Java leak check

1. Automatic conversions are converted in order from low to high. The priority relationships between different types of data are as follows:
Low---------------------------------------------> High
byte,short,char-> int, long, float---double

The format of the cast is to add "()" before the data that needs to be transformed, and then add the data type that needs to be converted in parentheses. Some of the data after the transformation operation, the accuracy will be lost, and some will be more accurate

From low to high do not need strong turn

Java leak check