如何在Swagger 1.5.20中为API控制器添加描述？

在Swagger 1.5.20中为API控制器添加描述，可以通过以下步骤实现：

首先，在你的API控制器类上添加Swagger的注解@Api，用于描述该API控制器的信息。例如：

@Api(value = "UserController", description = "Operations pertaining to user management")
@RestController
@RequestMapping("/users")
public class UserController {
    // ...
}

接下来，为每个API方法添加Swagger的注解@ApiOperation，用于描述该API方法的信息。例如：

@ApiOperation(value = "Get a user by ID", response = User.class)
@GetMapping("/{id}")
public ResponseEntity<User> getUserById(@PathVariable Long id) {
    // ...
}

如果需要为API方法的参数添加描述，可以使用Swagger的注解@ApiParam。例如：

@ApiOperation(value = "Create a new user")
@PostMapping("/")
public ResponseEntity<User> createUser(@ApiParam(value = "User object", required = true) @RequestBody User user) {
    // ...
}

如果需要为API方法的返回结果添加描述，可以使用Swagger的注解@ApiResponses和@ApiResponse。例如：

@ApiOperation(value = "Get all users", response = User.class, responseContainer = "List")
@ApiResponses(value = {
        @ApiResponse(code = 200, message = "Successfully retrieved users"),
        @ApiResponse(code = 401, message = "You are not authorized to view the resource"),
        @ApiResponse(code = 403, message = "Accessing the resource you were trying to reach is forbidden"),
        @ApiResponse(code = 404, message = "The resource you were trying to reach is not found")
})
@GetMapping("/")
public ResponseEntity<List<User>> getAllUsers() {
    // ...
}

通过以上步骤，你可以在Swagger 1.5.20中为API控制器添加描述。请注意，Swagger 1.5.20是较旧的版本，建议升级到最新版本以获得更多功能和改进。对于更详细的Swagger注解和配置信息，可以参考Swagger官方文档：Swagger Annotations。