SpringBoot教程第3篇：JDBCTemplate

本文介绍springboot通过jdbc访问关系型mysql,通过spring的JdbcTemplate去访问。

准备工作

• jdk 1.8
• maven 3.0
• idea
• mysql

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');

创建工程

引入依赖：

在pom文件引入spring-boot-starter-jdbc的依赖：

<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>

配置相关文件

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.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=123456

通过引入这些依赖和配置一些基本信息，springboot就可以访问数据库类。

具体编码

实体类

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

....省略了getter. setter

}

dao层

public interface IAccountDAO {
    int add(Account account);

    int update(Account account);

    int delete(int id);

    Account findAccountById(int id);

    List<Account> findAccountList();
}

具体的实现类：

package com.forezp.dao.impl;

import com.forezp.dao.IAccountDAO;
import com.forezp.entity.Account;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * Created by fangzhipeng on 2017/4/20.
 */
@Repository
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;
        }
    }
}

service层

public interface IAccountService {


    int add(Account account);

    int update(Account account);

    int delete(int id);

    Account findAccountById(int id);

    List<Account> findAccountList();

}

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();
    }
}

构建一组restful api来展示

package com.forezp.web;

import com.forezp.entity.Account;
import com.forezp.service.IAccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * Created by fangzhipeng on 2017/4/20.
 */

@RestController
@RequestMapping("/account")
public class AccountController {

    @Autowired
    IAccountService accountService;

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

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

    @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";
        }
    }

    @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";
        }

    }

}

可以通过postman来测试，具体的我已经全部测试通过，没有任何问题。注意restful构建api的风格。

源码下载：https://github.com/forezp/SpringBootLearning

参考资料

relational-data-access

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