Study Java in application

    It's a long time from my last Java program, for I usually work using C/C++/Objective-C. In this week, I decide to deal with my data from experiment. There are so many data files and it is a depressing work to turn them into a usable format. So I decide to review Java and write some small programs to help me. At first, I try to rename my data files in order to make them simple.

    Data files are in "data" directory with names like "《2006_6》資料.XLS". And I just want them like "2006_6.xls".

　To achieve my point, Regular Expressions and File operations are used. Regular expressions are used for getting new file names from old ones.

 1 import java.io.File;
 2 import java.util.regex.*;
 3 
 4 //Get Old file names
 5 File dir = new File("data");    //"data" are the directory where I store my data files
 6 String[] files = dir.list();
 7 
 8 File old_name = null;
 9 File new_name = null;
10 
11 Pattern pattern = new Pattern.compile("[0-9]+_[0-9]+");
12 
13 for(String file : files)
14 {
15     Matcher matcher = pattern.matcher(file);
16     matcher.find();
17     old_name = new File(dir, file);
18     new_name = new File(dir, matcher.group().concat(".xls"));
19     
20     old_name.renameTo(new_name);
21 }

Now, I can batch renaming my data files for next step.