spring boot使用JDBCTemplate访问Mysql

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发布于 2019-03-19 07:47:20

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每一个成功人士的背后，必定曾经做出过勇敢而又孤独的决定。

放弃不难，但坚持很酷~

本文主要介绍spring boot如何使用JDBCTemplate来访问Mysql，对单表做简单的增删改查操作。环境说明：

IntelliJ IDEA
JDK 1.8
Maven 3.5.0
Mysql

一、初始化mysql

创建数据库，创建数据表，并生成一些测试数据。

CREATE DATABASE spring_boot_study;
USE spring_boot_study;
DROP TABLE IF EXISTS `user_manage`;
CREATE TABLE `user_manage` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(20) NOT NULL,
  `password` varchar(20) NOT NULL,
  `telPhone` varchar(20) NOT NULL,
  `cdate` datetime DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `user_manage` VALUES ('1', 'admin', '12345678', '1761581****', '2017-09-11 15:03:49');
INSERT INTO `user_manage` VALUES ('2', 'tom', '12345678', '178********', '2017-09-17 10:19:06');
INSERT INTO `user_manage` VALUES ('3', 'seven', 'admin111', '176********', '2017-10-27 20:33:40');
INSERT INTO `user_manage` VALUES ('4', 'Mary', '11111111', '1786281****', '2017-12-12 16:33:53');

二、spring boot配置

1. application.yml

根据个人喜好选择配置文件的类型，在这里我选择配置application.yml，主要对datasource进行一些配置说明。

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/spring_boot_study?allowMultiQueries=true&serverTimezone=GMT%2B8
    username: root
    password: root
server:
  port: 8081
  servlet:
    context-path: /spring-boot-study

2. pom.xml

至少引入下面三个依赖：

<!--引入JDBC的依赖-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!--引入mysql连接-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<!--引入web依赖,可以使用@RequestMapping，@RestController等注解-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

三、具体编码

我们如果要制作API接口的话，需要编写四个层：实体（Entity）层；DAO层；Service层；Controller层。

1. 实体（Entity）层：

public class UsersEntity {
    private int id;
    private String userName;
    private String password;
    private String telPhone;
    private String cdate;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

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

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getTelPhone() {
        return telPhone;
    }

    public void setTelPhone(String telPhone) {
        this.telPhone = telPhone;
    }

    public String getCdate() {
        return cdate;
    }

    public void setCdate(String cdate) {
        this.cdate = cdate;
    }

    @Override
    public String toString() {
        return "UsersEntity{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                ", telPhone='" + telPhone + '\'' +
                ", cdate='" + cdate + '\'' +
                '}';
    }
}

2. DAO层

由接口和实现类组成：

public interface UsersDAO {
    /**
     * @description: 获取表中所有信息。
     * @return: java.util.List<com.study.spring.entity.UsersEntity>
     */
    List<UsersEntity> usersList();

    /**
     * @description: 通过name来查询信息
     * @param: name
     * @return: com.study.spring.entity.UsersEntity
     */
    UsersEntity findUserOne(String name);

    /**
     * @description: 向表中插入一条数据
     * @param: usersEntity
     * @return: void
     */
    void saveUser(UsersEntity usersEntity);

    /**
     * @description: 更新表中单条数据
     * @param: usersEntity
     * @return: void
     */
    void updateUser(UsersEntity usersEntity);

    /**
     * @description: 删除表中单条数据
     * @param: name
     * @return: void
     */
    void removeUser(String name);
}

实现类：

@Repository
public class UsersDaoImpl implements UsersDAO {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public List<UsersEntity> usersList() {
        List<UsersEntity> list = jdbcTemplate.query("select * from user_manage", new Object[]{}, new BeanPropertyRowMapper(UsersEntity.class));
        return list;
    }

    @Override
    public UsersEntity findUserOne(String name) {
        List<UsersEntity> list = jdbcTemplate.query("select * from user_manage where user_name = ?", new Object[]{name}, new BeanPropertyRowMapper(UsersEntity.class));
        if (list != null && list.size() > 0) {
            UsersEntity usersEntity = list.get(0);
            return usersEntity;
        } else {
            return null;
        }
    }

    @Override
    public void saveUser(UsersEntity usersEntity) {
        jdbcTemplate.update("insert into user_manage(user_name, password, telPhone) values(?, ?, ?)",
                usersEntity.getUserName(), usersEntity.getPassword(), usersEntity.getTelPhone());
    }

    @Override
    public void updateUser(UsersEntity usersEntity) {
        jdbcTemplate.update("UPDATE user_manage SET password=?, telPhone=? WHERE user_name=?",
                usersEntity.getPassword(), usersEntity.getTelPhone(), usersEntity.getUserName());
    }

    @Override
    public void removeUser(String name) {
        jdbcTemplate.update("DELETE FROM user_manage WHERE user_name = ?", name);
    }
}

说明：

需要在DAO层的实现类里面加入注解@Repository
通过注解@Autowired来引用JdbcTemplate

3. Service层

由接口与实现类组成：

public interface UsersService {

    /**
     * @description: 获取表中所有信息。
     * @return: java.util.List<com.study.spring.entity.UsersEntity>
     */
    List<UsersEntity> usersList();

    /**
     * @description: 通过name来查询信息
     * @param: name
     * @return: com.study.spring.entity.UsersEntity
     */
    UsersEntity findUserOne(String name);

    /**
     * @description: 向表中插入一条数据
     * @param: usersEntity
     * @return: void
     */
    void saveUser(UsersEntity usersEntity);

    /**
     * @description: 更新表中单条数据
     * @param: usersEntity
     * @return: void
     */
    void updateUser(UsersEntity usersEntity);

    /**
     * @description: 删除表中单条数据
     * @param: name
     * @return: void
     */
    void removeUser(String name);
}

实现类：

@Service
public class UsersServiceImpl implements UsersService {

    @Autowired
    private UsersDAO usersDao;

    @Override
    public List<UsersEntity> usersList() {
        return usersDao.usersList();
    }

    @Override
    public UsersEntity findUserOne(String name) {
        return usersDao.findUserOne(name);
    }

    @Override
    public void saveUser(UsersEntity usersEntity) {
        usersDao.saveUser(usersEntity);
    }

    @Override
    public void updateUser(UsersEntity usersEntity) {
        usersDao.updateUser(usersEntity);
    }

    @Override
    public void removeUser(String name) {
        usersDao.removeUser(name);
    }
}

说明：

需要在Serivice层的实现类里面加入注解@Service
通过注解@Autowired来引用DAO层的接口UsersDAO

4. Controller层

@RestController
@RequestMapping("users")
public class UsersController {

    @Autowired
    private UsersService usersService;

    /**
     * @description: 获取表中所有信息。
     * @return: java.util.List<com.study.spring.entity.UsersEntity>
     */
    @RequestMapping(value = "list", method = RequestMethod.GET)
    public List<UsersEntity> list() {
        return usersService.usersList();
    }

    /**
     * @description: 通过name来查询信息
     * @param: name
     * @return: com.study.spring.entity.UsersEntity
     */
    @RequestMapping(value = "{name}", method = RequestMethod.GET)
    public UsersEntity findUserOne(@PathVariable("name") String name){
        return usersService.findUserOne(name);
    }

    /**
     * @description: 向表中插入一条数据
     * @param: usersEntity
     * @return: java.util.Map<java.lang.String,java.lang.Boolean>
     */
    @RequestMapping(value = "save", method = RequestMethod.POST)
    public Map<String,Boolean> save(UsersEntity usersEntity) {
        Map<String,Boolean> map = new HashMap<>();
        try {
            usersService.saveUser(usersEntity);
            map.put("status",true);
        } catch (Exception e) {
            map.put("status",false);
        }
        return map;
    }

    /**
     * @description: 更新表中数据
     * @return: void
     */
    @RequestMapping(value = "update", method = RequestMethod.PUT)
    public Map<String,Boolean> update(UsersEntity usersEntity) {
        Map<String,Boolean> map = new HashMap<>();
        try {
            usersService.updateUser(usersEntity);
            map.put("status",true);
        } catch (Exception e) {
            map.put("status",false);
        }
        return map;
    }

    @RequestMapping(value = "remove", method = RequestMethod.DELETE)
    public Map<String,Boolean> remove(@RequestParam(value = "userName",required = true) String name) {
        Map<String,Boolean> map = new HashMap<>();
        try {
            usersService.removeUser(name);
            map.put("status",true);
        } catch (Exception e) {
            e.printStackTrace();
            map.put("status",false);
        }
        return map;
    }
}