Convention in java

Class Group Names

In Java, class names generally should be nouns, in title case with the first letter of each separate word capitalized . and interface names generally should be adjectives, in title case with the first letter of each separate word capitalized.

Java class names cannot start with numbers .

Class names should be nouns, in mixed case with the first letter of each internal word capitalized . Try to keep your class names simple and descriptive. Use whole words-avoid acronyms and abbreviations (unless the abbreviation is much more widely used than the long form, such as URL or HTML).