修改文件名

import java.io.File;

public class Test {
    public static void main(String args[]) {
        File f = new File("/Users/houyongkang/Downloads/原名.txt");
        if (f.exists()) {

                    String oldname = f.getName();
                    String newname = newname = "修改后名称.txt";

                    if (!oldname.equals(newname)) {
                        String path = f.getParent();
                        File newfile = new File(path + File.separator + newname);
                        if (newfile.exists()) {
                            System.out.println(newname + "已经存在！");
                        } else {
                            f.renameTo(newfile);
                        }
                    }

        } else {
            System.out.println("File does not exist!");
        }
    }
    }