I want to write some message to response if exceptions occur in controller ,To do this I need response object .Can I access current response/request object staticly or I have to pass this object to exception too.like in jsf (FacesContext.getCurrentInstance().getExternalContext().getResponse());
List<View_Probes> getAllProbes(HttpServletResponse response) throws ResourceNotFoundException{
try {
List<Probe> probes= inseptraPersistenceService.listAllProbes();
List<View_Probes> result= mapper.mapAll(probes, View_Probes.class);
return result;
} catch (Exception e) {
throw new ResourceNotFoundException(e);
}
}
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
public ResourceNotFoundException() {
}
public ResourceNotFoundException(Throwable e) {
super(e);
}
}
Related
Using ASP.NET WebApi 2,
Why can't I catch HttpRequestValidationException in my Global ExceptionHandler or Global ExceptionLogger?
Error is: [HttpRequestValidationException (0x80004005): A potentially dangerous Request.QueryString value was detected from the client...]
Using Application_Error works fine, HttpRequestValidationException can be caught fine.
WebApiConfig.cs
public static void Register(HttpConfiguration config)
{
//...stuffs
//Global exception handler
config.Services.Replace(typeof(IExceptionHandler), new GlobalExceptionHandler());
//add global error logger
config.Services.Add(typeof(IExceptionLogger), new GlobalExceptionLogger());
}
public class GlobalExceptionLogger : ExceptionLogger
{
public override void Log(ExceptionLoggerContext context)
{
//This does not handle HttpRequestValidationException
Exception exception = context.ExceptionContext.Exception;
//.....
}
}
public class GlobalExceptionHandler : ExceptionHandler
{
public override void Handle(ExceptionHandlerContext context)
{
//This does not handle HttpRequestValidationException either ...
var result = new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("An unexpected error occured. Please notify your administrator"),
ReasonPhrase = "Unexpected Error"
};
context.Result = new UnhandledExceptionResult(context.Request, result);
}
public class UnhandledExceptionResult : IHttpActionResult
{
private HttpRequestMessage _request;
private HttpResponseMessage _httpResponseMessage;
public UnhandledExceptionResult(HttpRequestMessage request, HttpResponseMessage httpResponseMessage)
{
_request = request;
_httpResponseMessage = httpResponseMessage;
}
public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
{
return Task.FromResult(_httpResponseMessage);
}
}
}
I've been trying to fetch exception text from backend (ASP.NET Core) in Angular app.
I've seen examples where the controller action's return type is JsonResult or ActionResult.
In this case we can do the following:
[HttpGet]
public ActionResult GetSomething()
{
...
}
catch (Exception ex)
{
return Json(new { error = $"{ex.GetType().FullName}: '{ex.Message}'" }, JsonRequestBehavior.AllowGet);
}
}
All controller actions I have return DTOs, e.g.
public async Task<List<OrderDto>> GetMany(long clientId)
{
....
Since I'm returning DTO - I can't seem to return Json, so the approach above doesn't work.
I wonder if there's a way to pass exception description other than via Json(...).
Does anyone have an idea of how to handle this?
You can create a middleware:
public class ExceptionHandleMiddleware
{
private readonly RequestDelegate next;
public ExceptionHandleMiddleware(RequestDelegate next)
{
this.next = next ?? throw new ArgumentNullException(nameof(next));
}
public async Task Invoke(HttpContext context)
{
try
{
await next(context);
}
catch (Exception ex)
{
context.Response.Clear();
context.Response.ContentType = #"application/json";
await context.Response.WriteAsync(JsonConvert.SerializeObject(new { error = $"{ex.GetType().FullName}: '{ex.Message}'"}));
}
}
}
And then add it to application Builder in Configure method:
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
....
app.UseMiddleware<ExceptionHandleMiddleware>();
}
Pay attention that with this middleware you shouldn't catch your exception on Controller level.
I have the following controller logic. However, if I navigate to a non-existing page (e.g. /random-page), I end up with a TemplateInputException. How can I catch this and go to the 404 page?
#RequestMapping(value = { "{path:(?!resources|error).*$}", "{path:(?!resources|error).*$}/**" }, headers = "Accept=text/html")
public String index(final HttpServletRequest request) {
try {
String path = (String) request.getAttribute(
HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
return path.split("/")[1];
} catch (Exception e) {
log.error("Failed to render the page. {}",e);
return "error/general";
}
}
Thymeleaf seems to be ignoring the ExceptionHandler:
#ExceptionHandler(Exception.class)
public ModelAndView handleAllException(Exception ex) {
ModelAndView model = new ModelAndView("error/generic_error");
model.addObject("errMsg", "this is Exception.class");
return model;
}
My workaround this problem for spring-boot (exception is view with message param):
#Controller
public class ErrorController implements org.springframework.boot.autoconfigure.web.ErrorController {
private static final String ERROR_PATH = "/error";
#Autowired
private ErrorAttributes errorAttributes;
#Override
public String getErrorPath() {
return ERROR_PATH;
}
#RequestMapping(ERROR_PATH)
public String error(HttpServletRequest request, Model model) {
Map<String, Object> errorMap = errorAttributes.getErrorAttributes(new ServletRequestAttributes(request), false);
String exception = (String) errorMap.get("exception");
if (exception != null && exception.contains("TemplateInputException")) {
errorMap.put("message", "Неверный запрос");
}
model.addAllAttributes(errorMap);
return "exception";
}
}
i'm currently have a look a springboot undertow and it's not really clear (for me) how to dispatch an incoming http request to a worker thread for blocking operation handling.
Looking at the class UndertowEmbeddedServletContainer.class, it look like there is no way to have this behaviour since the only HttpHandler is a ServletHandler, that allow #Controller configurations
private Undertow createUndertowServer() {
try {
HttpHandler servletHandler = this.manager.start();
this.builder.setHandler(getContextHandler(servletHandler));
return this.builder.build();
}
catch (ServletException ex) {
throw new EmbeddedServletContainerException(
"Unable to start embdedded Undertow", ex);
}
}
private HttpHandler getContextHandler(HttpHandler servletHandler) {
if (StringUtils.isEmpty(this.contextPath)) {
return servletHandler;
}
return Handlers.path().addPrefixPath(this.contextPath, servletHandler);
}
By default, in undertow all requests are handled by IO-Thread for non blocking operations.
Does this mean that every #Controller executions will be processed by a non blocking thread ? or is there a solution to chose from IO-THREAD or WORKER-THREAD ?
I try to write a workaround, but this code is pretty uggly, and maybe someone has a better solution:
BlockingHandler.class
#Target({ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
#Documented
public #interface BlockingHandler {
String contextPath() default "/";
}
UndertowInitializer.class
public class UndertowInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
#Override
public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
configurableApplicationContext.addBeanFactoryPostProcessor(new UndertowHandlerPostProcessor());
}
}
UndertowHandlerPostProcessor.class
public class UndertowHandlerPostProcessor implements BeanDefinitionRegistryPostProcessor {
#Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException {
ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(false);
scanner.addIncludeFilter(new AnnotationTypeFilter(BlockingHandler.class));
for (BeanDefinition beanDefinition : scanner.findCandidateComponents("org.me.lah")){
try{
Class clazz = Class.forName(beanDefinition.getBeanClassName());
beanDefinitionRegistry.registerBeanDefinition(clazz.getSimpleName(), beanDefinition);
} catch (ClassNotFoundException e) {
throw new BeanCreationException(format("Unable to create bean %s", beanDefinition.getBeanClassName()), e);
}
}
}
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {
//no need to post process defined bean
}
}
override UndertowEmbeddedServletContainerFactory.class
public class UndertowEmbeddedServletContainerFactory extends AbstractEmbeddedServletContainerFactory implements ResourceLoaderAware, ApplicationContextAware {
private ApplicationContext applicationContext;
#Override
public EmbeddedServletContainer getEmbeddedServletContainer(ServletContextInitializer... initializers) {
DeploymentManager manager = createDeploymentManager(initializers);
int port = getPort();
if (port == 0) {
port = SocketUtils.findAvailableTcpPort(40000);
}
Undertow.Builder builder = createBuilder(port);
Map<String, Object> handlers = applicationContext.getBeansWithAnnotation(BlockingHandler.class);
return new UndertowEmbeddedServletContainer(builder, manager, getContextPath(),
port, port >= 0, handlers);
}
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}
...
override UndertowEmbeddedServletContainer.class
public UndertowEmbeddedServletContainer(Builder builder, DeploymentManager manager,
String contextPath, int port, boolean autoStart, Map<String, Object> handlers) {
this.builder = builder;
this.manager = manager;
this.contextPath = contextPath;
this.port = port;
this.autoStart = autoStart;
this.handlers = handlers;
}
private Undertow createUndertowServer() {
try {
HttpHandler servletHandler = this.manager.start();
String path = this.contextPath.isEmpty() ? "/" : this.contextPath;
PathHandler pathHandler = Handlers.path().addPrefixPath(path, servletHandler);
for(Entry<String, Object> entry : handlers.entrySet()){
Annotation annotation = entry.getValue().getClass().getDeclaredAnnotation(BlockingHandler.class);
System.out.println(((BlockingHandler) annotation).contextPath());
pathHandler.addPrefixPath(((BlockingHandler) annotation).contextPath(), (HttpHandler) entry.getValue());
}
this.builder.setHandler(pathHandler);
return this.builder.build();
}
catch (ServletException ex) {
throw new EmbeddedServletContainerException(
"Unable to start embdedded Undertow", ex);
}
}
set initializer to the application context
public static void main(String[] args) {
new SpringApplicationBuilder(Application.class).initializers(new UndertowInitializer()).run(args);
}
finaly create a HttpHandler that dispatch to worker thread
#BlockingHandler(contextPath = "/blocking/test")
public class DatabaseHandler implements HttpHandler {
#Autowired
private EchoService echoService;
#Override
public void handleRequest(HttpServerExchange httpServerExchange) throws Exception {
if(httpServerExchange.isInIoThread()){
httpServerExchange.dispatch();
}
echoService.getMessage("my message");
}
}
As you can see, my "solution" is really heavy, and i would really appreciate any help to simplify it a lot.
Thank you
You don't need to do anything.
Spring Boot's default Undertow configuration uses Undertow's ServletInitialHandler in front of Spring MVC's DispatcherServlet. This handler performs the exchange.isInIoThread() check and calls dispatch() if necessary.
If you place a breakpoint in your #Controller, you'll see that it's called on a thread named XNIO-1 task-n which is a worker thread (the IO threads are named XNIO-1 I/O-n).
I am new to spring and creating an web application ,
I want to redirect to login page always when user is not authenticated and without using spring security.xml??
Is it possible with session management??
A simple way would be to use a 'HandlerInterceptorAdapator':
public class CheckUserInterceptor extends HandlerInterceptorAdapter {
#Resource
private UserSession userSession;
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
Object handler) throws IOException {
if (request.getServletPath().equals("/login.htm")) {
return true;
}
String username = userSession.getUsername();
// If the username has not been set by the login controller
if (username != null) {
return true;
} else {
response.sendRedirect("login.htm");
return false;
}
}
}
In this case you need to declare the interceptor in the Spring XML file:
<mvc:interceptors>
<bean class="fr.unilim.msi.dad.web.mvc.CheckUserInterceptor" />
</mvc:interceptors>
Another approach, if for instance your Spring MVC controller are not configured to handle all requests, is to use a filter at the servlet level:
public class AccessControlFilter implements Filter {
#Override
public void init(FilterConfig filterConfig) throws ServletException {
}
#Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpSession session = ((HttpServletRequest) request).getSession(true);
User user = (User) session.getAttribute("user");
if (user == null) {
String urlRoot = ((HttpServletRequest) request).getContextPath();
((HttpServletResponse)response).sendRedirect(urlRoot + "/login.jsp");
} else {
chain.doFilter(request, response);
}
}
#Override
public void destroy() {
}
}
I guess you can do something like below in your login controller:
if(isUserAuthenticated())
{
return "home";
}
else
{
session.invalidate();
return "redirect:login";
}