The following Java code appears to be fairly lengthy and somewhat repetitive. Can it be made more concise?
A myObjA = getObject(id, A.class);
if (myObjA != null) {
handleA(myObjA);
}
B myObjB = getObject(id, B.class);
if (myObjB != null) {
handleB(myObjB);
}
C myObjC = getObject(id, C.class);
if (myObjC != null) {
handleC(myObjC);
}
Forgot to mention. This is not running on Java 8 :(
Sure, thanks to the magic of java-8! Simply create this helper method:
private <T> static void getAndHandleIfNonNull(int id, Class<T> clazz, Consumer<T> handler) {
T t = getObject(id, clazz);
if (t != null) {
handler.accept(t);
}
}
And then call it:
getAndHandleIfNonNull(id, A.class, this::handleA);
getAndHandleIfNonNull(id, B.class, this::handleB);
getAndHandleIfNonNull(id, C.class, this::handleC);
Refining the other answers:
Optional.ofNullable(getObject(id, A.class)).ifPresent(this::handleA);
Optional.ofNullable(getObject(id, B.class)).ifPresent(this::handleB);
Optional.ofNullable(getObject(id, C.class)).ifPresent(this::handleC);
This is shorter and more concise.
How about making use of the new Java 8 features?
Optional.ofNullable(getObject(id,A.class)).ifPresent(myObjA -> handleA(myObjA));
Optional.ofNullable(getObject(id,B.class)).ifPresent(myObjB -> handleB(myObjB));
Optional.ofNullable(getObject(id,C.class)).ifPresent(myObjC -> handleC(myObjC));
Well, if you can put a null check fence in your handleX methods, your code becomes much more concise.
handleA(getObject(id, A.class));
handleB(getObject(id, B.class));
handleC(getObject(id, C.class));
