JsonErrorController.java

package io.loli.box.controller;

import org.springframework.beans.factory.annotation.Autowired;
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;

@RestController
public class JsonErrorController implements ErrorController {

    private static final String PATH = "/error";
    @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, true));
    }

    @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);
    }

}

class ErrorJson {

    public Integer status;
    public String error;
    public String message;
    public String timeStamp;
    public 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");
    }

}