背景
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。
另外送上一波关于Swagger的google hack:intitle:"Swagger UI - " "Show/Hide",可用于参考别人的restful接口,切不可蓄意破坏!
依赖
<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>
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。
package cn.saytime;
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;
/**
 * @author zh
 * @ClassName cn.saytime.Swgger2
 * @Description
 * @date 2017-07-10 22:12:31
 */
@Configuration
public class Swagger2 {
    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .select()
                .apis(RequestHandlerSelectors.basePackage("cn.saytime.web"))
                .paths(PathSelectors.any())
                .build();
    }
    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("springboot利用swagger构建api文档")
                .description("简单优雅的restfun风格,http://blog.csdn.net/saytime")
                .termsOfServiceUrl("http://blog.csdn.net/saytime")
                .version("1.0")
                .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);
    }
}
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
}
项目结构:

Swagger2文档
具体里面的内容以及接口测试,应该一看就懂了。这里就不一一截图了。
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