Spring JdbcTemplate 基本使用

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JDBTemplate 是 Spring 框架中提供的 — 个模板对象，是对原始繁琐 JDBC API 对象的简单封装。

核心对象

导入依赖坐标

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<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.3.10</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.3.10</version>
</dependency>
<!-- jdbcTemplate 注意要和spring版本一致 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.3.10</version>
</dependency>
<!-- 事务相关 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.3.10</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.26</version>
</dependency>
<!-- 连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.6</version>
</dependency>
<!-- aspect织入（切点表达式需要用到该jar包） -->
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.7</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.2</version>
    <scope>test</scope>
</dependency>

创建 Dao 和 Service 层

实体类

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package com.orginly.domain;

public class User {
    private Integer id;
    private String name;
    private Integer age;

    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 Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Dao

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// 接口
public interface UserDao {
    public List<User> findAll();

    public User find(int id);

    public void updateUser(User user);
}


// 实现类
@Repository
public class UserDaoImpl implements UserDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

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

    /**
     * 查找一条用户信息
     * @param id
     */
    @Override
    public User find(int id) {
        String sql = "select * from user where id = ?";
        return jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), id);
    }

    /**
     * 更新用户信息
     */
    @Override
    public void updateUser(User user) {
        String sql = "update user set name = ?,age = ? where id = ?";
        jdbcTemplate.update(sql, user.getName(), user.getAge(), user.getId());
    }
}

Service

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// 接口
public interface UserService {
    public void findALl();
    public void updateUser();
}

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserDao userDao;

    @Override
    public void findALl() {
        List<User> users = userDao.findAll();
        System.out.println(users.toString());
    }

    @Override
    public void updateUser() {
        User user = userDao.find(2);
        user.setName("li1");
        userDao.updateUser(user);
        System.out.println(user);

    }

}

整合 JdbcTemplate 至 Spring

  1. 新建 jdbc.properties 配置文件

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    jdbc.driverClassName = com.mysql.cj.jdbc.Driver
    jdbc.url = jdbc:mysql://localhost/demo?characterEncoding=UTF-8
    jdbc.username = root
    jdbc.password = 000

  2. 配置 JdbcTemplate 数据源 并将对象创建权交给 IOC 容器

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    <?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
           https://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/context
           https://www.springframework.org/schema/context/spring-context.xsd">

        <!-- 开启 IOC 注解扫描 -->
        <context:component-scan base-package="com.orginly"/>

        <!-- 引入 properties 文件 -->
        <context:property-placeholder location="classpath:jdbc.properties"/>

        <!-- 配置数据源 -->
        <bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
            <property name="driverClassName" value="${jdbc.driverClassName}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
        </bean>

        <!-- jdbcTemplate -->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
            <!-- 绑定数据源 -->
            <property name="dataSource" ref="datasource"/>
        </bean>
    </beans>

整合 Junit4 单元测试

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@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class SpringTest {

    @Autowired
    private UserService userService;

    @Test
    public void test() {
        userService.findALl();
    }
}