Reduce the generation of Java garbage and reduce the amount of memory used

1. Use as few static variables as possible, as it will always consume memory,

2. Use as few string strings as possible for stitching and adding. Because a string is a fixed length, each addition creates a new temporary object, generates a garbage object, and uses StringBuffer as much as possible because the StringBuffer is variable length.

3. When the object is exhausted, the null value is used so that the JVM garbage collection will not be judged and recycled directly.

4. Try not to display the call System.GC ().

Reduce the generation of Java garbage and reduce the amount of memory used