1. A computer-implemented method, comprising: while a software application is executing to generate a source language user interface, extracting source language GUI component text of a GUI component that is embodied in a bytecode of said software application, said extracting including: identifying that a localizable method in said bytecode of said software application matches a method found in a class-method map; in response to the identifying, adding instructions associated with the localizable method to said bytecode; and extracting source language GUI component text from an input parameter of the localizable method; forming a localization pack file that includes said extracted source language GUI component text, wherein said localization pack file contains a plurality of key-value pairs, and wherein each key-value pair includes a value containing at least a portion of said extracted source language GUI component text and a key indicating a location of the localizable method in said bytecode of said software application from which the portion of extracted source language GUI component text was extracted; translating said source language GUI component text of said localization pack file to a target language; in response to said software application executing again, reading said translated GUI component text from said localization pack file; forming a GUI component that includes said translated GUI component text; and displaying said GUI component that includes said translated GUI component text.