Spring Boot中使用JdbcTemplate访问数据库

一 数据源的配置

1 pom中引入JDBC的支持

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

2 关于嵌入式数据库

嵌入式数据库通常用于开发和测试环境，不推荐用于生产环境。Spring Boot提供自动配置的嵌入式数据库有H2、HSQL、Derby，不需要提供任何连接配置就能使用。

如果要引入HSQL，pom配置如下：

<dependency>
    <groupId>org.hsqldb</groupId>
    <artifactId>hsqldb</artifactId>
    <scope>runtime</scope>
</dependency>

3 关于MySQL数据源

如果引入MySQL，在pom.xml中加入下面依赖

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.21</version>
</dependency>

二 实战

1 添加依赖

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.21</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

</dependencies>

2 服务层

1 接口定义

package com.didispace.service;


public interface UserService {

    /**
     * 新增一个用户
     * @param name
     * @param age
     */
    void create(String name, Integer age);

    /**
     * 根据name删除一个用户高
     * @param name
     */
    void deleteByName(String name);

    /**
     * 获取用户总量
     */
    Integer getAllUsers();

    /**
     * 删除所有用户
     */
    void deleteAllUsers();


}

2 接口的实现类

package com.didispace.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public void create(String name, Integer age) {
        jdbcTemplate.update("insert into USER(NAME, AGE) values(?, ?)", name, age);
    }

    @Override
    public void deleteByName(String name) {
        jdbcTemplate.update("delete from USER where NAME = ?", name);
    }

    @Override
    public Integer getAllUsers() {
        return jdbcTemplate.queryForObject("select count(1) from USER", Integer.class);
    }

    @Override
    public void deleteAllUsers() {
        jdbcTemplate.update("delete from USER");
    }
}

3 编写启动类

package com.didispace;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

4 编写测试类

package com.didispace;

import com.didispace.service.UserService;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;


@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(Application.class)
public class ApplicationTests {

    @Autowired
    private UserService userSerivce;

    @Before
    public void setUp() {
        // 准备，清空user表
        userSerivce.deleteAllUsers();
    }

    @Test
    public void test() throws Exception {
        // 插入5个用户
        userSerivce.create("a", 1);
        userSerivce.create("b", 2);
        userSerivce.create("c", 3);
        userSerivce.create("d", 4);
        userSerivce.create("e", 5);

        // 查数据库，应该有5个用户
        Assert.assertEquals(5, userSerivce.getAllUsers().intValue());

        // 删除两个用户
        userSerivce.deleteByName("a");
        userSerivce.deleteByName("e");

        // 查数据库，应该有5个用户
        Assert.assertEquals(3, userSerivce.getAllUsers().intValue());

    }


}

三 运行测试类

运行后，数据库结果如下：

四 参考

http://blog.didispace.com/springbootdata1/