Summary
We saw how using an anonymous class will create a new instance and call it's constructor with invokespecial
.
We saw anonymous classes that close over variables have an extra argument on their constructor to capture that variable.
And we saw how Java lambdas use the invokedynamic
instruction to defer binding of the types and that a special lambda$
method handle is used to actually represent the lambda. This method handle has no arguments in this case and is invoked using invokestatic
making it a genuine function.
The lambda was created by the LambdaMetafactory
class which itself was the target of the invokedynamic
call.
When a lambda has arguments, we saw how the LambdaMetafactory
describes the argument to be passed into the lambda. The invokestatic
opcode is used to execute the lambda like before. But we also had a look at a method reference used in-lieu of a lambda. In this case, no lambda$
method handle was created and invokevirtual
was used to call the method directly...