据我所知，重命名文件不会将其内容附加到具有目标名称的现有文件中。

关于在Java中重命名文件，请参阅file类中renameTo()方法的文档。

简而言之:

Files.move(source, source.resolveSibling("newname"));

更多的细节:

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;

以下内容直接复制自http://docs.oracle.com/javase/7/docs/api/index.html:

假设我们想要重命名一个文件为“newname”，保持文件在相同的目录下:

Path source = Paths.get("path/here");
Files.move(source, source.resolveSibling("newname"));

或者，假设我们想要移动一个文件到新的目录，保持相同的文件名，并替换目录中任何现有的该名称的文件:

Path source = Paths.get("from/path");
Path newdir = Paths.get("to/path");
Files.move(source, newdir.resolve(source.getFileName()), StandardCopyOption.REPLACE_EXISTING);

这是一个简单的重命名文件的方法:

        File oldfile =new File("test.txt");
        File newfile =new File("test1.txt");

        if(oldfile.renameTo(newfile)){
            System.out.println("File renamed");
        }else{
            System.out.println("Sorry! the file can't be renamed");
        }

这是我的代码重命名多个文件在一个文件夹成功:

public static void renameAllFilesInFolder(String folderPath, String newName, String extension) {
    if(newName == null || newName.equals("")) {
        System.out.println("New name cannot be null or empty");
        return;
    }
    if(extension == null || extension.equals("")) {
        System.out.println("Extension cannot be null or empty");
        return;
    }

    File dir = new File(folderPath);

    int i = 1;
    if (dir.isDirectory()) { // make sure it's a directory
        for (final File f : dir.listFiles()) {
            try {
                File newfile = new File(folderPath + "\\" + newName + "_" + i + "." + extension);

                if(f.renameTo(newfile)){
                    System.out.println("Rename succesful: " + newName + "_" + i + "." + extension);
                } else {
                    System.out.println("Rename failed");
                }
                i++;
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

并运行它作为一个例子:

renameAllFilesInFolder("E:\\Downloads\\Foldername", "my_avatar", "gif");

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import static java.nio.file.StandardCopyOption.*;

Path yourFile = Paths.get("path_to_your_file\text.txt");

Files.move(yourFile, yourFile.resolveSibling("text1.txt"));

使用实例替换一个名为“text1.txt”的文件。

Files.move(yourFile, yourFile.resolveSibling("text1.txt"),REPLACE_EXISTING);

是的，您可以使用File.renameTo()。但是，在将其重命名为新文件时，请记住要有正确的路径。

import java.util.Arrays;
import java.util.List;

public class FileRenameUtility {
public static void main(String[] a) {
    System.out.println("FileRenameUtility");
    FileRenameUtility renameUtility = new FileRenameUtility();
    renameUtility.fileRename("c:/Temp");
}

private void fileRename(String folder){
    File file = new File(folder);
    System.out.println("Reading this "+file.toString());
    if(file.isDirectory()){
        File[] files = file.listFiles();
        List<File> filelist = Arrays.asList(files);
        filelist.forEach(f->{
           if(!f.isDirectory() && f.getName().startsWith("Old")){
               System.out.println(f.getAbsolutePath());
               String newName = f.getAbsolutePath().replace("Old","New");
               boolean isRenamed = f.renameTo(new File(newName));
               if(isRenamed)
                   System.out.println(String.format("Renamed this file %s to  %s",f.getName(),newName));
               else
                   System.out.println(String.format("%s file is not renamed to %s",f.getName(),newName));
           }
        });

    }
}

}