Copy ‘XXXX‘ to effectively final temp variable

today , Used in projects lambda The expression encountered a problem ：

Copy 'standDatasMap' to effectively final temp variable

Which translates as ：xxxx Use valid final variables .

What does that mean ？

Let's have a look first ,lambda Rules for expressions ：

1. Only references to tags final The outer local variable of , That is to say, it can't be in lambda Internal modification of local variables defined outside the domain , Otherwise it will compile incorrectly .
2. Local variables may not be declared as final, But it must not be modified by the following code （ That is to say, recessive has final The semantics of the ）
3. It is not allowed to declare a parameter or local variable with the same name as a local variable .

Write an example for you , Simple scenario reappearance ：

reason ：

This is because lambda Expressions do not accept dynamic parameters .

Revised as follows ：

We can add one map, Used to receive dynamic parameters , This problem can be solved .