上次我們講到前後端開發的時候要以RESTFul風格的API進行開發,這樣減少了前後端交流的口舌,所以我們就來實戰一下,寫一個以RESTFul風格的開發的API
一、前提準備
- IEDA
- Mysql-8.0.18
- Navigator
二、數據庫的建立
首先建立一個叫做RESTFulDemo的數據庫,然後在數據庫裏面建立一個叫做demo_user的表,表的結構如下:
然後導入我事先準備好的數據,這樣就有了數據了
然後建立一個叫做data的表(這個表的名字沒有什麼邏輯,只是爲了此次寫API所寫的demo),並導入我事前準備的數據
三、代碼編寫
- 首先我們需要連接到數據庫,所以加上相關的pom依賴
<!--jdbcTemplate支持-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.1.RELEASE</version>
</dependency>
<!--mysql驅動-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!--添加lombok依賴-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
- 然後再application.properties裏添加數據庫配置
# 添加的數據庫連接
spring.datasource.url=jdbc:mysql://localhost:3306/restfuldemo?useUnicode=true&characterEncoding=utf-8serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=XXXXXX
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.type=com.mysql.cj.jdbc.MysqlConnectionPoolDataSource
其中XXXXXX指的是你的密碼
- 然後寫相關的實體類,與數據庫表相對應
ChartData.java
package com.example.demo.Model;
import lombok.Data;
import lombok.NoArgsConstructor;
@NoArgsConstructor
@Data
public class ChartData {
private String name;//電視臺名稱
private String price;//廣告價格
}
demoUser.java
package com.example.demo.Model;
import lombok.Data;
import lombok.NoArgsConstructor;
@NoArgsConstructor
@Data
public class demoUser {
private String id;//id號
private String name;//姓名
private Integer age;//年齡
private String qq;//qq
private String address;//地址
private String Email;//電子郵件
}
- 然後編寫Dao層接口
IDemoUserDao.java
package com.example.demo.Dao;
import com.example.demo.Model.demoUser;
import java.util.*;
/**
* demoUserDao的接口
*/
public interface IDemoUserDao {
int add(demoUser user);//增加一個demoUser對象
int delete(demoUser user);//刪除一個demoUser對象
int update(demoUser user);//修改
demoUser findOne(String id);//查找到一個
List<demoUser> findAll();//找到所有的demoUser對象
}
由於我此時想測試數據庫是不是能夠連接成功,於是在pom依賴裏面添加了Junit測試starter
<!--添加junit測試依賴-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
然後我們實現IDemoUserDao這個接口並實現其中的add功能
DemoUserDao.java
package com.example.demo.Dao.Impl;
import com.example.demo.Dao.IDemoUserDao;
import com.example.demo.Model.demoUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.stereotype.Repository;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@Repository
public class DemoUserDao implements IDemoUserDao {
@Autowired
private NamedParameterJdbcTemplate jdbcTemplate;
@Override
public int add(demoUser user){
String sql = "insert into demo_user(id,name,age,qq,address,email) "
+ "values(:id,:name,:age,:qq,:address,:email)";
Map<String,Object> param = new HashMap<>();
param.put("id",user.getId());
param.put("name",user.getName());
param.put("age",user.getAge());
param.put("qq",user.getQq());
param.put("address",user.getAddress());
param.put("email",user.getEmail());
return (int) jdbcTemplate.update(sql,param);
}
@Override
public int delete(demoUser user){
return 0;
}
@Override
public int update(demoUser user){
return 0;
}
@Override
public demoUser findOne(String id){
return null;
}
@Override
public List<demoUser> findAll(){
return null;
}
}
然後就要生成我們的測試類,至於idea裏如何生成測試類,還請讀者自行百度。在DemoUser.java文件裏面按住ctrl+shift+t彈出創建測試類的窗口,然後勾選你需要測試的方法。
測試類編寫如下:
package com.example.demo.Dao.Impl;
import com.example.demo.DemoApplication;
import com.example.demo.Model.demoUser;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import static org.junit.jupiter.api.Assertions.*;
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = DemoApplication.class)
class DemoUserDaoTest {
@Autowired
private DemoUserDao userDao;
@Test
void add() {
demoUser user = new demoUser();
user.setId("7988256100");
user.setName("張三娘");
user.setAge(18);
user.setQq("8008208820");
user.setAddress("北京市朝陽區世紀東方城125棟5單元3103室");
user.setEmail("[email protected]");
System.out.println(userDao==null);
userDao.add(user);
System.out.println("插入成功,返回");
}
}
之後運行測試類,發現數據庫有了這條數據,並返回
然後數據庫也有了這條數據
這說明我們的數據庫連接是正常的,接下來我們就要實現其他的代碼了
4.當我們的DAO層寫好之後我們開始寫我們的Service層
部分代碼如下:
package com.example.demo.Service;
import com.example.demo.Dao.Impl.DemoUserDao;
import com.example.demo.Model.demoUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
@Autowired
private DemoUserDao userDao;
public int add(demoUser user){
return userDao.add(user);
}
public int delete(demoUser user){
return userDao.delete(user);
}
public int update(demoUser user){
return userDao.update(user);
}
public demoUser findOne(String id){
return userDao.findOne(id);
}
public List<demoUser> findAll(){
return userDao.findAll();
}
}
- 然後我們要開始寫我們的RESTFul接口的,在寫RESTFul接口之前,我們得寫一個AjaxResponse的Model
AjaxResponse.java
package com.example.demo.Model;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
public class AjaxResponse {
private boolean isOk;
private int code;
private String message;
private Object data;
/**
* 當調用成功不返回數據
* @return
*/
public static AjaxResponse success(){
AjaxResponse resultBean = new AjaxResponse();
resultBean.setOk(true);
resultBean.setCode(200);
resultBean.setMessage("success");
return resultBean;
}
/**
* 當調用成功返回數據
* @param data
* @return
*/
public static AjaxResponse success(Object data){
AjaxResponse resultBean = new AjaxResponse();
resultBean.setOk(true);
resultBean.setCode(200);
resultBean.setMessage("success");
resultBean.setData(data);
return resultBean;
}
/**
* 當調用失敗時
* @return
*/
public static AjaxResponse fail(){
AjaxResponse resultBean = new AjaxResponse();
resultBean.setOk(false);
resultBean.setCode(400);
resultBean.setMessage("failed");
return resultBean;
}
}
爲什麼要寫這樣的一個實體呢,其實寫這個實體是爲了前端調用我們的接口的時候,當成功調用和失敗調用能夠以此返回相應的數據
- 然後編寫相應的contorller類
UserRestController.java
package com.example.demo.Controller;
import com.example.demo.Model.AjaxResponse;
import com.example.demo.Model.demoUser;
import com.example.demo.Service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
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.RestController;
import java.util.List;
import static org.springframework.web.bind.annotation.RequestMethod.*;
@RestController
@RequestMapping("/api")
public class UserRestController {
@Autowired
private UserService userService;
@RequestMapping(value="/users",method = POST,produces = "application/json")
public AjaxResponse addUser(@RequestBody demoUser user){
if(userService.add(user)==1){
return AjaxResponse.success();
}else{
return AjaxResponse.fail();
}
}
@RequestMapping(value="/users/{id}",method = DELETE,produces="application/json")
public AjaxResponse deleteUser(@PathVariable String id){
demoUser user = new demoUser();
user.setId(id);
if(userService.delete(user)==1){
return AjaxResponse.success();
}else{
return AjaxResponse.fail();
}
}
@RequestMapping(value="/users/{id}/{name}",method = PUT,produces="application/json")
public AjaxResponse updateUser(@PathVariable String id,@PathVariable String name,@RequestBody demoUser user){
user.setId(id);
user.setName(name);
if(userService.update(user)==1){
return AjaxResponse.success();
}else{
return AjaxResponse.fail();
}
}
@RequestMapping(value="/users/{id}",method = GET,produces="application/json")
public AjaxResponse getOneUser(@PathVariable String id){
demoUser user;
user = userService.findOne(id);
if(user!=null){
return AjaxResponse.success(user);
}else{
return AjaxResponse.fail();
}
}
@RequestMapping(value="/users",method = GET,produces="application/json")
public AjaxResponse getAllUser(){
List<demoUser> userList;
userList = userService.findAll();
if(userList!=null){
return AjaxResponse.success(userList);
}else{
return AjaxResponse.fail();
}
}
}
- 寫完了controller之後,我們啓動項目並用postman這個工具來做接口測試,至於postman工具如何安裝並使用請讀者自行百度。
當我們在postman發送一個GET請求的時候,請求的路徑爲http://localhost:8080/api/users,這個請求的路徑其實就是獲取所有用戶的信息。
當我們將請求的路徑後面加上用戶的id的時候就能夠獲取到id爲這個的用戶的信息了
三、使用Swagger2構建API發佈文檔
其實寫到前面那裏,我們的RESTFul風格的接口就已經寫好了。現在我們想一下,我們後端寫的接口是要提供給前端使用的,所以前端需要後端接口的API文檔,衆所周知,程序員討厭寫文檔,所以就出現了Swagger2這樣的一個API文檔自動生成的工具,而且能夠實時更新
- 首先添加相關的pom依賴
<!--Swagger2的依賴-->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.6.1</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.6.1</version>
</dependency>
- 然後新建一個叫做config的包,在包裏新建swagger2.java文件
Swagger2.java
package com.example.demo.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Configuration
@EnableSwagger2
public class Swagger2 {
@Bean
public Docket createRestApi(){
return new Docket(DocumentationType.SWAGGER_2)
.apiInfo(apiInfo()).select()
.apis(RequestHandlerSelectors.basePackage("com.example.demo"))
.paths(PathSelectors.regex("/api/.*"))
.build();
}
private ApiInfo apiInfo(){
return new ApiInfoBuilder()
.title("SpringBoot利用swagger構建api文檔")
.description("簡單優雅的RESTFul風格")
.termsOfServiceUrl("http://www.example.com")
.version("1.0")
.build();
}
}
然後運行項目,訪問http://localhost:8080/swagger-ui.html就會顯示下面的樣子
以上就是這次要講的全部內容,源代碼已經上傳至Gitee(碼雲),有需要的小夥伴可以自行下載