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SpringBoot（四）：SpringBoot整合JdbcTemplate

2018-01-14 16:27 459 查看

个人其实偏向于使用类似于JdbcTemplate这种的框架，返回数据也习惯于接受Map/List形式，而不是转化成对象，一是前后台分离转成json方便，另外是返回数据格式，数据字段可以通过SQL控制，而不是返回整个对象字段数据，或者通过VO方式。当然更多人习惯于采用Bean形式，所以这里也同样使用Bean.

一、数据准备

CREATE TABLE `tb_user` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`username` varchar(50) NOT NULL COMMENT '用户名',
`age` int(11) NOT NULL COMMENT '年龄',
`ctm` datetime NOT NULL COMMENT '创建时间',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('张三', '18', NOW()) ;
INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('李四', '20', NOW()) ;
INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('王五', '19', NOW()) ;

二、引入依赖

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

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

另外web依赖也需要，因为我们采用MVC模式。

<!-- Add typical dependencies for a web application -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

三、数据库配置文件

一如既往，我们采用yaml文件配置，当然properties文件也是一样。

注意点，SpringBoot默认采用tomcat-jdbc连接池，如果需要C3P0，DBCP，Druid等作为连接池，需要加入相关依赖以及配置，这里不作说明，采用默认配置即可。

spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/db_user
username: root
password: root

四、代码

项目结构如下：

实体类User.class

package cn.saytime.bean;

import java.util.Date;

/**
* @ClassName cn.saytime.bean.User
* @Description
* @date 2017-07-04 22:47:28
*/
public class User {

private int id;
private String username;
private int age;
private Date ctm;

public User() {
}

public User(String username, int age) {
this.username = username;
this.age = age;
this.ctm = new Date();
}

// Getter、Setter
}

UserDao.class

package cn.saytime.dao;

import cn.saytime.bean.User;

import java.util.List;

/**
* @ClassName cn.saytime.dao.UserDao
* @Description
* @date 2017-07-04 22:48:45
*/
public interface UserDao {

User getUserById(Integer id);

public List<User> getUserList();

public int add(User user);

public int update(Integer id, User user);

public int delete(Integer id);
}

UserDaoImpl.class

package cn.saytime.dao.impl;

import cn.saytime.bean.User;
import cn.saytime.dao.UserDao;
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.Date;
import java.util.List;

/**
* @ClassName cn.saytime.dao.impl.UserDaoImpl
* @Description
* @date 2017-07-04 22:50:07
*/
@Repository
public class UserDaoImpl implements UserDao {

@Autowired
private JdbcTemplate jdbcTemplate;

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

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

@Override
public int add(User user) {
return jdbcTemplate.update("insert into tb_user(username, age, ctm) values(?, ?, ?)",
user.getUsername(),user.getAge(), new Date());

}

@Override
public int update(Integer id, User user) {
return jdbcTemplate.update("UPDATE tb_user SET username = ? , age = ? WHERE id=?",
user.getUsername(),user.getAge(), id);
}

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

}

UserService.class

package cn.saytime.service;

import cn.saytime.bean.User;
import org.springframework.stereotype.Service;

import java.util.List;

/**
* @ClassName cn.saytime.service.UserService
* @Description
* @date 2017-07-04 22:49:05
*/
public interface UserService {

User getUserById(Integer id);

public List<User> getUserList();

public int add(User user);

public int update(Integer id, User user);

public int delete(Integer id);
}

UserServiceimpl.class

package cn.saytime.service.impl;

import cn.saytime.bean.User;
import cn.saytime.dao.UserDao;
import cn.saytime.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
* @ClassName cn.saytime.service.impl.UserServiceImpl
* @Description
* @date 2017-07-04 22:49:27
*/
@Service
public class UserServiceImpl implements UserService {

@Autowired
private UserDao userDao;

@Override
public User getUserById(Integer id) {
return userDao.getUserById(id);
}

@Override
public List<User> getUserList() {
return userDao.getUserList();
}

@Override
public int add(User user) {
return userDao.add(user);
}

@Override
public int update(Integer id, User user) {
return userDao.update(id, user);
}

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

JsonResult.class 通用json返回类

package cn.saytime.bean;

public class JsonResult {

private String status = null;

private Object result = null;

public JsonResult status(String status) {
this.status = status;
return this;
}

// Getter Setter
}

UserController.class（Restful风格）

package cn.saytime.web;

import cn.saytime.bean.JsonResult;
import cn.saytime.bean.User;
import cn.saytime.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
* @ClassName cn.saytime.web.UserController
* @Description
* @date 2017-07-04 22:46:14
*/
@RestController
public class UserController {

@Autowired
private UserService userService;

/**
* 根据ID查询用户
* @param id
* @return
*/
@RequestMapping(value = "user/{id}", method = RequestMethod.GET)
public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
JsonResult r = new JsonResult();
try {
User user = userService.getUserById(id);
r.setResult(user);
r.setStatus("ok");
} catch (Exception e) {
r.setResult(e.getClass().getName() + ":" + e.getMessage());
r.setStatus("error");
e.printStackTrace();
}
return ResponseEntity.ok(r);
}

/**
* 查询用户列表
* @return
*/
@RequestMapping(value = "users", method = RequestMethod.GET)
public ResponseEntity<JsonResult> getUserList (){
JsonResult r = new JsonResult();
try {
List<User> users = userService.getUserList();
r.setResult(users);
r.setStatus("ok");
} catch (Exception e) {
r.setResult(e.getClass().getName() + ":" + e.getMessage());
r.setStatus("error");
e.printStackTrace();
}
return ResponseEntity.ok(r);
}

/**
* 添加用户
* @param user
* @return
*/
@RequestMapping(value = "user", method = RequestMethod.POST)
public ResponseEntity<JsonResult> add (@RequestBody User user){
JsonResult r = new JsonResult();
try {
int orderId = userService.add(user);
if (orderId < 0) {
r.setResult(orderId);
r.setStatus("fail");
} else {
r.setResult(orderId);
r.setStatus("ok");
}
} catch (Exception e) {
r.setResult(e.getClass().getName() + ":" + e.getMessage());
r.setStatus("error");

e.printStackTrace();
}
return ResponseEntity.ok(r);
}

/**
* 根据id删除用户
* @param id
* @return
*/
@RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
JsonResult r = new JsonResult();
try {
int ret = userService.delete(id);
if (ret < 0) {
r.setResult(ret);
r.setStatus("fail");
} else {
r.setResult(ret);
r.setStatus("ok");
}
} catch (Exception e) {
r.setResult(e.getClass().getName() + ":" + e.getMessage());
r.setStatus("error");

e.printStackTrace();
}
return ResponseEntity.ok(r);
}

/**
* 根据id修改用户信息
* @param user
* @return
*/
@RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
JsonResult r = new JsonResult();
try {
int ret = userService.update(id, user);
if (ret < 0) {
r.setResult(ret);
r.setStatus("fail");
} else {
r.setResult(ret);
r.setStatus("ok");
}
} catch (Exception e) {
r.setResult(e.getClass().getName() + ":" + e.getMessage());
r.setStatus("error");

e.printStackTrace();
}
return ResponseEntity.ok(r);
}

}