1.需求分析
搭建一个三层架构案例，模拟查询全部学生（学生表）信息，持久层使用JdbcTemplate和Druid技术，使用XML方式进行组件管理！
2.数据库准备
create database studb;
use studb;
CREATE TABLE students (
id INT PRIMARY KEY,
name VARCHAR(50) NOT NULL,
gender VARCHAR(10) NOT NULL,
age INT,
class VARCHAR(50)
);
INSERT INTO students (id, name, gender, age, class)
VALUES
(1, '张三', '男', 20, '高中一班'),
(2, '李四', '男', 19, '高中二班'),
(3, '王五', '女', 18, '高中一班'),
(4, '赵六', '女', 20, '高中三班'),
(5, '刘七', '男', 19, '高中二班'),
(6, '陈八', '女', 18, '高中一班'),
(7, '杨九', '男', 20, '高中三班'),
(8, '吴十', '男', 19, '高中二班');
3.项目准备
a.项目创建
spring-xml-practice-02\
b.pom.xml依赖导入
<dependencies>
<!--spring context依赖-->
<!--当你引入SpringContext依赖之后，表示将Spring的基础依赖引入了-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>6.0.6</version>
</dependency>
<!-- 数据库驱动和连接池-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.25</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.8</version>
</dependency>
<!-- spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>6.0.6</version>
</dependency>
</dependencies>
c.实体类准备
public class Student {
private Integer id;
private String name;
private String gender;
private Integer age;
private String classes;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getClasses() {
return classes;
}
public void setClasses(String classes) {
this.classes = classes;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", name='" + name + '\'' +
", gender='" + gender + '\'' +
", age=" + age +
", classes='" + classes + '\'' +
'}';
}
}
4.三层架构搭建和实现
a.持久层
//接口
public interface StudentDao {
/**
* 查询全部学生数据
* @return
*/
List<Student> queryAll();
}
//实现类
public class StudentDaoImpl implements StudentDao {
private JdbcTemplate jdbcTemplate;
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
/**
* 查询全部学生数据
* @return
*/
@Override
public List<Student> queryAll() {
String sql = "select id , name , age , gender , class as classes from students ;";
/*
query可以返回集合!
BeanPropertyRowMapper就是封装好RowMapper的实现,要求属性名和列名相同即可
*/
List<Student> studentList = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(Student.class));
return studentList;
}
}
b.业务层
//接口
public interface StudentService {
/**
* 查询全部学员业务
* @return
*/
List<Student> findAll();
}
//实现类
public class StudentServiceImpl implements StudentService {
private StudentDao studentDao;
public void setStudentDao(StudentDao studentDao) {
this.studentDao = studentDao;
}
/**
* 查询全部学员业务
* @return
*/
@Override
public List<Student> findAll() {
List<Student> studentList = studentDao.queryAll();
return studentList;
}
}
c.表述层
public class StudentController {
private StudentService studentService;
public void setStudentService(StudentService studentService) {
this.studentService = studentService;
}
public void findAll(){
List<Student> studentList = studentService.findAll();
System.out.println("studentList = " + studentList);
}
}
5.三层架构Ioc配置
<?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 https://www.springframework.org/schema/context/spring-context.xsd">
<!-- 导入外部属性文件 -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 配置数据源 -->
<bean id="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="url" value="${atguigu.url}"/>
<property name="driverClassName" value="${atguigu.driver}"/>
<property name="username" value="${atguigu.username}"/>
<property name="password" value="${atguigu.password}"/>
</bean>
<!-- 配置 JdbcTemplate -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!-- 装配数据源 -->
<property name="dataSource" ref="druidDataSource"/>
</bean>
<bean id="studentDao" class="com.atguigu.dao.impl.StudentDaoImpl">
<property name="jdbcTemplate" ref="jdbcTemplate" />
</bean>
<bean id="studentService" class="com.atguigu.service.impl.StudentServiceImpl">
<property name="studentDao" ref="studentDao" />
</bean>
<bean id="studentController" class="com.atguigu.controller.StudentController">
<property name="studentService" ref="studentService" />
</bean>
</beans>
6.运行测试
public class ControllerTest {
@Test
public void testRun(){
ApplicationContext applicationContext =
new ClassPathXmlApplicationContext("spring-ioc.xml");
StudentController studentController = applicationContext.getBean(StudentController.class);
studentController.findAll();
}
}
XMLIoC方式问题总结
a.注入的属性必须添加setter方法、代码结构乱！
b.配置文件和Java代码分离、编写不是很方便！
c.XML配置文件解析效率低
