SpringBoot整合Swagger2

相信各位在公司写API文档数量应该不少，当然如果你还处在自己一个人开发前后台的年代，当我没说，如今为了前后台更好的对接，还是为了以后交接方便，都有要求写API文档。

手写Api文档的几个痛点：

文档需要更新的时候，需要再次发送一份给前端，也就是文档更新交流不及时。
接口返回结果不明确
不能直接在线测试接口，通常需要使用工具，比如postman
接口文档太多，不好管理

Swagger也就是为了解决这个问题，当然也不能说Swagger就一定是完美的，当然也有缺点，最明显的就是代码移入性比较强。

其他的不多说，想要了解Swagger的，可以去Swagger官网，可以直接使用Swagger editor编写接口文档，当然我们这里讲解的是SpringBoot整合Swagger2，直接生成接口文档的方式。

一、依赖

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.8.0</version>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.8.0</version>
</dependency>

二、Swagger配置类

其实这个配置类，只要了解具体能配置哪些东西就好了，毕竟这个东西配置一次之后就不用再动了。特别要注意的是里面配置了api文件也就是controller包的路径，不然生成的文档扫描不到接口。

@Configuration
@EnableSwagger2
public class SwaggerConfig {
    /**
     * 创建API
     */
    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                // 用来创建该API的基本信息，展示在文档的页面中（自定义展示的信息）
                .apiInfo(apiInfo())
                // 设置哪些接口暴露给Swagger展示
                .select()
                // 扫描所有有注解的api，用这种方式更灵活
                .apis(RequestHandlerSelectors.withMethodAnnotation(ApiOperation.class))
                // 扫描指定包中的swagger注解
                // .apis(RequestHandlerSelectors.basePackage("com.ruoyi.project.tool.swagger"))
                // 扫描所有 .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any()).build();
    }

    /**
     * 添加摘要信息
     */
    private ApiInfo apiInfo() {
        // 用ApiInfoBuilder进行定制
        return new ApiInfoBuilder()
                // 设置标题
                .title("标题：若依管理系统_接口文档")
                // 描述
                .description("描述：用于管理集团旗下公司的人员信息,具体包括XXX,XXX模块...")
                // 作者信息
                .contact(new Contact(Global.getName(), null, null))
                // 版本
                .version("版本号:" + Global.getVersion()).build();
    }
}

用@Configuration注解该类，等价于XML中配置beans；用@Bean标注方法等价于XML中配置bean。

Application.class 加上注解@EnableSwagger2 表示开启Swagger

package cn.saytime;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@SpringBootApplication
@EnableSwagger2
public class SpringbootSwagger2Application {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootSwagger2Application.class, args);
    }
}

三、Restful 接口

package cn.saytime.web;

import cn.saytime.bean.JsonResult;
import cn.saytime.bean.User;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiImplicitParams;
import io.swagger.annotations.ApiOperation;
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.RestController;
import springfox.documentation.annotations.ApiIgnore;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author zh
 * @ClassName cn.saytime.web.UserController
 * @Description
 */
@RestController
public class UserController {

    // 创建线程安全的Map
    static Map<Integer, User> users = Collections.synchronizedMap(new HashMap<Integer, User>());

    /**
     * 根据ID查询用户
     * @param id
     * @return
     */
    @ApiOperation(value="获取用户详细信息", notes="根据url的id来获取用户详细信息")
    @ApiImplicitParam(name = "id", value = "用户ID", required = true, dataType = "Integer", paramType = "path")
    @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            User user = users.get(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
     */
    @ApiOperation(value="获取用户列表", notes="获取用户列表")
    @RequestMapping(value = "users", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserList (){
        JsonResult r = new JsonResult();
        try {
            List<User> userList = new ArrayList<User>(users.values());
            r.setResult(userList);
            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
     */
    @ApiOperation(value="创建用户", notes="根据User对象创建用户")
    @ApiImplicitParam(name = "user", value = "用户详细实体user", required = true, dataType = "User")
    @RequestMapping(value = "user", method = RequestMethod.POST)
    public ResponseEntity<JsonResult> add (@RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            users.put(user.getId(), user);
            r.setResult(user.getId());
            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
     */
    @ApiOperation(value="删除用户", notes="根据url的id来指定删除用户")
    @ApiImplicitParam(name = "id", value = "用户ID", required = true, dataType = "Long", paramType = "path")
    @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            users.remove(id);
            r.setResult(id);
            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
     */
    @ApiOperation(value="更新信息", notes="根据url的id来指定更新用户信息")
    @ApiImplicitParams({
            @ApiImplicitParam(name = "id", value = "用户ID", required = true, dataType = "Long",paramType = "path"),
            @ApiImplicitParam(name = "user", value = "用户实体user", required = true, dataType = "User")
    })
    @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
    public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            User u = users.get(id);
            u.setUsername(user.getUsername());
            u.setAge(user.getAge());
            users.put(id, u);
            r.setResult(u);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

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

    @ApiIgnore//使用该注解忽略这个API
    @RequestMapping(value = "/hi", method = RequestMethod.GET)
    public String  jsonTest() {
        return " hi you!";
    }
}

Json格式输出类 JsonResult.class

package cn.saytime.bean;

public class JsonResult {

    private String status = null;

    private Object result = null;

    // Getter Setter
}

实体User.class

package cn.saytime.bean;

import java.util.Date;

/**
 * @author zh
 * @ClassName cn.saytime.bean.User
 * @Description
 */
public class User {

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

    // Getter Setter
}

四、Swagger2文档

启动SpringBoot项目，访问 http://localhost:8080/swagger-ui.html

运行项目，这个时候可能会报这个错，如下所示

2018-05-28 14:40:56.887 ERROR [main] o.s.boot.SpringApplication - Application startup failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerAdapter' defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Initialization of bean failed; nested exception is java.lang.NoSuchMethodError: com.google.common.collect.FluentIterable.toList()Lcom/google/common/collect/ImmutableList;
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
    at com.qtay.gls.Application.main(Application.java:24)
Caused by: java.lang.NoSuchMethodError: com.google.common.collect.FluentIterable.toList()Lcom/google/common/collect/ImmutableList;
    at springfox.documentation.spring.web.ObjectMapperConfigurer.jackson2Converters(ObjectMapperConfigurer.java:76)
    at springfox.documentation.spring.web.ObjectMapperConfigurer.configureMessageConverters(ObjectMapperConfigurer.java:63)
    at springfox.documentation.spring.web.ObjectMapperConfigurer.postProcessBeforeInitialization(ObjectMapperConfigurer.java:47)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:409)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1620)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    ... 15 common frames omitted

Process finished with exit code 1

在网上搜索了下，加入下面这段代码就OK了！

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.8.0</version>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.8.0</version>
</dependency>
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>25.1-jre</version>
</dependency>

五、Swagger注解

swagger通过注解表明该接口会生成文档，包括接口名、请求方法、参数、返回信息的等等。

@Api：修饰整个类，描述Controller的作用
@ApiOperation：描述一个类的一个方法，或者说一个接口
@ApiParam：单个参数描述
@ApiModel：用对象来接收参数
@ApiProperty：用对象接收参数时，描述对象的一个字段
@ApiResponse：HTTP响应其中1个描述
@ApiResponses：HTTP响应整体描述
@ApiIgnore：使用该注解忽略这个API
@ApiError ：发生错误返回的信息
@ApiImplicitParam：一个请求参数
@ApiImplicitParams：多个请求参数