Spring Cloud Spring Boot mybatis distributed microservice cloud architecture (12) returns JSON format

In the above example, @ControllerAdvicedifferent Exceptions are mapped to different error handling pages by uniformly defining them. When we want to implement a RESTful API, the error returned is JSON formatted data, not HTML pages, which we can easily support at this time.

Essentially, just add it @ExceptionHandlerlater to @ResponseBodyconvert the content of the handler function return to JSON format.

The following uses a specific example to implement the exception handling that returns JSON format.

• Create a unified JSON return object, code: message type, message: message content, url: requested url, data: data returned by the request

  public class ErrorInfo<T> {
  
      public static final Integer OK = 0;
      public static final Integer ERROR = 100;
  
      private Integer code;
      private String message;
      private String url;
      private T data;
  
      // 省略getter和setter
  
  }

   

• Create a custom exception to experimentally capture the exception and return json

  public class MyException extends Exception {
  
      public MyException(String message) {
          super(message);
      }
      
  }

   

• ControllerAdd json mapping in , throw MyExceptionexception

  @Controller
  public class HelloController {
  
      @RequestMapping("/json")
      public String json() throws MyException {
          throw new MyException("发生错误2");
      }
  
  }

   

• Create corresponding handlers for MyExceptionexceptions

  @ControllerAdvice
  public class GlobalExceptionHandler {
  
      @ExceptionHandler(value = MyException.class)
      @ResponseBody
      public ErrorInfo<String> jsonErrorHandler(HttpServletRequest req, MyException e) throws Exception {
          ErrorInfo<String> r = new ErrorInfo<>();
          r.setMessage(e.getMessage());
          r.setCode(ErrorInfo.ERROR);
          r.setData("Some Data");
          r.setUrl(req.getRequestURL().toString());
          return r;
      }
  
  }
  

   

• Start the application and visit: http://localhost:8080/json, you can get the following return content :

• {
      code: 100，
      data: "Some Data"，
      message: "发生错误2"，
      url: "http://localhost:8080/json"
  }

  So far, the creation of unified exception handling in Spring Boot has been completed. The actual implementation still relies on Spring MVC annotations. For more in-depth use, please refer to the Spring MVC documentation.

• source code