The name of the Java naming conventions :( non-compliance, compilation errors do not occur)
- Package name: multi-word when all letters are lowercase: xxxyyyzzz
- Class name, interface name: multi-word, the first letter of all words capitalized: XxxYyyZzz
- Variable names, method names: multi-word, lowercase first letter of the first word, the second word began to capitalize the first letter of each word: xxxYyyZzz
- Constant name: All the letters are capitalized. When many words each word with an underscore: XXX_YYY_ZZZ