Spring--连接数据库

Spring提供了JdbcTemplate模板类

依赖的引入：

i. Spring-context

ii. Spring-jdbc

iii. Mysql

iv. dbcp(连接池)

        <!--spring基础依赖-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.20</version>
        </dependency>
        <!--spring连接数据库-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.30</version>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.29</version>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.30</version>
        </dependency>
        <!--数据库连接池-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.11.0</version>
        </dependency>

创建实体类对象（表对应的对象）

package com.bboy.pojo;

import lombok.Data;

@Data
/*
 * @类描述：
 * @作者：秦帅
 * @时间：2023/11/22 0022 17:39:54
 */
public class Student {
    private int id ;
    private String name ;
    private String birth ;
    private String sex ;
    private String password ;
}

创建dao层的内容

i. StudentDao

package com.bboy.dao;

import com.bboy.pojo.Student;

import java.util.List;

public interface StudentDao {
    public List<Student> listStudents();
}

ii. StudentDaoImpl 需要继承JdbcDaoSupport类

package com.neuedu.dao.impl;

import com.neuedu.dao.StudentDao;
import com.neuedu.pojo.Student;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class StudentDaoImpl implements StudentDao {
    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {

        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public List<Student> listStudents() {
        List<Student> lists = new ArrayList<>();
        //-使用jdbc模板执行sql语句
        jdbcTemplate.query("select * from t_student", new RowMapper<Student>() {
            @Override
            public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
                Student stu = new Student();
                stu.setId(rs.getInt("id"));
                stu.setName(rs.getString("name"));
                stu.setBirth(rs.getString("birth"));
                stu.setSex(rs.getString("sex"));
                lists.add(stu);
                return stu;
            }
        });
        return lists;
    }
}

核心配置文件中进行配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!--配置数据源-->
    <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/qinmanage"/>
        <property name="username" value="root"/>
        <property name="password" value="127003"/>
    </bean>
    <!--将数据源配置到JdbcTemplate模板中-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--将JdbcTemplate注入到dao中-->
    <bean id="studentDao" class="com.bboy.dao.impl.StudentDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>
</beans>

测试类

package com.bboy.demo;

import com.bboy.dao.StudentDao;
import com.bboy.pojo.Student;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

/**
 * @类描述：
 * @作者：秦帅
 * @时间：2023/11/22 0022 18:06:46
 */
public class Demo {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        StudentDao studentDao = (StudentDao) context.getBean("studentDao");
        List<Student> stus = studentDao.listStudents();
        System.out.println(stus);
    }
}

运行结果