I’m using DWR 3.0.0-rc2 and Spring 3.1.1.RELEASE. I was wondering if its possible to validate my #DataTransferObject input object using the Spring style “#Valid” (javax.validation.Valid) annotation. My specific question is, if this is possible and I set up my remote call like so …
#RemoteMethod
#Override
public String myRemoteMethod(#Valid final MyDto request)
{
how do I test to see if the input object (request) is valid and then throw a corresponding set of errors back to the client?
Thanks, - Dave
This looks like a good case to apply some AOP. One way is to create a #Before aspect that inspects the called arguments to see if they are annotated with #Valid, and if so trigger the validation for that argument and treat the results.
The code of this aspect would look like this:
#Aspect
public class ValidatingAspect {
Validator validator;
public ValidatingAspect() {
Configuration<?> configuration = Validation.byDefaultProvider().configure();
ValidatorFactory factory = configuration.buildValidatorFactory();
this.validator = factory.getValidator();
}
#Before("execution(* com.yourpackage..*.*(..))")
public void validateBefore(JoinPoint jp) throws Throwable {
Object[] args = jp.getArgs();
MethodSignature ms = (MethodSignature) jp.getSignature();
Method m = ms.getMethod();
Annotation[][] parameterAnnotations = m.getParameterAnnotations();
for (int i = 0; i < parameterAnnotations.length; i++) {
Annotation[] annotations = parameterAnnotations[i];
for (Annotation annotation : annotations) {
if (annotation.annotationType() == Valid.class) {
Set<ConstraintViolation<T>> constraintViolations = validator.validate(jp.getArgs()[i]);
... handle validation results ...
}
}
}
}
}
Related
I have this Spring boot application.properties
list1=valueA,valueB
list2=valueC
list3=valueD,valueE
topics=list1,list2,list3
What I'm trying to do is to use in the topics element of #KafkaListener annotation the values of the values of topics property
Using the expression
#KafkaListener(topics={"#{'${topics}'.split(',')}"})
I get list1,list2,list3 as separated string
How can I loop on this list in order to get valueA,valueB,valueC,valueD,valueE?
Edit: I must parse topics properties in order that #KafkaListener registers for consuming message from topics valueA,valueB,valueC, etc.
I read that is possible call a method in this way:
#KafkaListener(topics="#parse(${topics})")
So, I wrote this method:
public String[] parse(String s) {
ExpressionParser parser = new SpelExpressionParser();
return Arrays.stream(s.split(",").map(key -> (String)(parser.parse(key).getValue())).toArray(String[]::new);
}
But the parse method is not invoked
So, I tried directly to do this into annotations
in this way:
#KafkaListener(topics="#{Arrays.stream('${topics}'.split(',')).map(key->${key}).toArray(String[]::new)}")
But also this solution give me errors.
Edit 2:
Modifying in this way the method is invoked
#KafkaListener(topics="parse()")
#Bean
public String[] parse(String s) {
...
}
The problems is how to get "topics" props inside the method
You can't invoke arbitrary methods like that; you need to reference a bean #someBean.parse(...); using #parse requires registering a static method as a function.
However, this works for me and is much simpler:
list1=valueA,valueB
list2=valueC
list3=valueD,valueE
topics=${list1},${list2},${list3}
and
#KafkaListener(id = "so64390079", topics = "#{'${topics}'.split(',')}")
EDIT
If you can't use placeholders in topics, this works...
#SpringBootApplication
public class So64390079Application {
public static void main(String[] args) {
SpringApplication.run(So64390079Application.class, args);
}
#KafkaListener(id = "so64390079", topics = "#{#parser.parse('${topics}')}")
public void listen(String in) {
System.out.println(in);
}
}
#Component
class Parser implements EnvironmentAware {
private Environment environmment;
#Override
public void setEnvironment(Environment environment) {
this.environmment = environment;
}
public String[] parse(String[] topics) {
StringBuilder sb = new StringBuilder();
for (String topic : topics) {
sb.append(this.environmment.getProperty(topic));
sb.append(',');
}
return StringUtils.commaDelimitedListToStringArray(sb.toString().substring(0, sb.length() - 1));
}
}
I am using Spring AOP for profiling method execution time. My methods uses Spring WebFlux and returns a Mono of various types viz. Map, List , custom objects of Java classes. But jointPoint.proceed() in #Around advice returns object. How can I return the same Mono from doAround method.
The method whose execution time I want to know is as follows :
public Mono<Map<Integer, Car>> getCarObject(List<Integer> cardIds) {
if (cardIds == null || cardIds.isEmpty()) {
return Mono.fromCallable(() -> new HashMap<>());
}
return Mono.fromCallable(() -> listingClient.getCarObject(carIds).getData());
}
My aspect class is as follows :
#Aspect
#Configuration
public class Demo {
private Logger logger = LoggerFactory.getLogger(this.getClass());
#Pointcut("execution(* com.Car.*.mediators.*.*(..))")
public void feignClientPointcut() {
}
#Around("feignClientPointcut()")
public void doAround(ProceedingJoinPoint joinPoint) throws Throwable {
long start = System.currentTimeMillis();
Object object = joinPoint.proceed();
long end = System.currentTimeMillis();
long time = end - start;
logger.error("Around Method Name = {}",joinPoint.getSignature().getName());
logger.error("Around time :{}",time);
}
}
How can I return the same Mono from doAround method. Because on returning Mono<object> the caller function of method throws an error as it expects a Map not a object ?
My webservice receives an xml from a third-party source, which contains a !DOCTYPE declaration. Therefore I must use the second method in my controller to parse the xml document, the first one gives me this exception:
Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Could not unmarshal to [class com.example.MeterBusXml]: null; nested exception is javax.xml.bind.UnmarshalException
- with linked exception:
[org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 48; DOCTYPE is disallowed when the feature "http://apache.org/xml/features/disallow-doctype-decl" set to true.]
I have no control over the application which posts the xml, so I must adapt my webservice to parse it with the dtd.
My question is, what is the spring framework's way of injecting the EntityResolver into every XMLReader instance?
#RestController
public class MeterBusDataController {
#RequestMapping (
consumes = APPLICATION_XML_VALUE,
method = POST,
path = "/meterbus1"
)
public void method1(#RequestBody MeterBusXml xml) {
System.out.println(xml);
}
#RequestMapping(
method = POST,
path = "/meterbus2"
)
public void method2(HttpServletRequest rq) throws IOException, ParserConfigurationException, SAXException, JAXBException {
JAXBContext jc = newInstance(MeterBusXml.class);
Unmarshaller um = jc.createUnmarshaller();
SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setNamespaceAware(true);
spf.setValidating(true);
SAXParser sp = spf.newSAXParser();
XMLReader xr = sp.getXMLReader();
xr.setEntityResolver(new EntityResolver() {
#Override
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
return new InputSource(new StringReader(""));
}
});
BufferedReader reader = rq.getReader();
InputSource inputSource = new InputSource(reader);
SAXSource saxSource = new SAXSource(xr, inputSource);
MeterBusXml xml = (MeterBusXml)um.unmarshal(saxSource);
System.out.println(xml);
}
}
See the following document for an example of the mbus.xml I'm trying to unmarshal.
http://prevodniky.sk/products/product_EthMBus_common/download/Ethernet_converters_exports_v1_02_EN.pdf
I've found the root of the problem. First I tried to create and configure a Jaxb2Marshaller bean, but that did not work out. Then I realized, I need a HttpMessageConverter, so I had to override the extendMessageConverters method in the WebMvcConfigurerAdapter class, and set the required properties on Jaxb2RootElementHttpMessageConverter. This message converter does not use a Jaxb2Marshaller, but it's internal workings are very similar.
setSupportDtd(true) is required, to force the parser to accept the !DOCTYPE declaration.
setProcessExternalEntities(false) is required, because if this property is false, then the converter uses a blank EntityResolver, just as I did in method2.
#Configuration
public class WebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void extendMessageConverters(List<HttpMessageConverter<Jaxb2RootElementHttpMessageConverter?>> converters) {
for (final Iterator<HttpMessageConverter<?>> iterator = converters.iterator(); iterator.hasNext();) {
HttpMessageConverter<?> next = iterator.next();
if (next instanceof Jaxb2RootElementHttpMessageConverter) {
Jaxb2RootElementHttpMessageConverter jaxbConverter = (Jaxb2RootElementHttpMessageConverter) next;
jaxbConverter.setProcessExternalEntities(false);
jaxbConverter.setSupportDtd(true);
}
}
}
}
I am working with Spring-websocket and I have the following problem:
I am trying to put a placeholder inside a #MessageMapping annotation in order to get the url from properties. It works with #RequestMapping but not with #MessageMapping.
If I use this placeholder, the URL is null. Any idea or suggestion?
Example:
#RequestMapping(value= "${myProperty}")
#MessageMapping("${myProperty}")
Rossen Stoyanchev added placeholder support for #MessageMapping and #SubscribeMapping methods.
See Jira issue: https://jira.spring.io/browse/SPR-13271
Spring allows you to use property placeholders in #RequestMapping, but not in #MessageMapping. This is 'cause the MessageHandler. So, we need to override the default MessageHandler to do this.
WebSocketAnnotationMethodMessageHandler does not support placeholders and you need add this support yourself.
For simplicity I just created another WebSocketAnnotationMethodMessageHandler class in my project at the same package of the original, org.springframework.web.socket.messaging, and override getMappingForMethod method from SimpAnnotationMethodMessageHandler with same content, changing only how SimpMessageMappingInfo is contructed using this with this methods (private in WebSocketAnnotationMethodMessageHandler):
private SimpMessageMappingInfo createMessageMappingCondition(final MessageMapping annotation) {
return new SimpMessageMappingInfo(SimpMessageTypeMessageCondition.MESSAGE, new DestinationPatternsMessageCondition(
this.resolveAnnotationValues(annotation.value()), this.getPathMatcher()));
}
private SimpMessageMappingInfo createSubscribeCondition(final SubscribeMapping annotation) {
final SimpMessageTypeMessageCondition messageTypeMessageCondition = SimpMessageTypeMessageCondition.SUBSCRIBE;
return new SimpMessageMappingInfo(messageTypeMessageCondition, new DestinationPatternsMessageCondition(
this.resolveAnnotationValues(annotation.value()), this.getPathMatcher()));
}
These methods now will resolve value considering properties (calling resolveAnnotationValues method), so we need use something like this:
private String[] resolveAnnotationValues(final String[] destinationNames) {
final int length = destinationNames.length;
final String[] result = new String[length];
for (int i = 0; i < length; i++) {
result[i] = this.resolveAnnotationValue(destinationNames[i]);
}
return result;
}
private String resolveAnnotationValue(final String name) {
if (!(this.getApplicationContext() instanceof ConfigurableApplicationContext)) {
return name;
}
final ConfigurableApplicationContext applicationContext = (ConfigurableApplicationContext) this.getApplicationContext();
final ConfigurableBeanFactory configurableBeanFactory = applicationContext.getBeanFactory();
final String placeholdersResolved = configurableBeanFactory.resolveEmbeddedValue(name);
final BeanExpressionResolver exprResolver = configurableBeanFactory.getBeanExpressionResolver();
if (exprResolver == null) {
return name;
}
final Object result = exprResolver.evaluate(placeholdersResolved, new BeanExpressionContext(configurableBeanFactory, null));
return result != null ? result.toString() : name;
}
You still need to define a PropertySourcesPlaceholderConfigurer bean in your configuration.
If you are using XML based configuration, include something like this:
<context:property-placeholder location="classpath:/META-INF/spring/url-mapping-config.properties" />
If you are using Java based configuration, you can try in this way:
#Configuration
#PropertySources(value = #PropertySource("classpath:/META-INF/spring/url-mapping-config.properties"))
public class URLMappingConfig {
#Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
}
Obs.: in this case, url-mapping-config.properties file are in a gradle/maven project in src\main\resources\META-INF\spring folder and content look like this:
myPropertyWS=urlvaluews
This is my sample controller:
#Controller
public class WebSocketController {
#SendTo("/topic/test")
#MessageMapping("${myPropertyWS}")
public String test() throws Exception {
Thread.sleep(4000); // simulated delay
return "OK";
}
}
With default MessageHandler startup log will print something like this:
INFO: Mapped "{[/${myPropertyWS}],messageType=[MESSAGE]}" onto public java.lang.String com.brunocesar.controller.WebSocketController.test() throws java.lang.Exception
And with our MessageHandler now print this:
INFO: Mapped "{[/urlvaluews],messageType=[MESSAGE]}" onto public java.lang.String com.brunocesar.controller.WebSocketController.test() throws java.lang.Exception
See in this gist the full WebSocketAnnotationMethodMessageHandler implementation.
EDIT: this solution resolves the problem for versions before 4.2 GA. For more information, see this jira.
Update :
Now I understood what you mean, but I think that is not possible(yet).
Documentation does not mention anything related to Path mapping URIs.
Old answer
Use
#MessageMapping("/handler/{myProperty}")
instead of
#MessageMapping("/handler/${myProperty}")
And use it like this:
#MessageMapping("/myHandler/{username}")
public void handleTextMessage(#DestinationVariable String username,Message message) {
//do something
}
#MessageMapping("/chat/{roomId}")
public Message handleMessages(#DestinationVariable("roomId") String roomId, #Payload Message message, Traveler traveler) throws Exception {
System.out.println("Message received for room: " + roomId);
System.out.println("User: " + traveler.toString());
// store message in database
message.setAuthor(traveler);
message.setChatRoomId(Integer.parseInt(roomId));
int id = MessageRepository.getInstance().save(message);
message.setId(id);
return message;
}
Suppose I have a Website that is used in normal mode (browser) and in some other mode, like a MobileView mode (inside a mobile app). For each Controller I create, there might be correspondent controller for MobileView, processing the same url.
The easiest solution is to create ifs in all the Controllers that have MobileView logic. Another solution would be to use a correspondent url for MobileView (similar to the normal url) and two separate Controllers (possible where one extends from another; or use some other way to recycle common code)
But, a more elegant solution would be to have some extra annotations, like #SupportsMobileView (to mark a controller, and tell the app that this will have a correspondent MobileView Controller) and #MobileViewController (to mark a second controller, and tell the app that this controller needs to run immediately after the initial controller marked with #SupportsMobileView). The link between a normal controller and a MobileView controller would be through the url they process (defined with #RequestMapping).
Is it possible to extend Spring MVC (A)? Where to inject new annotation scanners (B) and annotation handlers / component handlers (C)? How should the MobileView controller be executed (D) (right now I am thinking that it could be executed through AOP, where the new handler of my new controller type programatically creates a Join-Point on the corresponding normal controller)
Note that I did not mention how this MobileView mode is triggered and detected. Let's just say that there a Session boolean variable (flag) for that.
Critics on any points (A), (B), (C) or (D) are welcomed, as well as technical hints and alternative solution to any point or the whole solution.
HandlerInterceptor can be used to intercept the RequestMapping handling. This is a simple example how to configure and implement one.
You can check for your session variable and will have a bunch of methods that will allow you to do custom processing or just exchange the view from the normal controller handling with your mobile view.
Ok, warnings:
this is only a proof of concept of what I understood must be done so:
+#MobileViewEnable and #MobileView annotated (and related) methods need to stay in the same controller
+there's no check for the httpAction used
+the two methods must have the same signature
+mobileView annotation value and requestMapping annotation value must be equals and uniques
+the logic inside callYourLogic(..) defines which method is going to be called, at the moment there's a very simple logic that check if exist the parameter ("mobile") in the request, just to test
+this code is not intended to be used as is (at all)
+don't know if it works at all outside my pc (joke :D, ehm..)
SO:
Annotations:
#Retention(RetentionPolicy.RUNTIME)
public #interface MobileView {
String value() default "";
}
#Retention(RetentionPolicy.RUNTIME)
public #interface MobileViewEnable {
}
ExampleController:
#Controller
public class MainController extends BaseController {
private final static Logger logger = LoggerFactory.getLogger(MainController.class);
private final static String PROVA_ROUTE = "prova";
#MobileViewEnable
#RequestMapping(PROVA_ROUTE)
public String prova() {
logger.debug("inside prova!!!");
return "provaview";
}
#MobileView(PROVA_ROUTE)
public String prova2() {
logger.debug("inside prova2!!!");
return "prova2view";
}
}
Aspect definition:
<bean id="viewAspect" class="xxx.yyy.ViewAspect" />
<aop:config>
<aop:pointcut expression="#annotation(xxx.yyy.MobileViewEnable)" id="viewAspectPointcut" />
<aop:aspect ref="viewAspect" order="1">
<aop:around method="around" pointcut-ref="viewAspectPointcut" arg-names="viewAspectPointcut"/>
</aop:aspect>
</aop:config>
Aspect implementation:
public class ViewAspect implements BeforeAdvice, ApplicationContextAware {
private final static Logger logger = LoggerFactory.getLogger(ViewAspect.class);
private ApplicationContext applicationContext;
public Object around(ProceedingJoinPoint joinPoint) {
Method mobileViewAnnotatedMethod = null;
HttpServletRequest request = getCurrentHttpRequest();
String controllerName = getSimpleClassNameWithFirstLetterLowercase(joinPoint);
Object[] interceptedMethodArgs = getInterceptedMethodArgs(joinPoint);
String methodName = getCurrentMethodName(joinPoint);
Method[] methods = getAllControllerMethods(joinPoint);
Method interceptedMethod = getInterceptedMethod(methods, methodName);
String interceptedMethodRoute = getRouteFromInterceptedMethod(interceptedMethod);
if (callYourLogic(request)) {
mobileViewAnnotatedMethod = getMobileViewAnnotatedMethodWithRouteName(methods, interceptedMethodRoute);
if (mobileViewAnnotatedMethod != null)
return invokeMethod(mobileViewAnnotatedMethod, interceptedMethodArgs, controllerName);
}
return continueInterceptedMethodExecution(joinPoint, interceptedMethodArgs);
}
private Object continueInterceptedMethodExecution(ProceedingJoinPoint joinPoint, Object[] interceptedMethodArgs) {
try {
return joinPoint.proceed(interceptedMethodArgs);
} catch (Throwable e) {
logger.error("unable to proceed with intercepted method call: " + e);
}
return null;
}
private Object[] getInterceptedMethodArgs(JoinPoint joinPoint) {
return joinPoint.getArgs();
}
private boolean callYourLogic(HttpServletRequest request) {
// INSERT HERE YOUR CUSTOM LOGIC (e.g.: is the server accessed from a mobile device?)
// THIS IS A STUPID LOGIC USED ONLY FOR EXAMPLE
return request.getParameter("mobile")!= null;
}
private HttpServletRequest getCurrentHttpRequest() {
return ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest();
}
private String invokeMethod(Method method, Object[] methodArgs, String className) {
if (method != null) {
try {
Object classInstance = getInstanceOfClass(method, className);
return (String) method.invoke(classInstance, methodArgs);
} catch (Exception e) {
logger.error("unable to invoke method" + method + " - " + e);
}
}
return null;
}
private Object getInstanceOfClass(Method method, String className) {
return applicationContext.getBean(className);
}
private Method getMobileViewAnnotatedMethodWithRouteName(Method[] methods, String routeName) {
for (Method m : methods) {
MobileView mobileViewAnnotation = m.getAnnotation(MobileView.class);
if (mobileViewAnnotation != null && mobileViewAnnotation.value().equals(routeName))
return m;
}
return null;
}
private String getRouteFromInterceptedMethod(Method method) {
RequestMapping requestMappingAnnotation = method.getAnnotation(RequestMapping.class);
if (requestMappingAnnotation != null)
return requestMappingAnnotation.value()[0];
return null;
}
private String getCurrentMethodName(JoinPoint joinPoint) {
return joinPoint.getSignature().getName();
}
private Method[] getAllControllerMethods(JoinPoint joinPoint) {
return joinPoint.getThis().getClass().getSuperclass().getMethods();
}
private String getSimpleClassNameWithFirstLetterLowercase(JoinPoint joinPoint) {
String simpleClassName = joinPoint.getThis().getClass().getSuperclass().getSimpleName();
return setFirstLetterLowercase(simpleClassName);
}
private String setFirstLetterLowercase(String simpleClassName) {
String firstLetterOfTheString = simpleClassName.substring(0, 1).toLowerCase();
String restOfTheString = simpleClassName.substring(1);
return firstLetterOfTheString + restOfTheString;
}
private Method getInterceptedMethod(Method[] methods, String lookingForMethodName) {
for (Method m : methods)
if (m.getName().equals(lookingForMethodName))
return m;
return null;
}
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}