JDBC 连接数据库

1.属性配置文件（application.properties）

#jdbc 
spring.datasource.url=jdbc:mysql://localhost:3306/springboot 
spring.datasource.username=root 
spring.datasource.password=bwyp 
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

2.pom.xml 配置maven依赖

<!-- 5.jdbc --> 
<!-- MYSQL --> 
<dependency> 
    <groupId>mysql</groupId> 
    <artifactId>mysql-connector-java</artifactId> 
 </dependency> 
 <!-- Spring Boot JDBC --> 
 <dependency> 
    <groupId>org.springframework.boot</groupId> 
    <artifactId>spring-boot-starter-jdbc</artifactId> 
 </dependency>

User.java

package cn.wuyang.springboot.entity; 
 
public class User { 
 
    private String user_id; 
    private String user_name; 
    public String getUser_id() { 
        return user_id; 
    } 
    @Override 
    public String toString() { 
        return "User [user_id=" + user_id + ", user_name=" + user_name + "]"; 
    } 
    public void setUser_id(String user_id) { 
        this.user_id = user_id; 
    } 
    public String getUser_name() { 
        return user_name; 
    } 
    public void setUser_name(String user_name) { 
        this.user_name = user_name; 
    } 
 
} 

UserController.java

package cn.wuyang.springboot.controller; 
 
import java.util.List; 
 
import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.RestController; 
 
import cn.wuyang.springboot.entity.User; 
import cn.wuyang.springboot.service.UserService; 
 
@RestController 
@RequestMapping("/user") 
public class UserController { 
    private static final Logger logger = LoggerFactory.getLogger(UserController.class); 
 
    @Autowired 
    private UserService userService; 
 
    @RequestMapping("/list") 
    public List<User> getUsers(){ 
        logger.info("从数据库读取Student集合"); 
        return userService.getList(); 
    } 
 
} 

UserService.java

package cn.wuyang.springboot.service; 
 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.util.List; 
 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.jdbc.core.JdbcTemplate; 
import org.springframework.jdbc.core.RowMapper; 
import org.springframework.stereotype.Service; 
 
import cn.wuyang.springboot.entity.User; 
 
@Service 
public class UserService { 
 
    @Autowired 
    private JdbcTemplate jdbcTemplate; 
 
    public List<User> getList(){ 
        String sql = "SELECT *   FROM user_info"; 
        return (List<User>) jdbcTemplate.query(sql, new RowMapper<User>(){ 
            @Override 
            public User mapRow(ResultSet rs, int rowNum) throws SQLException { 
                User user = new User(); 
                user.setUser_id(rs.getString("user_id")); 
                user.setUser_name(rs.getString("user_name")); 
                return user; 
            } 
        }); 
    } 
 
} 

user_info.sql

/* 
Navicat MySQL Data Transfer 
 
Source Server         : Android 
Source Server Version : 50714 
Source Host           : localhost:3306 
Source Database       : springboot 
 
Target Server Type    : MYSQL 
Target Server Version : 50714 
File Encoding         : 65001 
 
Date: 2017-08-17 14:31:02 
*/ 
 
SET FOREIGN_KEY_CHECKS=0; 
 
-- ---------------------------- 
-- Table structure for user_info 
-- ---------------------------- 
DROP TABLE IF EXISTS `user_info`; 
CREATE TABLE `user_info` ( 
  `user_id` varchar(255) COLLATE utf8_bin NOT NULL, 
  `user_name` varchar(255) COLLATE utf8_bin DEFAULT NULL, 
  PRIMARY KEY (`user_id`) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; 
 
-- ---------------------------- 
-- Records of user_info 
-- ---------------------------- 
INSERT INTO `user_info` VALUES ('1', 'wuyang'); 
INSERT INTO `user_info` VALUES ('2', 'admin'); 

然后启动项目，访问地址：http://127.0.0.1:8080/user/list 响应结果如下：

[{"user_id":"1","user_name":"wuyang"},{"user_id":"2","user_name":"admin"}]