JdbcTemplate的CRUD操作

Posted 2021-03-11 lijiahaoAA

实体类

package com.itheima.domain;

import java.io.Serializable;

/**
 * @Author: lijiahao
 * @Description: 账户的实体类
 * @Data: Create in 1:32 2020/2/9
 * @Modified By:
 */
public class Account implements Serializable {

    private Integer id;
    private String name;
    private Float money;

    @Override
    public String toString() {
        return "account{" +
                "id=" + id +
                ", name=‘" + name + ‘‘‘ +
                ", money=" + money +
                ‘}‘;
    }

    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 Float getMoney() {
        return money;
    }

    public void setMoney(Float money) {
        this.money = money;
    }
}

JdbcTemplate测试类

package com.itheima.jdbctemplate;

import com.itheima.domain.Account;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

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

/**
 * @Author: lijiahao
 * @Description: jdbctemplate的最基本用法：CRUD
 * @Data: Create in 1:34 2020/2/9
 * @Modified By:
 */
public class JdbcTemplateDemo3 {
    public static void main(String[] args) {

        //1.获取容器
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("bean.xml");
        //2.获取对象
        JdbcTemplate jt = (JdbcTemplate) applicationContext.getBean("jdbcTemplate");
        //3.执行操作

        //保存
        jt.update("insert into account (name,money) values (?,?)","eee",3333f);
        //更新
        jt.update("update account set name=? ,money=? where id=?","test",1523f,7);
        //删除
        jt.update("delete from account where id=?", 8);

        //查询所有
        //List<Account> accountList = jt.query("select * from account where money > ?",new AccountRowMapper() , 1000f);
        List<Account> accountList = jt.query("select * from account where money > ?",new BeanPropertyRowMapper<Account>(Account.class), 1000f);
        for(Account account : accountList){
            //System.out.println(account);
        }
        //查询一个
        List<Account> accountList1 = jt.query("select * from account where id = ?",new BeanPropertyRowMapper<Account>(Account.class), 1);
        System.out.println(accountList1.isEmpty()?"没有内容":accountList1.get(0));
        //查询返回一行一列（使用聚合函数，但不使用group by 子句）
        Long count = jt.queryForObject("select count(*) from account where money > ?",Long.class, 1000f);
        System.out.println(count);
    }
}

//定义Account的封装策略
class AccountRowMapper implements RowMapper<Account>{

    //把结果集中的数据封装到Account中，然后由spring把每个Account加到集合中
    public Account mapRow(ResultSet resultSet, int rowNum) throws SQLException {
        Account account = new Account();
        account.setId(resultSet.getInt("id"));
        account.setMoney(resultSet.getFloat("money"));
        account.setName(resultSet.getString("name"));
        return account;
    }
}

配置文件bean.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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--配置JdbTemplate-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!--配置数据源-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/eesy?serverTimezone=Asia/Shanghai&amp;characterEncoding=utf8&amp;useSSL=false"></property>
        <property name="username" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
</beans>