将数据添加到Jersey中的Response对象

Question

I am trying to use an Aspect to add a timestamp to a javax.ws.rs.core.Response using an Around advice.

I'm new to Java and Jersey and I'm struggling to do this. The closest I have is this:

Object output = proceed();
Method method = ((MethodSignature) thisJoinPoint.getSignature()).getMethod();
Type type = method.getGenericReturnType();

if (type == Response.class)
{
    System.out.println("We have a response!");
    Response original = (Response) output;
    output = (Object)Response.ok(original.getEntity(String.class).toString()+ " " + Double.toString(duration)).build();
}

return output;

The kind of response produced is always an application/JSON . Basically I want to add another field to the JSON that says time:<val of duration> .

Answer 1

The easiest solution is to make all your entity classes extend an interface which has a method getTime() and setTime() and then you can set the time value in your interceptor as shown below.

public interface TimedEntity {
    long getTime();

    void setTime(long time);
}

Your actual entity

public class Entity implements TimedEntity {
    private long time;

    // Other fields, getters and setters here..

    @Override
    public long getTime() {
        return time;
    }

    @Override
    public void setTime(long time) {
        this.time = time;
    }
}

And your interceptor

Object output = proceed();
Method method = ((MethodSignature)thisJoinPoint.getSignature()).getMethod();
Type type = method.getGenericReturnType();

if (type == Response.class)
{
  System.out.println("We have a response!");
  Response original = (Response) output;
  if (original != null && original.getEntity() instanceof TimedEntity) {
    TimedEntity timedEntity = (TimedEntity) original.getEntity();
    timedEntity.setTime(duration);
  }

}else if (output instanceof TimedEntity) {
    TimedEntity timedEntity = (TimedEntity) output;
    timedEntity.setTime(duration);
}

return output;