Inefficient Usages of Java Collections

[FastAtlas]

Hi,

We find that there are several inefficient usages of Java Collections:

1. There is no iteration occurring upon a LinkedHashMap, thus the insertion order does not matter. We recommend replacing it with a HashMap.
2. ArrayList is inserted before an iteration, while multiple memory reallocation might occur when the size of the list exceeds its capacity. We recommend replacing it with a LinkedList.

We discovered the above inefficient usages of containers by our tool Ditto. The patch is submitted in #134. Could you please check and accept it? We have tested the patch on our PC. The patched program works well.

Bests

Ditto