JAvaファイル名の変更

import java.io.File;

public class RenameFile {
	public static void main(String args[]) {
		File f = new File("/home/tom/test/files");
		if (f.exists()) {
			if (f.isDirectory()) {
				File[] files = f.listFiles();
				for (int i = 0; i < files.length; i++) {
					String oldname = files[i].getName();
					String newname = oldname.substring(0, oldname.length());
					newname = newname + ".zip";
					if (!oldname.equals(newname)) {
						String path = files[i].getParent();
						File newfile = new File(path + "/" + newname);
						if (newfile.exists()) {
							System.out.println(newname + "    ！");
						} else {
							files[i].renameTo(newfile);
						}
					}
				}
			}
		} else {
			System.out.println("File does not exist!");
		}
	}
}