Java Lambda Iteration List from JPA -

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• why stream return no element? 1 answer

i found strange behaviour when using lambda jpa, seems java 8 lambda don't iterate when list object.

for example:

    list<myobject> list = anotherobject.getmyobjectlist(); // list      list.foreach(myobject -> system.out.println("not printed"));      system.out.println("size?: " + list.size()); // print size = 2 

i try list.stream().foreach() same results..

after hours of testing found trick

    list<myobject> copylist = new arraylist<>(list); // copy list      copylist.foreach(myobject -> system.out.println("omg printed!")); 

huh? ideas?, bug? or im doing wrong? entity clases working good, relations good... :)

thanks in advance :).

it know concrete class of list returned anotherobject.getmyobjectlist(). may have bug in iterator.

when copy arraylist using new arraylist<>(list), code constructor copies elements source list using toarray , copies new array that's contained within arraylist.

when call list.foreach, unless it's been overridden concrete class, ends calling default method foreach of iterable, implementation is:

default void foreach(consumer<? super t> action) {     objects.requirenonnull(action);     (t t : this) {         action.accept(t);     } } 

this standard enhanced-for loop here, nothing magic. loop implemented in terms of list's iterator. try writing out for-loop instead of calling list.foreach(lambda), or try calling list.iterator() , see how many elements out of it. if toarray works iteration techniques don't, seems bug in implementation of jpa list class's iterator.