how can i get correlationId? - spring-amqp

On my project(spring-rabbit..), Set fixed ReplyTo queue on template, I use convertSendAndReceive method for RPCs.
I understand that mekes correlationId automatically.
Can I set correlationId before using that method?
Here is Template.
#Bean
public RabbitTemplate rabbitTemplate() {
RabbitTemplate template = new RabbitTemplate(connectionFactory());
template.setMessageConverter(jsonMessageConverter());
template.setRoutingKey(AmqpConstants.JOB_QUEUE_NAME);
template.setExchange(AmqpConstants.JOB_EXCHANGE_NAME);
template.setQueue(AmqpConstants.JOB_QUEUE_NAME);
template.setReplyQueue(new Queue(AmqpConstants.JOB_REPORT_QUEUE_NAME));
template.setReplyTimeout(replyTimeoutMilliseoconds);
return template;
}
Code
jobReport = (ApiJobReport)rabbitTemplate.convertSendAndReceive(
AmqpConstants.JOB_EXCHANGE_NAME,
AmqpConstants.JOB_QUEUE_NAME,
jobMessage, new MessagePostProcessor() {
#Override
public Message postProcessMessage(Message message) throws AmqpException {
message.getMessageProperties().setCorrelationId("correlationid1234".getBytes());
return message;
}
});
In postProcessMessage, setting correlationId as "correlationid1234".
But RabbitMQ Management shows below.
Message properties :
correlation_id: 23316fe6-0c15-46f6-9bed-5f3abf22a594
priority: 0
delivery_mode: 2
headers:
TypeId: com.example.model.apijob
content_encoding: UTF-8
content_type: application/json
As shown result, set correlationId has changed to RabbitTemplate messageTag value(UUID). Im watching RabbitTemplate source but I dont understand why it makes change to correlationId if correlationKey is null.
RabbitMQ Management

If you use sendAndReceive() (rather then convertSendAndReceive()); if you set a correlationId message property, the template saves it off; uses its own correlationId in the outbound message and restores the original correlationId in the reply message.
It's not clear what you mean in the context of convertSendAndReceive(); you can't set the correlationId before you call it because there is no message until the conversion takes place.
You could set it in a MessagePostProcessor but it won't achieve very much.
Perhaps if you could explain what you are trying to do, I can make some other suggestion.

Related

How to set consumer priority with AmqpTemplate

I'm using the spring-boot-starter-amqp library to:
Wait indefinitely until a message can be received.
Process the message, which may take several minutes.
Terminate the program
I also would like to the set the consumer priority. However, I don't know how to set the x-priority consumer argument, as the documentation only mentions how to do this with an asynchronous consumer, not with AmqpTemplate or RabbitTemplate. Any help would be appreciated.
ApplicationRunner class:
private final AmqpTemplate template;
private final ApplicationContext applicationContext;
...
#Override
public void run(ApplicationArguments args) {
Message message = template.receive("analyses", -1);
if (message == null) throw new IllegalStateException("No message received");
byte[] body = message.getBody();
// todo: process the message
System.out.printf("[x] Received '%s'%n", new String(body, StandardCharsets.UTF_8));
context.close();
}
In a configuration class:
#Bean
public RabbitTemplate amqpTemplate(final ConnectionFactory connectionFactory) {
return new RabbitTemplate(connectionFactory);
}
It is not currently supported; the consumer is created in a private method createConsumer() which doesn't pass any arguments to basicConsume().
Please open a new feature issue on GitHub; it won't be difficult to implement and we have releases planned for next week.
https://github.com/spring-projects/spring-amqp/issues

StackOverflowException in spring-data-jpa app with spring-security AuditorAware

I have a really nasty StackOverflowException in my spring backend, that I need help with. This is not going to be solved easily. I really hope to find some help here.
Most parts of my backend work. I can query my REST interface for models, they are nicely returned by spring-hateoas, GET, PUT and POST operations work. But one exception: When I try to update an existing DelegationModel, then I run into an endless StackOverflowException.
Here is my DelegetionModel.java class. Please mark, that delegation model actually doesn't have any property annotated with #CreatedBy!
#Entity
#Data
#NoArgsConstructor
#RequiredArgsConstructor(suppressConstructorProperties = true) //BUGFIX: https://jira.spring.io/browse/DATAREST-884
#EntityListeners(AuditingEntityListener.class) // this is necessary so that UpdatedAt and CreatedAt are handled.
#Table(name = "delegations")
public class DelegationModel {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
public Long id;
/** Area that this delegation is in */
#NonNull
#NotNull
#ManyToOne
public AreaModel area;
/** reference to delegee that delegated his vote */
#NonNull
#NotNull
#ManyToOne
public UserModel fromUser;
/** reference to proxy that receives the delegation */
#NonNull
#NotNull
#ManyToOne
public UserModel toProxy;
#CreatedDate
#NotNull
public Date createdAt = new Date();
#LastModifiedDate
#NotNull
public Date updatedAt = new Date();
}
As described in the Spring-data-jpa doc I implemented the necessary AuditorAware interface, which loads the UserModel from the SQL DB. I would have expected that this AuditorAware interface is only called for models that have a field annotated with #CreatedBy.
#Component
public class LiquidoAuditorAware implements AuditorAware<UserModel> {
Logger log = LoggerFactory.getLogger(this.getClass()); // Simple Logging Facade 4 Java
#Autowired
UserRepo userRepo;
#Override
public UserModel getCurrentAuditor() {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
if (authentication == null || !authentication.isAuthenticated()) {
log.warn("Cannot getCurrentAuditor. No one is currently authenticated");
return null;
}
User principal = (org.springframework.security.core.userdetails.User) authentication.getPrincipal();
UserModel currentlyLoggedInUser = userRepo.findByEmail(principal.getUsername()); // <<<<======= (!)
return currentlyLoggedInUser;
} catch (Exception e) {
log.error("Cannot getCurrentAuditor: "+e);
return null;
}
}
}
Now I update a DelegationModel in my UserRestController. The functional "Scrum User Story" here is:
As a user I want to be able to store a delegation so that I can forward my right to vote to my proxy.
#RestController
#RequestMapping("/liquido/v2/users")
public class UserRestController {
[...]
#RequestMapping(value = "/saveProxy", method = PUT, consumes="application/json")
#ResponseStatus(HttpStatus.CREATED)
public #ResponseBody String saveProxy(
#RequestBody Resource<DelegationModel> delegationResource,
//PersistentEntityResourceAssembler resourceAssembler,
Principal principal) throws BindException
{
[...]
DelegationModel result = delegationRepo.save(existingDelegation);
[...]
}
[...]
}
For some reason, that I cannot see, this actualy calls the AuditorAware implementation above. The problem is now, that my LqiuidoAuditorAware implementation is called again and again in and endless loop. It seems that the query for the UserModel inside LiquidoAuditorAware.java calls the LiquidoAuditorAware again. (Which is unusual, because that is only a read operation from the DB.)
Here is the full ThreadDump as a Gist
All the code can by found in this github repo
I'd really apriciate any help here. I am searching in the dark :-)
The reason for the behavior you see is that the AuditorAware implementation is called from within a JPA #PrePersist/#PreUpdate callback. You now issue a query by calling findByEmail(…), which triggers the dirty-detection again, which in turn causes the flushing to be triggered and thus the invocation of the callbacks.
The recommended workaround is to keep an instance of the UserModel inside the Spring Security User implementation (by looking it up when the UserDetailsService looks up the instance on authentication), so that you don't need an extra database query.
Another (less recommended) workaround could be to inject an EntityManager into the AuditorAware implementation, call setFlushMode(FlushModeType.COMMIT) before the query execution and reset it to FlushModeType.AUTO after that, so that the flush will not be triggered for the query execution.

Why is a VerifyError thrown when publishing changes with a decorated HtmlResponseWriter

I am facing a problem when publishing changes to WebSphere with JSF2 (Myfaces 2.0.12).
Everytime I publish a change to my local server (WebSphere) I am getting a java.lang.VerifyError. After a full restart of the server the application runs smoothly with my changes.
java.lang.VerifyError: com/sun/faces/renderkit/html_basic/HtmlResponseWriter.startElement(Ljava/lang/String;Ljavax/faces/component/UIComponent;)V
The StackTrace indicates that something is wrong with the ResponseWriter and indeed we changed a little bit there ;-)
For accessibility-reasons I have to have full controll of the HTML so I need custom HtmlRenderers. To reduce duplicate code I decorated the ResponseWriter I get from the FacesContext with my own, and provide additional convenience-methods on top.
public class CustomResponseWriter<T extends UIInput & MyFormdataInterface> extends HtmlResponseWriter
{
public CustomResponseWriter(ReponseWriter writer){
super(writer, writer.getContentType(), writer.getCharacterEncoding());
}
public writeFancy(T component)
{
...
writeText(component.getMyFanceAttribute(), null);
...
}
}
As I said, the code runs fine after the server was restarted so I assume the code is correct. But on the other side, this error occurs only on pages where I use this CustomReponseWriter.
Is there anything wrong with the idea of decorating the ResponseWriter in a new class? Or might this just be a problem in WebSphere?
As lu4242 mentioned in his comment, I changed the implementation from decorator to a delegate and the problem disappeared. It would be nice to understand why this happens but for now here is the changed code (I dont like the verbose code from the delegate in this case but as long as it works).
public class CustomResponseWriter<T extends UIInput & MyFormdataInterface> extends ResponseWriter
{
private ResponseWriter delegateWriter;
public CustomResponseWriter(ReponseWriter writer){
this.delegateWriter = writer;
}
public writeFancy(T component)
{
...
writeText(component.getMyFanceAttribute(), null);
...
}
public String getContentType()
{
this.delegateWriter.getContentType();
}
//... and so on for all methods from ResponseWriter...
}
}

Struts2 - Implementing ModelDriven - Create an interceptor that accesses the model properties

I'm relatively new to Struts2.
I've started using ModelDriven to reduce overhead in development.
I wanted to write an interface to modify a property before it gets to the action but I don't see how you can access the properties of a class that implements ModelDriven for the Model.
I can see how things like validate() can work as they are in the actual action class.
I changed the design to encapsulate the logic behind the service anyways but still would like to know if this is possible.
We're doing everything by ajax/json so I find modeldriven helps quite a lot - not sure if there is a better alternative though!
Edit - code example:
Trying to replace a message with a message in a template to use in an email body.
public class EmailActionImpl implements EmailAction {
private Email email=new Email();
private EmailService emailService;
public Email getModel(){
return email;
}
[... getters and setters ...]
public String execute(){
logger.info("Email action is sendind an email...");
try{
emailService.sendNewMail(email);
}catch(Exception e){
logger.error("Email not sent: " + e.getMessage());
return "failure";
}
return "success";
}
}
Email model something like this
#Entity
#Table(name="email")
public class Email {
private Long id;
private String from;
private String to;
private String message;
private String templateType;
[...]
}
I would like an interceptor preprocessor to replace email.message.
Should look something like this but action.getMessage/setMessage aren't available.
public class SimpleInterceptor extends AbstractInterceptor {
public String intercept(ActionInvocation invocation) throws Exception {
EmailAction action = (EmailAction)invocation.getAction();
action.setMessage(MessageTemplateFactoryImpl(action.getMessage(), action.getTemplateType());
return invocation.invoke();
}
}
If you still want to implement an interceptor to work on a particular set of models then you will check if the Action implements ModelDriven. Via reflection (or Apache bean utils) you can derive the particular model in question, to determine if your interceptor applies and then act on it accordingly.

jedis pubsub and timeouts: how to listen infinitely as subscriber?

I'm struggling with the concept of creating a Jedis-client which listens infinitely as a subscriber to a Redis pubsub channel and handles messages when they come in.
My problem is that after a while of inactivity the server stops responding silently. I think this is due to a timeout occurring on the Jedis-client I subscribe with.
Would this likely indeed be the case? If so, is there a way to configure this particular Jedis-client to not timeout? (While other Jedispools aren't affected with some globally set timeout)
Alternatively, is there another (best practice) way of what I'm trying to achieve?
This is my code, (modified/ stripped for display) :
executed during web-server startup:
new Thread(AkkaStarter2.getSingleton()).start();
AkkaStarter2.java
private Jedis sub;
private AkkaListener akkaListener;
public static AkkaStarter2 getSingleton(){
if(singleton==null){
singleton = new AkkaStarter2();
}
return singleton;
}
private AkkaStarter2(){
sub = new Jedis(REDISHOST, REDISPORT);
akkaListener = new AkkaListener();
}
public void run() {
//blocking
sub.psubscribe(akkaListener, AKKAPREFIX + "*");
}
class AkkaListener extends JedisPubSub {
....
public void onPMessage(String pattern, String akkaChannel,String jsonSer) {
...
}
}
Thanks.
ermmm, the below solves it all. Indeed it was a Jedis thing
private AkkaStarter2(){
//0 specifying no timeout.. Overlooked this 100 times
sub = new Jedis(REDISHOST, REDISPORT,0);
akkaListener = new AkkaListener();
}

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