Java批量修改一个目录下的文件名的代码

本来想用Perl的 可惜我还没入门 先用java写个啦 凑合用着先 注意只能用在Win平台 并且所有文件都要有后缀
如果要在Linux那么 "\\" 要改成 "/" 如果文件名没有后缀 自己看着改改咯

import java.io.File;

public class Rename {
    public static void main(String[] args) throws Exception {
        if (args.length == 0 || args[0] == "?" || args[0] == "-?" || args[0] == "/?") {
            printUsage();
            return;
        }
        if (args.length < 2) {
            printUsage();
            return;
        }

        String folderPath = args[0];
        String prefix = args[1];
        String splitter = "_";
        if (args.length > 2) {
            splitter = args[2];
        }

        File folder = new File(folderPath);
        File[] files = folder.listFiles();
        for (int i = 0; i < files.length; i++) {
            File f = files[i];
            String name = f.getCanonicalPath();
            int index1 = name.lastIndexOf("\\");
            int index2 = name.lastIndexOf(".");
            String newName = name.substring(0, index1) + "\\" 
                    + prefix + splitter + i + name.substring(index2);
            f.renameTo(new File(newName));
        }
    }
    
    public static void printUsage()
    {
        System.out.println(
                "usage: java Rename <folderPath> <newFileNamePrefix> <splitter>");
    }
}