自定义异常，异常Advice，restTemplate异常处理

http://blog.sizovs.net/spring-rest-exception-handler/

1.自定义异常

public class MyException extends RuntimeException{

    public MyException(String message) {
        super(message);
    }
}


@ResponseStatus(HttpStatus.NOT_FOUND)
public class MyNotFoundException extends MyException {
    public MyNotFoundException(String content,Object keyword) {
        super(String.join(": ","找不到"+content+"，关键字", keyword.toString()));
    }
}

2.异常处理

@ControllerAdvice
public class ExceptionHandlerAdvice {
    /*******************************************
     * 自定义异常处理
     *************************************************/
    @ExceptionHandler(MyException.class)
    ResponseEntity<MyExceptionRepresentation> myExceptionHandle(MyException e) {
        HttpStatus responseStatus = resolveAnnotatedResponseStatus(e);
        MyExceptionRepresentationbody = new MyExceptionRepresentation(e, responseStatus);
        return new ResponseEntity<>(body, responseStatus);
    }


    /*******************************************
     * 其他已知异常，消息定制化处理
     ************************************************/
    @ExceptionHandler(MethodArgumentTypeMismatchException.class)
    ResponseEntity<MyExceptionRepresentation> methodArgumentTypeMismatchException(MethodArgumentTypeMismatchException e) {
        String message = String.join("参数的错误输入: ", e.getName(), e.getValue().toString());
        MyExceptionRepresentation body = new MyExceptionRepresentation(e,message, HttpStatus.BAD_REQUEST);
        return new ResponseEntity<>(body, HttpStatus.BAD_REQUEST);
    }

    ///解析状态码
    public static HttpStatus resolveAnnotatedResponseStatus(Exception exception) {
        ResponseStatus annotation = findMergedAnnotation(exception.getClass(), ResponseStatus.class);
        if (annotation != null) {
            return annotation.value();
        }
        return HttpStatus.INTERNAL_SERVER_ERROR;
    }
}

@Data
class MyExceptionRepresentation {
    private boolean myException= true;
    private Date timestamp;
    private int status;
    private String error;
    private String exception;
    private String message;
    private String path;

    public MyExceptionRepresentation(Exception e, HttpStatus responseStatus) {
        this(e, e.getLocalizedMessage(),responseStatus);
    }

    public MyExceptionRepresentation(Exception e, String message, HttpStatus responseStatus) {
        this.timestamp = new Date();
        this.status = responseStatus.value();
        this.error = responseStatus.getReasonPhrase();
        this.exception = e.getClass().getName();
        this.message = message;
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        this.path = request.getServletPath();
    }
}

3.RestTempldate处理异常

public class MyErrorHandler implements ResponseErrorHandler {  
    @Override  
    public void handleError(ClientHttpResponse response) throws IOException {  
       String e = CharStreams.toString(new InputStreamReader(response.getBody()));  
        JSONObject exception = JSONObject.fromObject(e);  
        boolean myException = (boolean) exception.getOrDefault("myException", false);  
        if (myException) {
            throw new RuntimeException((String) exception.get("message"));  
        } else {  
            throw new RuntimeException(exception.toString()); 
        }  
    }  
}  


public class RestTemplateTest {

    RestTemplate restTemplate;

    @Before
    public void setUp(){
        restTemplate = new RestTemplate();
        restTemplate.setErrorHandler(new MyErrorHandler());
    }

    @Test
    public void testSuccessAndMyException() {
//        String url = "http://localhost:9124/course/list/试用期";
        String url = "http://localhost:9124/course/list/试用";
        try {
            Arrays.stream(restTemplate.getForObject(url, Course[].class))
                .map(Course::getName)
                .forEach(System.out::println);
        } catch (MyException e) {
            System.out.println(e.getMessage());
            System.out.println(e.getExceptionName());
        }
    }
}