others-how to solve Whitelabel Error Page with spring 2.x and gradle 6.x ?

Problem

When we naviate to http://localhost:8080 of a spring boot application, we got this:

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

There was an unexpected error (type=Not Found, status=404).

The core error is : Whitelabel Error Page

Why do this error happen?

Environment

  • Spring boot 2.x
  • Gradle 6.x

Reason

Your app has an internal error, and spring boot does not know how to handle it , it only show ‘Whitelabel Error Page’ to indicate that there is an error in your app, you should try to find it.

Solution

Step #1: Add an ErrorController to spring boot app

ErrorController is a :

Marker interface used to identify a @Controller that should be used to render errors.

Add a CustomErrorHandler to your app like this:

package org.example;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.boot.web.servlet.error.ErrorController;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.WebRequest;

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

@RestController
public class CustomErrorController implements ErrorController {
    private static final String PATH = "error";

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

    @Autowired
    private ErrorAttributes errorAttributes;

    @RequestMapping(PATH)
    @ResponseBody
    public CustomHttpErrorResponse error(WebRequest request, HttpServletResponse response) {
        return new CustomHttpErrorResponse(response.getStatus(), getErrorAttributes(request));
    }

    public void setErrorAttributes(ErrorAttributes errorAttributes) {
        this.errorAttributes = errorAttributes;
    }

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

    private Map<String, Object> getErrorAttributes(WebRequest request) {
        Map<String, Object> map = new HashMap<>();
        map.putAll(this.errorAttributes.getErrorAttributes(request, this.debug));
        return map;
    }
}

Step #2: Add custom error response

package org.example;

import java.util.Map;

public class CustomHttpErrorResponse {
    private Integer status;
    private String path;
    private String errorMessage;
    private String timeStamp;
    private String trace;

    public CustomHttpErrorResponse(int status, Map<String, Object> errorAttributes) {
        this.setStatus(status);
        this.setPath((String) errorAttributes.get("path"));
        this.setErrorMessage((String) errorAttributes.get("message"));
        this.setTimeStamp(errorAttributes.get("timestamp").toString());
        this.setTrace((String) errorAttributes.get("trace"));
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public String getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(String errorMessage) {
        this.errorMessage = errorMessage;
    }

    public String getTimeStamp() {
        return timeStamp;
    }

    public void setTimeStamp(String timeStamp) {
        this.timeStamp = timeStamp;
    }

    public String getTrace() {
        return trace;
    }

    public void setTrace(String trace) {
        this.trace = trace;
    }
}

Step #3: Add error handling properties in application.properties

Add these properties to your application.properties as follows:

server.error.whitelabel.enabled=false
debug=true

The server.error.whitelabel.enabled is defined as follows:

Set server.error.whitelabel.enabled=false to switch the default error page off which will restore the default of the servlet container that you are using. Note that Spring Boot will still attempt to resolve the error view so you’d probably add you own error page rather than disabling it completely.

Step #4: Test again

Now when we run the app again, we get this detailed error message in the browser:

{"status":400,"path":"/graphql","errorMessage":"Required String parameter 'query' is not present","timeStamp":"Fri Jan 29 14:56:38 CST 2021","trace":"org.springframework.web.bind.MissingServletRequestParameterException: Required String parameter 'query' is not present\n\tat org.springframework.web.method.annotation.RequestParamMethodArgumentResolver.handleMissingValue(RequestParamMethodArgumentResolver.java:204)\n\tat org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver.resolveArgument(AbstractNamedValueMethodArgumentResolver.java:114)\n\tat org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:167)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\n\tat org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:626)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:733)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589)\n\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)\n\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\n\tat java.lang.Thread.run(Thread.java:745)\n"}

It works!

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