services对应的Impl实现类上)
@Controller	使用在web层类上用于实例化Bean
@Service	使用在service层类上用于实例化Bean
@Repository	使用在dao层类上用于实例化Bean
@Autowired	使用在字段上用于根据类型依赖注入(尽量和Qualifier一起使用,这样当Spring容器中有多个相同类型的bean的时候不会混乱)加到要注入services层的成员变量上
@Qualifier	结合@Autowired一起使用用于根据名称(id)进行依赖注入
@Resource	相当于@Autowired+@Qualifier，按照名称进行注入
@Value	注入普通属性
@Scope	标注Bean的作用范围
@PostConstruct	使用在方法上标注该方法是Bean的初始化方法
@PreDestroy	使用在方法上标注该方法是Bean的销毁方法

实例：
项目结构：

dao层:
UserDao.java

package com.itheima.dao;

public interface UserDao {
    
    
    public void save();
}

UserDao.java对应的实现类UserDaoImpl.java

package com.itheima.dao.impl;

import com.itheima.dao.UserDao;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;

//<bean id="userDao" class="com.itheima.dao.impl.UserDaoImpl"></bean>
//@Component("userDao")
@Repository("userDao")
public class UserDaoImpl implements UserDao {
    
    
    public void save() {
    
    
        System.out.println("save running...");
    }
}

services层UserService接口

package com.itheima.service;

public interface UserService {
    
    
    public void save();
}

UserService接口的实现类UserServiceImpl.java

package com.itheima.service.impl;

import com.itheima.dao.UserDao;
import com.itheima.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.Resource;

//<bean id="userService" class="com.itheima.service.impl.UserServiceImpl">
//@Component("userService")
@Service("userService")
//@Scope("prototype")
@Scope("singleton")
public class UserServiceImpl implements UserService {
    
    

    @Value("${jdbc.driver}")
    private String driver;

    //<property name="userDao" ref="userDao"></property>
    //@Autowired //按照数据类型从Spring容器中进行匹配的
    //@Qualifier("userDao")  //是按照id值从容器中进行匹配的 但是主要此处@Qualifier结合@Autowired一起使用
    @Resource(name="userDao") //@Resource相当于@Qualifier+@Autowired,Repository和Resource对应,一个用来定义,一个用来注入
    //这里往service层注入dao层的userDao
    private UserDao userDao;

    public void save() {
    
    
        System.out.println(driver);
        userDao.save();
    }

    @PostConstruct
    public void init(){
    
    
        System.out.println("Service对象的初始化方法");
    }

    @PreDestroy
    public void destory(){
    
    
        System.out.println("Service对象的销毁方法");
    }

}

web层UserController.java

package com.itheima.web;

import com.itheima.cofig.SpringCofiguration;
import com.itheima.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserController {
    
    

    public static void main(String[] args) {
    
    
        //ClassPathXmlApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        ApplicationContext app = new AnnotationConfigApplicationContext(SpringCofiguration.class);
        UserService userService = app.getBean(UserService.class);
        userService.save();
    }

}

运行结果:
可以看到通过注解注入的方式，services层调用了dao层的save()方法

注意事项：如果使用的是Component的方式+ @Autowired 和@Qualifier(“userDao”) 的方式，那么在applicationContext.xml中要添加组件扫描

Spring新注解

使用上面的注解还不能全部替代xml配置文件，还需要使用注解替代的配置如下：

非自定义的Bean的配置：

加载properties文件的配置：context:property-placeholder

组件扫描的配置：context:component-scan

引入其他文件：

注解	说明
@Configuration	用于指定当前类是一个 Spring 配置类，当创建容器时会从该类上加载注解
@ComponentScan	用于指定 Spring 在初始化容器时要扫描的包。 作用和在 Spring 的 xml 配置文件中的 <context:component-scan base-package=“com.itheima”/>一样
@Bean	使用在方法上，标注将该方法的返回值存储到 Spring 容器中
@PropertySource	用于加载.properties 文件中的配置
@Import	用于导入其他配置类

SpringCofiguration.java

package com.itheima.cofig;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.*;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;

//标志该类是Spring的核心配置类
@Configuration
//<context:component-scan base-package="com.itheima"/>
@ComponentScan("com.itheima")
//<import resource=""/>
@Import({
    
    DataSourceConfiguration.class})
public class SpringCofiguration {
    
    

}

DataSourceConfiguration.java

package com.itheima.cofig;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;

//<context:property-placeholder location="classpath:jdbc.properties"/>
@PropertySource("classpath:jdbc.properties")
public class DataSourceConfiguration {
    
    

    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;

    @Bean("dataSource")  //Spring会将当前方法的返回值以指定名称存储到Spring容器中
    public DataSource getDataSource() throws PropertyVetoException {
    
    
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(username);
        dataSource.setPassword(password);
        return dataSource;
    }

}

运行结果：

Spring整合Junit

原始Junit测试Spring的问题

在测试类中，每个测试方法都有以下两行代码：

 ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
 IAccountService as = ac.getBean("accountService",IAccountService.class);

这两行代码的作用是获取容器，如果不写的话，直接会提示空指针异常。所以又不能轻易删掉。

上述问题解决思路

让SpringJunit负责创建Spring容器，但是需要将配置文件的名称告诉它

将需要进行测试Bean直接在测试类中进行注入

Spring集成Junit步骤

①导入spring集成Junit的坐标

②使用@Runwith注解替换原来的运行期

③使用@ContextConfiguration指定配置文件或配置类

④使用@Autowired注入需要测试的对象

⑤创建测试方法进行测试

①导入spring集成Junit的坐标

<!--此处需要注意的是，spring5 及以上版本要求 junit 的版本必须是 4.12 及以上-->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.0.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>

②使用@Runwith注解替换原来的运行期

@RunWith(SpringJUnit4ClassRunner.class)
public class SpringJunitTest {
    
    
}

③使用@ContextConfiguration指定配置文件或配置类

@RunWith(SpringJUnit4ClassRunner.class)
//加载spring核心配置文件
//@ContextConfiguration(value = {"classpath:applicationContext.xml"})
//加载spring核心配置类
@ContextConfiguration(classes = {
    
    SpringConfiguration.class})
public class SpringJunitTest {
    
    
}

④使用@Autowired注入需要测试的对象

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {
    
    SpringConfiguration.class})
public class SpringJunitTest {
    
    
    @Autowired
    private UserService userService;
}

⑤创建测试方法进行测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {
    
    SpringConfiguration.class})public class SpringJunitTest {
    
    
    @Autowired
    private UserService userService;
    @Test
    public void testUserService(){
    
    
   	 userService.save();
    }
}

pom.xml代码如下:

<?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>org.example</groupId>
    <artifactId>learningSpringAnno</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <!-- Druid连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.3.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

SpringJunitTest.java测试类

package com.itheima.test;

import com.itheima.cofig.SpringCofiguration;
import com.itheima.service.UserService;
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;

import javax.sql.DataSource;
import java.sql.SQLException;


//使用Spring提供的一个内核去跑,该类帮忙完成了许多的工作，包括配置文件加载和Spring容器的创建
@RunWith(SpringJUnit4ClassRunner.class)
//指定配置文件的位置
//@ContextConfiguration("classpath:applicationContext.xml")
//使用全注解的方式来加载配置文件,通过使用核心配置类来作为参数
@ContextConfiguration(classes = {
    
    SpringCofiguration.class})
public class SpringJunitTest {
    
    

    @Autowired
    //该对象在容器当中,通过Autowired可以向该对象的成员变量中注入,注入成功之后则可以测试该对象
    private UserService userService;

    @Autowired
    private DataSource dataSource;

    @Test
    public void test1() throws SQLException {
    
    
        userService.save();
        System.out.println(dataSource.getConnection());
    }

}

运行结果：