导入swagger依赖（在maven项目pom.xml中添加以下依赖）
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.9.2</version>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.9.2</version>
</dependency>
在主程序中添加@EnableSwagger2
@SpringBootApplication
@EnableSwagger2
public class MainApplication {
	public static void main(String[] args) {
		SpringApplication.run(MainApplication.class, args);
	}
}

在需要api的类上面添加注解
@RestController
@Api(tags = "UserinfoCtrl", description = "用户信息相关")  
public class testswaggercontroller {
	@RequestMapping("/testswagger")
	@ApiOperation(value = "获取用户信息", httpMethod = "GET", notes = "显示用户信息")  
	public Map<String, Object> fun() {
		Map<String , Object> result=new HashMap<String,Object>();
		result.put("test", "test");
		Demo demo=new Demo("junye", "1");
		result.put("Demo", demo);
		System.out.println("chenggong");
		return result;
	}
}
测试是否生成了api：浏览器访问：localhost:8080/swagger-ui.html#