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JdbcTemplate的基本使用 -＞（个人学习记录笔记）

@

目录

  • JdbcTemplate的基本使用
    • 1. 基本使用
      • 1.1 maven导入
      • 1.2 xml配置
      • 1.3 基本使用
      • 1.4 CRUD
    • 2. 抽取dao中的重复代码
      • 2.1 继承写法
      • 2.2 注解写法

JdbcTemplate的基本使用 -＞（个人学习记录笔记）

<packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.23</version>
        </dependency>
    </dependencies>
           

<?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">

    <!-- 配置账户的持久层-->
    <bean id="accountDao" class="xyz.slienceme.dao.impl.AccountDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
<!--        <property name="dataSource" ref="dataSource"/>-->
    </bean>

    <!--配置JdbcTemplate-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </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 name="url" value="jdbc:mysql://localhost:3306/eesy"/>
        <property name="username" value="root"/>
        <property name="password" value="*******"/>
    </bean>
</beans>
           

package xyz.slienceme.jdbctemplate;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;

/**
 * JdbcTemplate的最基本用法
 */
public class JdbcTemplateDemo2 {
    public static void main(String[] args) {
        //1.获取容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        //2.获取对象
        JdbcTemplate jt = ac.getBean("jdbcTemplate",JdbcTemplate.class);
        //3.执行操作
        jt.execute("insert into account(name,money)values('ddd',2222)");
    }
}

           

package xyz.slienceme.jdbctemplate;

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

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

/**
 * JdbcTemplate的CRUD操作
 */
public class JdbcTemplateDemo3 {

    public static void main(String[] args) {
        //1.获取容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        //2.获取对象
        JdbcTemplate jt = ac.getBean("jdbcTemplate",JdbcTemplate.class);
        //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",4567,7);
        //删除
        jt.update("delete from account where id=?",7);
        //查询所有
        List<Account> accounts = jt.query("select * from account where money > ?",new AccountRowMapper(),1000f);
        List<Account> accounts = jt.query("select * from account where money > ?",new BeanPropertyRowMapper<Account>(Account.class),1000f);
        for(Account account : accounts){
            System.out.println(account);
        }
        //查询一个
        List<Account> accounts = jt.query("select * from account where id = ?",new BeanPropertyRowMapper<Account>(Account.class),1);
        System.out.println(accounts.isEmpty()?"没有内容":accounts.get(0));

        //查询返回一行一列（使用聚合函数，但不加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
     * @param rs
     * @param rowNum
     * @return
     * @throws SQLException
     */
    @Override
    public Account mapRow(ResultSet rs, int rowNum) throws SQLException {
        Account account = new Account();
        account.setId(rs.getInt("id"));
        account.setName(rs.getString("name"));
        account.setMoney(rs.getFloat("money"));
        return account;
    }
}
  • 账户的持久层实现类 
package xyz.slienceme.dao.impl;

import xyz.slienceme.dao.IAccountDao;
import xyz.slienceme.domain.Account;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * 账户的持久层实现类
 */
@Repository
public class AccountDaoImpl2 implements IAccountDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;


    @Override
    public Account findAccountById(Integer accountId) {
        List<Account> accounts = jdbcTemplate.query("select * from account where id = ?",new BeanPropertyRowMapper<Account>(Account.class),accountId);
        return accounts.isEmpty()?null:accounts.get(0);
    }

    @Override
    public Account findAccountByName(String accountName) {
        List<Account> accounts = jdbcTemplate.query("select * from account where name = ?",new BeanPropertyRowMapper<Account>(Account.class),accountName);
        if(accounts.isEmpty()){
            return null;
        }
        if(accounts.size()>1){
            throw new RuntimeException("结果集不唯一");
        }
        return accounts.get(0);
    }

    @Override
    public void updateAccount(Account account) {
        jdbcTemplate.update("update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());
    }
}

           

package xyz.slienceme.dao.impl;

import xyz.slienceme.dao.IAccountDao;
import xyz.slienceme.domain.Account;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

import java.util.List;

/**
 * 账户的持久层实现类
 */
public class AccountDaoImpl extends JdbcDaoSupport implements IAccountDao {

    @Override
    public Account findAccountById(Integer accountId) {
        List<Account> accounts = super.getJdbcTemplate().query("select * from account where id = ?",new BeanPropertyRowMapper<Account>(Account.class),accountId);
        return accounts.isEmpty()?null:accounts.get(0);
    }

    @Override
    public Account findAccountByName(String accountName) {
        List<Account> accounts = super.getJdbcTemplate().query("select * from account where name = ?",new BeanPropertyRowMapper<Account>(Account.class),accountName);
        if(accounts.isEmpty()){
            return null;
        }
        if(accounts.size()>1){
            throw new RuntimeException("结果集不唯一");
        }
        return accounts.get(0);
    }

    @Override
    public void updateAccount(Account account) {
        super.getJdbcTemplate().update("update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());
    }
}

           

package xyz.slienceme.dao.impl;

import xyz.slienceme.dao.IAccountDao;
import xyz.slienceme.domain.Account;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * 账户的持久层实现类
 */
@Repository
public class AccountDaoImpl2 implements IAccountDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;


    @Override
    public Account findAccountById(Integer accountId) {
        List<Account> accounts = jdbcTemplate.query("select * from account where id = ?",new BeanPropertyRowMapper<Account>(Account.class),accountId);
        return accounts.isEmpty()?null:accounts.get(0);
    }

    @Override
    public Account findAccountByName(String accountName) {
        List<Account> accounts = jdbcTemplate.query("select * from account where name = ?",new BeanPropertyRowMapper<Account>(Account.class),accountName);
        if(accounts.isEmpty()){
            return null;
        }
        if(accounts.size()>1){
            throw new RuntimeException("结果集不唯一");
        }
        return accounts.get(0);
    }

    @Override
    public void updateAccount(Account account) {
        jdbcTemplate.update("update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());
    }
}
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