03SpringBoot用JdbcTemplates访问Mysql

03SpringBoot用JdbcTemplates访问Mysql

• 文章指导
• 学习笔记
• 学习代码

1. 初始化mysql

-- create table `account`
DROP TABLE `account` IF EXISTS
CREATE TABLE `account` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) NOT NULL,
  `money` double DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
INSERT INTO `account` VALUES ('1', 'aaa', '1000');
INSERT INTO `account` VALUES ('2', 'bbb', '1000');
INSERT INTO `account` VALUES ('3', 'ccc', '1000');

2. 引入依赖

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

<!--引入mysql连接类和连接池-->

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

<dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>druid</artifactId>
	<version>1.0.29</version>
</dependency>

<!--开启web-->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

3. 在application.properties文件配置mysql的驱动类，数据库地址，数据库账号、密码信息。

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=123456

4. 实体类

public class Account {
    private int id ;
    private String name ;
    private double money;

....省略了getter. setter

}

5. dao层

public interface IAccountDAO {
    int add(Account account);

    int update(Account account);

    int delete(int id);

    Account findAccountById(int id);

    List<Account> findAccountList();
}

6. dao具体的实现类

@Repository  // 注意加这个注解
public class AccountDaoImpl implements IAccountDAO {

    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Override
    public int add(Account account) {
        return jdbcTemplate.update("insert into account(name, money) values(?, ?)",
              account.getName(),account.getMoney());

    }

    @Override
    public int update(Account account) {
        return jdbcTemplate.update("UPDATE  account SET NAME=? ,money=? WHERE id=?",
                account.getName(),account.getMoney(),account.getId());
    }

    @Override
    public int delete(int id) {
        return jdbcTemplate.update("DELETE from TABLE account where id=?",id);
    }

    @Override
    public Account findAccountById(int id) {
        List<Account> list = jdbcTemplate.query("select * from account where id = ?", new Object[]{id}, new BeanPropertyRowMapper(Account.class));
        if(list!=null && list.size()>0){
            Account account = list.get(0);
            return account;
        }else{
            return null;
        }
    }

    @Override
    public List<Account> findAccountList() {
        List<Account> list = jdbcTemplate.query("select * from account", new Object[]{}, new BeanPropertyRowMapper(Account.class));
        if(list!=null && list.size()>0){
            return list;
        }else{
            return null;
        }
    }
}

7. service层

public interface IAccountService {


    int add(Account account);

    int update(Account account);

    int delete(int id);

    Account findAccountById(int id);

    List<Account> findAccountList();

}

8. service具体实现类

@Service
public class AccountService implements IAccountService {
    @Autowired
    IAccountDAO accountDAO;
    @Override
    public int add(Account account) {
        return accountDAO.add(account);
    }

    @Override
    public int update(Account account) {
        return accountDAO.update(account);
    }

    @Override
    public int delete(int id) {
        return accountDAO.delete(id);
    }

    @Override
    public Account findAccountById(int id) {
        return accountDAO.findAccountById(id);
    }

    @Override
    public List<Account> findAccountList() {
        return accountDAO.findAccountList();
    }
}

9. 构建一组restful api来展示

@RestController
@RequestMapping("/account") // rest规范： /实体
public class AccountController {

    @Autowired
    IAccountService accountService;

    @RequestMapping(value = "/list",method = RequestMethod.GET)
    public List<Account> getAccounts(){
        return accountService.findAccountList();
    }

    // rest规范，实体名/id
    @RequestMapping(value = "/{id}",method = RequestMethod.GET)
    public  Account getAccountById(@PathVariable("id") int id){
        return accountService.findAccountById(id);
    }

    // rest规范使用Put修改
    @RequestMapping(value = "/{id}",method = RequestMethod.PUT)
    public  String updateAccount(@PathVariable("id")int id , @RequestParam(value = "name",required = true)String name,
                                 @RequestParam(value = "money" ,required = true)double money){
        Account account=new Account();
        account.setMoney(money);
        account.setName(name);
        account.setId(id);
        int t=accountService.update(account);
        if(t==1){
            return account.toString();
        }else {
            return "fail";
        }
    }

    // rest规范使用post新增
    @RequestMapping(value = "",method = RequestMethod.POST)
    public  String postAccount( @RequestParam(value = "name")String name,
                                @RequestParam(value = "money" )double money){
        Account account=new Account();
        account.setMoney(money);
        account.setName(name);
        int t= accountService.add(account);
        if(t==1){
            return account.toString();
        }else {
            return "fail";
        }

    }

}

10. 启动项目，通过postman来测试