Spring REST Error Handling Example
By：Roy.LiuLast updated：2019-08-11
In this article, we will show you error handling in Spring Boot REST application.
Technologies used :
- Spring Boot 2.1.2.RELEASE
- Spring 5.1.4.RELEASE
- Maven 3
- Java 8
1. /error
1.1 By default, Spring Boot provides a BasicErrorController controller for /error mapping that handles all errors, and getErrorAttributes to produce a JSON response with details of the error, the HTTP status, and the exception message.
{
"timestamp":"2019-02-27T04:03:52.398+0000",
"status":500,
"error":"Internal Server Error",
"message":"...",
"path":"/path"
BasicErrorController.java
package org.springframework.boot.autoconfigure.web.servlet.error;
//...
@Controller
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {
//...
@RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
Map<String, Object> body = getErrorAttributes(request,
isIncludeStackTrace(request, MediaType.ALL));
HttpStatus status = getStatus(request);
return new ResponseEntity<>(body, status);
In the IDE, puts a breakpoint in this method, you will understand how Spring Boot generates the default JSON error response.
2. Custom Exception
In Spring Boot, we can use @ControllerAdvice to handle custom exceptions.
2.1 A custom exception.
BookNotFoundException.java
package com.mkyong.error;
public class BookNotFoundException extends RuntimeException {
public BookNotFoundException(Long id) {
super("Book id not found : " + id);
A controller, if a book id is not found, throws the above BookNotFoundException
BookController.java
package com.mkyong;
//...
@RestController
public class BookController {
@Autowired
private BookRepository repository;
// Find
@GetMapping("/books/{id}")
Book findOne(@PathVariable Long id) {
return repository.findById(id)
.orElseThrow(() -> new BookNotFoundException(id));
//...
By default, Spring Boot generates the following JSON error response, http 500 error.
Terminal
curl localhost:8080/books/5 "timestamp":"2019-02-27T04:03:52.398+0000", "status":500, "error":"Internal Server Error", "message":"Book id not found : 5", "path":"/books/5"
2.2 If a book id not found, it should return a 404 error instead of 500, we can override the status code like this :
CustomGlobalExceptionHandler.java
package com.mkyong.error;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
import javax.servlet.http.HttpServletResponse;
import javax.validation.ConstraintViolationException;
import java.io.IOException;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
@ControllerAdvice
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
// Let Spring BasicErrorController handle the exception, we just override the status code
@ExceptionHandler(BookNotFoundException.class)
public void springHandleNotFound(HttpServletResponse response) throws IOException {
response.sendError(HttpStatus.NOT_FOUND.value());
//...
2.3 It returns a 404 now.
Terminal
curl localhost:8080/books/5 "timestamp":"2019-02-27T04:21:17.740+0000", "status":404, "error":"Not Found", "message":"Book id not found : 5", "path":"/books/5"
2.4 Furthermore, we can customize the entire JSON error response :
CustomErrorResponse.java
package com.mkyong.error;
import com.fasterxml.jackson.annotation.JsonFormat;
import java.time.LocalDateTime;
public class CustomErrorResponse {
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss")
private LocalDateTime timestamp;
private int status;
private String error;
//...getters setters
CustomGlobalExceptionHandler.java
package com.mkyong.error;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
import java.time.LocalDateTime;
@ControllerAdvice
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
@ExceptionHandler(BookNotFoundException.class)
public ResponseEntity<CustomErrorResponse> customHandleNotFound(Exception ex, WebRequest request) {
CustomErrorResponse errors = new CustomErrorResponse();
errors.setTimestamp(LocalDateTime.now());
errors.setError(ex.getMessage());
errors.setStatus(HttpStatus.NOT_FOUND.value());
return new ResponseEntity<>(errors, HttpStatus.NOT_FOUND);
//...
Terminal
curl localhost:8080/books/5 "timestamp":"2019-02-27 12:40:45", "status":404, "error":"Book id not found : 5"
3. JSR 303 Validation error
3.1 For Spring @valid validation errors, it will throw handleMethodArgumentNotValid
CustomGlobalExceptionHandler.java
package com.mkyong.error;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
import javax.servlet.http.HttpServletResponse;
import javax.validation.ConstraintViolationException;
import java.io.IOException;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
@ControllerAdvice
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
//...
// @Validate For Validating Path Variables and Request Parameters
@ExceptionHandler(ConstraintViolationException.class)
public void constraintViolationException(HttpServletResponse response) throws IOException {
response.sendError(HttpStatus.BAD_REQUEST.value());
// error handle for @Valid
@Override
protected ResponseEntity<Object>
handleMethodArgumentNotValid(MethodArgumentNotValidException ex,
HttpHeaders headers,
HttpStatus status, WebRequest request) {
Map<String, Object> body = new LinkedHashMap<>();
body.put("timestamp", new Date());
body.put("status", status.value());
//Get all fields errors
List<String> errors = ex.getBindingResult()
.getFieldErrors()
.stream()
.map(x -> x.getDefaultMessage())
.collect(Collectors.toList());
body.put("errors", errors);
return new ResponseEntity<>(body, headers, status);
4. ResponseEntityExceptionHandler
4.1 If we are not sure, what exception was thrown by the Spring Boot, puts a breakpoint in this method for debugging.
ResponseEntityExceptionHandler.java
package org.springframework.web.servlet.mvc.method.annotation;
//...
public abstract class ResponseEntityExceptionHandler {
@ExceptionHandler({
HttpRequestMethodNotSupportedException.class,
HttpMediaTypeNotSupportedException.class,
HttpMediaTypeNotAcceptableException.class,
MissingPathVariableException.class,
MissingServletRequestParameterException.class,
ServletRequestBindingException.class,
ConversionNotSupportedException.class,
TypeMismatchException.class,
HttpMessageNotReadableException.class,
HttpMessageNotWritableException.class,
MethodArgumentNotValidException.class,
MissingServletRequestPartException.class,
BindException.class,
NoHandlerFoundException.class,
AsyncRequestTimeoutException.class
})
@Nullable
public final ResponseEntity<Object> handleException(Exception ex, WebRequest request) throws Exception {
HttpHeaders headers = new HttpHeaders();
if (ex instanceof HttpRequestMethodNotSupportedException) {
HttpStatus status = HttpStatus.METHOD_NOT_ALLOWED;
return handleHttpRequestMethodNotSupported((HttpRequestMethodNotSupportedException) ex, headers, status, request);
else if (ex instanceof HttpMediaTypeNotSupportedException) {
HttpStatus status = HttpStatus.UNSUPPORTED_MEDIA_TYPE;
return handleHttpMediaTypeNotSupported((HttpMediaTypeNotSupportedException) ex, headers, status, request);
//...
//...
5. DefaultErrorAttributes
5.1 To override the default JSON error response for all exceptions, create a bean and extends DefaultErrorAttributes
CustomErrorAttributes.java
package com.mkyong.error;
import org.springframework.boot.web.servlet.error.DefaultErrorAttributes;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.WebRequest;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;
@Component
public class CustomErrorAttributes extends DefaultErrorAttributes {
private static final DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
@Override
public Map<String, Object> getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) {
// Let Spring handle the error first, we will modify later :)
Map<String, Object> errorAttributes = super.getErrorAttributes(webRequest, includeStackTrace);
// format & update timestamp
Object timestamp = errorAttributes.get("timestamp");
if (timestamp == null) {
errorAttributes.put("timestamp", dateFormat.format(new Date()));
} else {
errorAttributes.put("timestamp", dateFormat.format((Date) timestamp));
// insert a new key
errorAttributes.put("version", "1.2");
return errorAttributes;
Now, the date time is formatted and a new field – version is added to the JSON error response.
curl localhost:8080/books/5 "timestamp":"2019/02/27 13:34:24", "status":404, "error":"Not Found", "message":"Book id not found : 5", "path":"/books/5", "version":"1.2" curl localhost:8080/abc "timestamp":"2019/02/27 13:35:10", "status":404, "error":"Not Found", "message":"No message available", "path":"/abc", "version":"1.2"
Done.
From：一号门
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