Max name length of variable or method in Java

java naming specifications name-length
talg picture talg · Mar 30, 2009 · Viewed 38.1k times · Source

Is there a max length for class/method/variable names in Java? the JLS doesn't seem to mention that. I know very long names are problematic anyway from code readability and maintainability perspective, but just out of curiosity is there a limitation (I guess class names might be limited by the file system maximal file name limitation).

Answer

Uri picture Uri · Mar 30, 2009

If I'm not mistaken, the limit is not in the language itself but in the classfile format, which limits names to 64k, so for all practical intents and purposes identifier length is not a problem. Specifically, this is the definition of a constant string in the pool, which seems to imply the maximal length is 16 bit:

CONSTANT_Utf8_info {
    u1 tag;
    u2 length;
    u1 bytes[length];
}

Class names may be more of an issue for file systems, I agree, I'm not sure what's currently supported.

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