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Message:

Type Descriptors in Class Files

Posted by Bill Venners on June 01, 2000 at 11:26 PM

> Recently I received a runtime error indicating :
> "no signature matching Ljava/lang/Sting .....

> The error was present on an attempt to invoke a method with
> java.lang.String as a param.

> I am told that Ljava refers to an array of String.
> Does anyone know if this is true ?

Looks like you've been stung by a typo. Unless the typo is in
your forum post rather than your program, you've left out the
"r" in String.

"Ljava/lang/String;" is a type descriptor, the kind you'll find
in Java class files. It just means a reference type with the
name "java.lang.String". The descriptor for an array of String
would be: "[Ljava/lang/String;"

I describe type descriptors in chapter 6 of my JVM book, but
unfortunately I haven't yet posted that chapter to artima.com.
I plan to in the future, so check back from time to time if
you are interested. The online chapters are at:

http://www.artima.com/insidejvm/ed2/index.html

bv