CODEWITHSUNDEEP
javaregexpackage
Philipp Spiess
Philipp Spiess

Reputation: 3271

Is it possible to write a regex to extract java package?

Is it possible to write a regex, which extractst the package path in a .java file?

Something like this:

package java.awt.event;
// java code

to this

java.awt.event

which i than can resolve to the folder location?

java/awt/event/

I don't know which characters a package can have, or if it's possible to add more than one package.

Upvotes: 3

Views: 4237

Answers (4)

Christopher Lawless
Christopher Lawless

Reputation: 1087

I know this is delayed but i would like to contribute this one i made which works reasonably well specifically for Android package names convention.

  (^[a-z]+[.][a-z]+[.][a-z]+($|[.][a-z]+$))

Upvotes: 0

Gwen
Gwen

Reputation: 11

This regexp works perfectly :

package\\s([a-zA-Z]\\w*)(\\.[a-zA-Z]\\w*)*;"\

to match :

  • "package"
  • whitespace
  • package definition starting with a non digit character
  • any sub package definition
  • ";"

Upvotes: 1

John B
John B

Reputation: 32969

"package\\s+([a-zA_Z_][\\.\\w]*);"

There can only be one package at the beginning of a java file. Only word characters and "." are allowed.

"package\\s+" => the work "package" followed by at least one space
"("           => start of capture
"[a-zA-Z_]"   => first character of package (doesn't include numeric digits)
"[\\.\\w]*"   => any number of word characters (a-zA-Z0-9_) plus the "." character
")"           => end of capture
";"           => end of line

Really this is not the best since it does not enforce that the first character of each folder not be a digit however it will work without fully enforcing rules. This being the case the following might be easier:

"package\\s+([\\w\\.]+);"

Upvotes: 12

ratchet freak
ratchet freak

Reputation: 48216

you can have only 1 package declaration and allowed syntax is the same as normal identifiers

"package ([\\w&&\\D]([\\w\\.]*[\\w])?);"

capture group 1 will have the package replace the . with file separators and you're there

Upvotes: 2

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