标签：userServiceImpl JdbcTemplate Spring void userId User public user

目录

• 什么是 JdbcTemplate
• 环境
• 示例
  • 添加
  • 删除
  • 修改
  • 简单查询
  • 查询返回对象
  • 查询返回集合
  • 批量操作

什么是 JdbcTemplate

Spring 框架对 JDBC 进行封装，使用 JdbcTemplate 方便实现对数据库操作

环境

在Spring配置文件中配置数据库连接池

  <!--引入外部属性文件--> <context:property-placeholder location="classpath:jdbc.properties"/>
    <!--配置连接池-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${prop.driverClass}"/>
        <property name="url" value="${prop.url}"/>
        <property name="username" value="${prop.userName}"/>
        <property name="password" value="${prop.password}"/>
    </bean>

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

prop.driverClass=com.mysql.cj.jdbc.Driver
prop.url=jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8
prop.userName=root
prop.password=123456
#jdbc.properties配置文件

示例

//表
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `userId` int(0) NOT NULL AUTO_INCREMENT,
  `userName` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,
  PRIMARY KEY (`userId`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

package com.fly.spring5.entity;

public class User {

  private int userId;
  private String userName;

  public int getUserId() {
    return userId;
  }

  @Override
  public String toString() {
    return "User{" +
            "userId=" + userId +
            ", userName='" + userName + '\'' +
            '}';
  }

  public void setUserId(int userId) {
    this.userId = userId;
  }

  public String getUserName() {
    return userName;
  }

  public void setUserName(String userName) {
    this.userName = userName;
  }

  public User() {
  }

  public User(int userId, String userName) {
    this.userId = userId;
    this.userName = userName;
  }
}

添加

package com.fly.spring5.dao;

import com.fly.spring5.entity.User;

public interface UserDao {

  //添加方法
  public void add(User user);

}

package com.fly.spring5.dao.impl;

import com.fly.spring5.dao.UserDao;
import com.fly.spring5.entity.User;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import javax.annotation.Resource;

@Repository
public class UserDaoImpl implements UserDao {

  @Resource
  private JdbcTemplate jdbcTemplate;

  @Override
  public void add(User user) {
    String sql = "insert into user values(null,?)";
    jdbcTemplate.update(sql,user.getUserName());
  }

}

package com.fly.spring5.service;

import com.fly.spring5.entity.User;

public interface UserService {
  
  public void add(User user);
  
}

package com.fly.spring5.service.impl;

import com.fly.spring5.dao.UserDao;
import com.fly.spring5.entity.User;
import com.fly.spring5.service.UserService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
public class UserServiceImpl implements UserService {
  
  @Resource
  private UserDao userDao;
  
  @Override
  public void add(User user) {
    userDao.add(user);
  }
}

测试方法

 @Test
  public void test1() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
    User user = new User();
    user.setUserName("张三");
    userServiceImpl.add(user);
  }

删除

  //UserDao
  public void deleteById(Integer userId);

  @Override
  public void deleteById(Integer userId) {
    //UserDaoImpl
    String sql = "delete from user where userId = ?";
    jdbcTemplate.update(sql,userId);
  }

 //UserService
  void deleteById(Integer userId);

 @Override
  public void deleteById(Integer userId) {
    //UserServiceImpl
    userDao.deleteById(userId);
  }

  @Test
  public void test2() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
    userServiceImpl.deleteById(1);
  }

修改

//UserDao
  void update(User user);

  @Override
  public void update(User user) {
    //UserDaoImpl
    String sql = "update user set userName = ? where userId = ?";
    jdbcTemplate.update(sql,user.getUserName(),user.getUserId());
  }

//UserService
  void update(User user);

 @Override
  public void update(User user) {
    //UserServiceImpl
    userDao.update(user);
  }

 @Test
  public void test3() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
   //数据库现在没数据
    User user = new User();
    user.setUserId(3);
    user.setUserName("张三2");
    userServiceImpl.update(user);
  }

简单查询

 //UserDao
  int count();

 @Override
  public int count() {
    //UserDaoImpl
    String sql = "select count(*) from user";
    return jdbcTemplate.queryForObject(sql, Integer.class);
  }

  //UserService
  int count();

  @Override
  public int count() {
    //UserServiceImpl
    return userDao.count();
  }

@Test
  public void test4() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
    int count = userServiceImpl.count();
    System.out.println("count = " + count);
  }

查询返回对象

//UserDao
  User selectById(Integer userId);

@Override
  public User selectById(Integer userId) {
    //UserDaoImpl
    String sql = "select * from user where userId = ?";
    User user = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), userId);
    return user;
  }

//UserService
  User selectById(Integer userId);

 @Override
  public User selectById(Integer userId) {
    //UserServiceImpl
    return userDao.selectById(userId);
  }

 @Test
  public void test5() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
    User user = userServiceImpl.selectById(3);
    System.out.println("user = " + user);
  }

查询返回集合

 //UserDao
  List<User> getUsers();

  @Override
  public List<User> getUsers() {
    //UserDaoImpl
    String sql = "select * from user";
    List<User> userList = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
    return userList;
  }

//UserService
  List<User> getUsers();

 @Override
  public List<User> getUsers() {
    //UserServiceImpl
    return userDao.getUsers();
  }

  @Test
  public void test6() {
    ApplicationContext context =
            new ClassPathXmlApplicationContext("ApplicationContent.xml");
    UserServiceImpl userServiceImpl = context.getBean("userServiceImpl", UserServiceImpl.class);
    List<User> users = userServiceImpl.getUsers();
    System.out.println("users = " + users);
  }

批量操作

标签：userServiceImpl,JdbcTemplate,Spring,void,userId,User,public,user
来源： https://www.cnblogs.com/ftlzypx/p/15514523.html

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