method-reference

So Java 8 introduces method references and the docs describe the four types . My question is what's the difference between the two instance types? Reference to an instance method of a particular object. Reference to an instance method of an arbitrary object of a particular type. Both refer to references but what's significantly different? Is it that the type inference used to resolve them is different? Is it significant that (in their examples) one is a closure and the other is a lambda? Is it something to do with the number of arguments on a method? Louis Wasserman 1) myString::charAt would

I am having trouble understanding the syntax for a method reference, where there are two parameters a and b , and the reference is to a method of a on b . For example I understand how Arrays.sort(personArray, comparators::compareByName); is equivalent to Arrays.sort(personArray, (o1, o2) -> comparators.compareByName(o1, o2)); because in that case the lambda parameters match the method call parameters (o1, o2) . Howevever for this lambda stream.sorted((o1, o2) -> o1.compareToIgnoreCase(o2)); my IDE tells me that is equivalent to: stream.sorted(String::compareToIgnoreCase); and I am not finding

Suppose there is a typical Java Bean: class MyBean { void setA(String id) { } void setB(String id) { } List<String> getList() { } } And I would like to create a more abstract way of calling the setters with the help of a BiConsumer: Map<SomeEnum, BiConsumer<MyBean, String>> map = ... map.put(SomeEnum.A, MyBean::setA); map.put(SomeEnum.B, MyBean::setB); map.put(SomeEnum.List, (myBean, id) -> myBean.getList().add(id)); Is there a way to replace the lambda (myBean, id) -> myBean.getList().add(id) with a chained method reference, something like (myBean.getList())::add or myBean::getList::add or

I am trying to use Java 8 method references in my code. There are four types of method references available. Static method reference. Instance Method (Bound receiver). Instance Method (UnBound receiver). Constructor reference. With Static method reference and Constructor reference i have no problem, but Instance Method (Bound receiver) and Instance Method (UnBound receiver) really confused me. In Bound receiver, we are using an Object reference variable for calling a method like: objectRef::Instance Method In UnBound receiver we are using Class name for calling a method like: ClassName:

I've noticed something weird about unhandled exceptions using Java 8 method reference. This is my code, using the lambda expression () -> s.toLowerCase() : public class Test { public static void main(String[] args) { testNPE(null); } private static void testNPE(String s) { Thread t = new Thread(() -> s.toLowerCase()); // Thread t = new Thread(s::toLowerCase); t.setUncaughtExceptionHandler((t1, e) -> System.out.println("Exception!")); t.start(); } } It prints "Exception", so it works fine. But when I change Thread t to use a method-reference (even IntelliJ suggests that): Thread t = new Thread