Example of replacing Spring Boot "whitelabel" error page with custom error responses (with JSON response body)

CustomErrorController.java

package com.company.project.controllers;

import com.company.project.model.api.ErrorJson;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

/**
 * Based on the helpful answer at http://stackoverflow.com/q/25356781/56285,
 * with error details in response body added.
 * 
 * @author Joni Karppinen
 * @since 20.2.2015
 */
@RestController
public class CustomErrorController implements ErrorController {

    private static final String PATH = "/error";

    @Value("${debug}")
    private boolean debug;

    @Autowired
    private ErrorAttributes errorAttributes;

    @RequestMapping(value = PATH)
    ErrorJson error(HttpServletRequest request, HttpServletResponse response) {
        // Appropriate HTTP response code (e.g. 404 or 500) is automatically set by Spring. 
        // Here we just define response body.
        return new ErrorJson(response.getStatus(), getErrorAttributes(request, debug));
    }

    @Override
    public String getErrorPath() {
        return PATH;
    }

    private Map<String, Object> getErrorAttributes(HttpServletRequest request, boolean includeStackTrace) {
        RequestAttributes requestAttributes = new ServletRequestAttributes(request);
        return errorAttributes.getErrorAttributes(requestAttributes, includeStackTrace);
    }

}

I am getting this error :

2017-02-06 13:15:31.805 WARN 12584 --- [ost-startStop-1] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'mappingError' method
org.springframework.http.ResponseEntity<java.lang.String> com.cisco.eloqua.app.MappingError.error(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
to {[/error]}: There is already 'customErrorController' bean method
org.springframework.http.ResponseEntity<java.lang.String> com.cisco.eloqua.app.CustomErrorController.error(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) mapped.
2017-02-06 13:15:31.981 INFO 12584 --- [ost-startStop-1] utoConfigurationReportLoggingInitializer :

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-02-06 13:15:32.002 ERROR 12584 --- [ost-startStop-1] o.s.boot.SpringApplication : Application startup failed

I modified little bit:

@RequestMapping(value = PATH)
ResponseEntity error(HttpServletRequest request, HttpServletResponse response) {
HttpHeaders responseHeaders = new HttpHeaders();
HttpStatus httpStatus = org.springframework.http.HttpStatus.valueOf(response.getStatus());
return new ResponseEntity("Cannot Process Your Request Right Now! Please Contact the Administrator for more detail.", responseHeaders,httpStatus);
}

package io.apptrade.spring.controller;

import io.apptrade.spring.model.ErrorJson;
import lombok.extern.java.Log;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

@log
@RestController
@propertysource("classpath:application.properties") //custom-error-controller.debug place in file and set true/false
@configuration
public class CustomErrorController implements ErrorController{

private static final String PATH = "/error";

@Value("${custom-error-controller.debug}")
private boolean debug;

@Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
    return new PropertySourcesPlaceholderConfigurer();
}

@Autowired
private ErrorAttributes errorAttributes;

@RequestMapping(value = PATH)
ResponseEntity<ErrorJson> error(HttpServletRequest request, HttpServletResponse response){
     return ResponseEntity.status(response.getStatus())
         .body(
             new ErrorJson(response.getStatus(), getErrorAttributes(request, debug)
         )
     );
}

@Override
public String getErrorPath(){
    return PATH;
}

private Map<String, Object> getErrorAttributes(HttpServletRequest request, boolean includeStackTrace) {
    RequestAttributes requestAttributes = new ServletRequestAttributes(request);
    return errorAttributes.getErrorAttributes(requestAttributes, includeStackTrace);
}

}

package io.apptrade.spring.model;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonIgnore;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.springframework.stereotype.Component;

import java.util.Map;

@JsonAutoDetect(getterVisibility = JsonAutoDetect.Visibility.PUBLIC_ONLY)
@Getter(AccessLevel.PUBLIC)
@Setter(AccessLevel.PROTECTED)
@NoArgsConstructor
@component
public class ErrorJson{

private Integer status;
private String error;

@JsonIgnore
private String message;
private String timeStamp;
private String trace;

public ErrorJson(int status, Map<String, Object> errorAttributes) {
    this.status = status;
    this.error = (String) errorAttributes.get("error");
    this.message = (String) errorAttributes.get("message");
    this.timeStamp = errorAttributes.get("timestamp").toString();
    this.trace = (String) errorAttributes.get("trace");
}

}
THIS Works!! and has been tested. Produces JSON

Thank you very much!

Hi
i get this error:

java: cannot access org.springframework.web.reactive.function.server.ServerRequest
class file for org.springframework.web.reactive.function.server.ServerRequest not found

Slightly change the class to use webrequest

`public class CustomErrorController implements ErrorController {

private static final String PATH = "/error";

@Value("${custom-error-controller.debug}")
private boolean debug;

@Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
    return new PropertySourcesPlaceholderConfigurer();
}

@Autowired
private ErrorAttributes errorAttributes;

@RequestMapping(value = PATH)
ResponseEntity<ErrorJson> error(WebRequest webRequest, HttpServletResponse response){
    return ResponseEntity.status(response.getStatus())
            .body(
                    new ErrorJson(response.getStatus(), getErrorAttributes(webRequest, debug)
                    )
            );
}

@Override
public String getErrorPath(){
    return PATH;
}

private Map<String, Object> getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) {
    return errorAttributes.getErrorAttributes(webRequest, includeStackTrace);
}

}`

here is my implementation:
File: application.properties
server.error.whitelabel.enabled=false
File: OverrideErrorWhitePage.java

@Controller
public class OverrideErrorWhitePage implements ErrorController {
  private static final String ERROR_PATH = "/error";

  @ResponseBody
  @ResponseStatus(HttpStatus.NOT_FOUND)
  @RequestMapping(value = ERROR_PATH, produces = MediaType.APPLICATION_JSON_VALUE)
  public EcatalogGenericResponse handleError() {
    return ResponseBodyBuilder.notFoundHandler();
  }

  @Override
  public String getErrorPath() {
    return ERROR_PATH;
  }
}

File:App.java

@SpringBootApplication
public class Application {

  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

File: EcatalogGenericResponse.java

public class EcatalogGenericResponse<T> {
  private String responseCode;
  private String responseMessage;
  private T data;
}

I want to know how to send error response to custom page in Latest Spring Boot. I tried below mention code but its converts message to JSON format.

@RestController
public class MyCustomErrorHandlerController implements ErrorController {

private static final String PATH = "/error";

@Value("${debug}")
private boolean debug;

@Autowired
private ErrorAttributes errorAttributes;

@RequestMapping(value = PATH)
ErrorJson error(HttpServletRequest request, HttpServletResponse response) {
    // Appropriate HTTP response code (e.g. 404 or 500) is automatically set by Spring. 
    // Here we just define response body.
	//return new Error(response.getStatus(), getErrorAttributes(request, debug));
    return new ErrorJson(response.getStatus(), getErrorAttributes(request, debug));
}

@Override
public String getErrorPath() {
    return PATH;
}

private Map<String, Object> getErrorAttributes(HttpServletRequest request, boolean includeStackTrace) {
	WebRequest webRequest = new ServletWebRequest(request);
    return errorAttributes.getErrorAttributes(webRequest, includeStackTrace);
}

}

I am getting HTTP ERROR 406 code. Anyone has this problem before, at server side everything looks good, but client rejecting the request. I am thinking it is because, browser expecting html and from the server we are trying to send json response?