在学习HelloWorld之后,我们来尝试构建一个RESTful工程。
- 什么是REST?
首先,REST是Web自身的架构风格。REST也是Web之所以取得成功的技术架构方面因素的总结。REST是世界上最成功的分布式应用架构风格(成功案例:Web,还不够吗?)。它是为 运行在互联网环境 的 分布式 超媒体系统量身定制的。互联网环境与企业内网环境有非常大的差别,最主要的差别是两个方面:
可伸缩性需求无法控制:并发访问量可能会暴涨,也可能会暴跌。
安全性需求无法控制:无法控制客户端发来的请求的格式,很可能会是恶意的请求。
而所谓的“超媒体系统”,即,使用了超文本的系统。可以把“超媒体”理解为超文本+媒体内容。
REST是HTTP/1.1协议等Web规范的设计指导原则,HTTP/1.1协议正是为实现REST风格的架构而设计的。新的Web规范,其设计必须符合REST的要求,否则整个Web的体系架构会因为引入严重矛盾而崩溃。这句话不是危言耸听,做个类比,假如苏州市政府同意在市区著名园林的附近大型土木,建造大量具有后现代风格的摩天大楼,那么不久之后世界闻名的苏州园林美景将不复存在。
上述这些关于“REST是什么”的描述,可以总结为一句话:REST是所有Web应用都应该遵守的架构设计指导原则。当然,REST并不是法律,违反了REST的指导原则,仍然能够实现应用的功能。但是违反了REST的指导原则,会付出很多代价,特别是对于大流量的网站而言。
- REST的关键词
- 资源(Resource)
- 资源的表述(Representation)
- 状态转移(State Transfer)
- 统一接口(Uniform Interface)
- 超文本驱动(Hypertext Driven)
- REST的特征
- 面向资源(Resource Oriented)
- 可寻址(Addressability)
- 连通性(Connectedness)
- 无状态(Statelessness)
- 统一接口(Uniform Interface)
- 超文本驱动(Hypertext Driven)
更多可以参考:理解本真的REST架构风格
-
开始创建RESTful工程
我们依旧使用IDEA作为开发工具,首先依旧是新建一个SpringInitializr项目,这里和前面的HelloWorld程序一样,但是在勾选Dependensencise时需要额外勾上MySQL和MyBaties.
- 创建数据库
DROP TABLE IF EXISTS city
;
CREATE TABLE city
(
id
int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '城市编号',
province_id
int(10) unsigned NOT NULL COMMENT '省份编号',
city_name
varchar(25) DEFAULT NULL COMMENT '城市名称',
description
varchar(25) DEFAULT NULL COMMENT '描述',
PRIMARY KEY (id
)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
+ 创建工程目录如下
![创建工程目录](http://upload-images.jianshu.io/upload_images/3189042-5351ab0a233aa154.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
Controller包里存放控制器:
```java
package org.vzard.springboot.controller;
import jdk.nashorn.internal.ir.RuntimeNode;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.vzard.springboot.domain.City;
import org.vzard.springboot.service.CityService;
import java.util.List;
/**
* Created by V-zar on 2017/7/2.
*/
@RestController
public class CityRestController {
@Autowired
private CityService cityService;
@RequestMapping(value = "/vzard/city/{id}",method = RequestMethod.GET)
public City findOneCity(@PathVariable Long id){
return cityService.findCityById(id);
}
@RequestMapping(value = "/vzard/city",method = RequestMethod.GET)
public List<City> findAllCity(){
return cityService.findAllCity();
}
@RequestMapping(value = "/vzard/city",method = RequestMethod.POST)
public void createCity(@RequestBody City city){
cityService.saveCity(city);
}
@RequestMapping(value = "/vzard/city",method = RequestMethod.PUT)
public void modifyCity(@RequestBody City city){
cityService.updateCity(city);
}
@RequestMapping(value = "/vzard/city/{id}",method = RequestMethod.DELETE)
public void modifyCity(@PathVariable("id") Long id){
cityService.deleteCity(id);
}
}
dao包存放接口类:
package org.vzard.springboot.dao;
import org.apache.ibatis.annotations.Param;
import org.vzard.springboot.domain.City;
import java.util.List;
/**
* 城市DAO接口类
*
* Created by V-zar on 2017/7/2.
*/
public interface CityDao {
/**
* 获取城市信息列表
* @return
*/
List<City> findAllCity();
/**
* 根据id获取城市信息
* @param id
* @return
*/
City findById(@Param("id") Long id);
/**
* 保存城市信息
* @param city
* @return
*/
Long saveCity(City city);
/**
* 更新城市信息
* @param city
* @return
*/
Long updateCity(City city);
/**
* 删除城市信息
* @param id
* @return
*/
Long deleteCity(Long id);
}
domain包存放实体类
package org.vzard.springboot.domain;
/**
* 城市实体类
*
* Created by V-zar on 2017/7/2.
*/
public class City {
/**
* 城市id
*/
private Long id;
/**
* 省份id
*/
private Long provinceId;
/**
* 城市名称
*/
private String cityName;
/**
* 描述
*/
private String description;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Long getProvinceId() {
return provinceId;
}
public void setProvinceId(Long provinceId) {
this.provinceId = provinceId;
}
public String getCityName() {
return cityName;
}
public void setCityName(String cityName) {
this.cityName = cityName;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
service包里存放服务接口及其实现
package org.vzard.springboot.service;
import org.vzard.springboot.domain.City;
import java.util.List;
/**
* 城市业务逻辑接口
*
* Created by V-zar on 2017/7/2.
*/
public interface CityService {
/**
* 获取城市列表
* @return
*/
List<City> findAllCity();
/**
* 根据城市id寻找城市
* @param id
* @return
*/
City findCityById(Long id);
/**
* 保存城市信息
* @param city
* @return
*/
Long saveCity(City city);
/**
* 更新城市信息
* @param city
* @return
*/
Long updateCity(City city);
/**
* 删除城市信息
* @param id
* @return
*/
Long deleteCity(Long id);
}
package org.vzard.springboot.service.impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.vzard.springboot.dao.CityDao;
import org.vzard.springboot.domain.City;
import org.vzard.springboot.service.CityService;
import java.util.List;
/**
* Created by V-zar on 2017/7/2.
*/
@Service
public class CityServiceImpl implements CityService{
@Autowired
private CityDao cityDao;
@Override
public List<City> findAllCity() {
return cityDao.findAllCity();
}
@Override
public City findCityById(Long id) {
return cityDao.findById(id);
}
@Override
public Long saveCity(City city) {
return cityDao.saveCity(city);
}
@Override
public Long updateCity(City city) {
return cityDao.updateCity(city);
}
@Override
public Long deleteCity(Long id) {
return cityDao.deleteCity(id);
}
}
程序入口类
package org.vzard.springboot;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("org.vzard.springboot.dao")
public class SpringbootApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootApplication.class, args);
}
}
数据源&MyBaties&端口配置
#数据源配置
spring.datasource.url=jdbc:mysql://localhost:3306/springbootdb?useUnicode=true&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=5432
spring.datasource.dbcp2.driver-class-name=com.mysql.jdbc.Driver
#Mybatis 配置
mybatis.typeAliasesPackage=org.vzard.springboot.domain
mybatis.mapperLocations=classpath:mapper/*.xml
#配置端口
server.port=${port:8009}
Mybaties映射文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="org.vzard.springboot.dao.CityDao">
<resultMap id="BaseResultMap" type="org.vzard.springboot.domain.City">
<result column="id" property="id" />
<result column="province_id" property="provinceId" />
<result column="city_name" property="cityName" />
<result column="description" property="description" />
</resultMap>
<parameterMap id="City" type="org.vzard.springboot.domain.City"/>
<sql id="Base_Column_List">
id, province_id, city_name, description
</sql>
<select id="findById" resultMap="BaseResultMap" parameterType="java.lang.Long">
select
<include refid="Base_Column_List" />
from city
where id = #{id}
</select>
<select id="findAllCity" resultMap="BaseResultMap" >
select
<include refid="Base_Column_List" />
from city
</select>
<insert id="saveCity" parameterMap="City" useGeneratedKeys="true" keyProperty="id">
insert into
city(id,province_id,city_name,description)
values
(#{id},#{provinceId},#{cityName},#{description})
</insert>
<update id="updateCity" parameterMap="City">
update
city
set
<if test="provinceId!=null">
province_id = #{provinceId},
</if>
<if test="cityName!=null">
city_name = #{cityName},
</if>
<if test="description!=null">
description = #{description}
</if>
where
id = #{id}
</update>
<delete id="deleteCity" parameterType="java.lang.Long">
delete from
city
where
id = #{id}
</delete>
</mapper>
到此工程创建完毕运行程序入口类启动项目:
-
插入记录,URL:http://127.0.0.1:8009/vzard/city
-
更改记录,URL:http://127.0.0.1:8009/vzard/city
-
删除记录,URL:http://127.0.0.1:8009/vzard/city/2
-
查询记录
表单提交的测试工具为Chrome的插件PostMan,很强大
demo