Spring_2023_11_20_1

Spring基础依赖

pom依赖

<!-- Spring 基础包括 ：
            Spring-core/Spring-beans/Spring-app/Spring-expression
 -->
<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.20</version>
        </dependency>

核心配置文件(beans.xml/application.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">
    <!--
    UserService 的注册，通过bean标签进行注册
    1.<bean>标签
       1.1 id： 当前bean标签的标识符
       1.2 class 指定注册当前的类（不是接口）
-->
    <bean id="studentService"    class="com.bboy.service.impl.StudentServiceImpl">
        <!-- 属性注入
        1. name 表示在当前类中的属性名
            例如： studentDao 是在StudentServiceImpl 类中的属性名
        2. ref  表示当前属性在spring 核心配置文件中的bean = 》id为 studentDao
        -->
    <property name="studentDao" ref="studentDao"/>
    </bean>
    <bean id="teacherService"    class="com.bboy.service.impl.TeacherServiceImpl">
        <property name="teacherDao" ref="teacherDao"/>
    </bean>

    <bean id="studentDao"  class="com.bboy.dao.impl.StudentDapImpl"/>
    <bean id="teacherDao"  class="com.bboy.dao.impl.TeacherDaoImpl"/>
</beans>

测试 调用核心配置文件里的bean对象

package com.bboy.demo;

import com.bboy.service.StudentService;
import com.bboy.service.TeacherService;
import com.bboy.service.impl.StudentServiceImpl;
import com.bboy.service.impl.TeacherServiceImpl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @类描述：
 * @作者：秦帅
 * @时间：2023/11/20 0020 10:30:48
 */
public class Demo {
    public static void main(String[] args) {
    //- : 使用StudentService
    /*    StudentService service = new StudentServiceImpl();
        service.listStudents();*/
    //-1. 获取Spring容器（通过配置文件获取Spring容器）
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
    //-2. 从容器中获取去bean对象
        StudentService studentService =(StudentService) applicationContext.getBean("studentService");
        studentService.listStudents();
        TeacherService teacherService =(TeacherService) applicationContext.getBean("teacherService");
        teacherService.listTeachers();
    }
}

依赖注入

• 通过service调用dao
• 属性注入： 将StudentDao注入到StudentService

i.在StudentService实现类中设置StudentDao的属性并生成其get与set方法

package com.bboy.service.impl;
import com.bboy.dao.StudentDao;
import com.bboy.pojo.Student;
import com.bboy.service.StudentService;
import java.util.List;
/**
 * @类描述：
 * @作者：秦帅
 * @时间：2023/11/20 0020 10:27:51
 */
public class StudentServiceImpl implements StudentService {
    private StudentDao studentDao;
    public void setStudentDao(StudentDao studentDao){
        this.studentDao=studentDao;
    }
    public StudentDao getStudentDao() {
        return studentDao;
    }
    @Override
    public void listStudents() {
        System.out.println("==============>>StudentServiceImpl");
    }
}

ii. 在spring核心的配置文件中将StudentDao注入到StudentService中

<?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">
    <!--
    UserService 的注册，通过bean标签进行注册
    1.<bean>标签
       1.1 id： 当前bean标签的标识符
       1.2 class 指定注册当前的类（不是接口）
-->
    <bean id="studentService"    class="com.bboy.service.impl.StudentServiceImpl">
        <!-- 属性注入
        1. name 表示在当前类中的属性名
            例如： studentDao 是在StudentServiceImpl 类中的属性名
        2. ref  表示当前属性在spring 核心配置文件中的bean = 》id为 studentDao
        -->
    <property name="studentDao" ref="studentDao"/>
    </bean>

    <bean id="teacherService"    class="com.bboy.service.impl.TeacherServiceImpl">
        <property name="teacherDao" ref="teacherDao"/>
    </bean>

    <bean id="studentDao"  class="com.bboy.dao.impl.StudentDapImpl"/>
    <bean id="teacherDao"  class="com.bboy.dao.impl.TeacherDaoImpl"/>
</beans>