You have existing code that contains hardcoded strings.
Use JILT, Eclipse, or your favorite IDE.
Many tools extract Strings into resource bundles. This process is also known as externalization . Nothing to do with jilting your lover, JILT is Sun's Java Internationalization and Localization Toolkit, Version 2.0. JILTing your code means processing it with JILT, which facilitates I18N and L10N'ing the Java classes. JILT has four GUI-based tools, which can be used independently, started from a GUI frontend called JILKIT. Figure 15-1 shows JILT in action.
Figure 15-1. JILT in action
The tools are listed in Table 15-2.
It's worth noting that the time it takes to learn these tools may overshadow their benefits on small projects, but on large projects they will likely prove worthwhile.
Version 2 of the Translator ships with a Chinese dictionary, but you can provide your own dictionaries as well.
The Java Internationalization and Localization Toolkit is nearing its end-of-life support from Sun but can, as of this writing, still be downloaded for free from Sun's Java page, http://java.sun.com/products/jilkit/.
Many IDEs provide an externalization mechanism. Under Eclipse, for example, select a Java source file, then select Externalize Strings from the Source menu. Eclipse generates a Properties file and a class with static methods to retrieve the values of the Strings and replace the strings in your code with calls to those methods. Other IDEs provide similar mechanisms.