Java实现文件复制常见方式

private static void streamCopyFile(File srcFile, File desFile) {
       try{
          // 使用字节流进行文件复制
          FileInputStream fi = new FileInputStream(srcFile);
          FileOutputStream fo = new FileOutputStream(desFile);
          Integer by = 0;
          //一次读取一个字节
          while((by = fi.read()) != -1) {
              fo.write(by);
          }
          fi.close();
          fo.close();
       }catch(Exception e){
          e.printStackTrace();
       }

 }

private static void bufferedStreamCopyFile(File srcFile, File desFile){
    try{
         // 使用缓冲字节流进行文件复制
         BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));
         BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(desFile));
         byte[] b = new byte[1024];
         Integer len = 0;
         //一次读取1024字节的数据
         while((len = bis.read(b)) != -1) {
             bos.write(b, 0, len);
         }
         bis.close();
         bos.close();
     }catch(Exception e){
          e.printStackTrace();
       }
}

private static void readerWriterCopyFile(File srcFile, File desFile){
    try{
         // 使用字符流进行文件复制，注意：字符流只能复制只含有汉字的文件
          FileReader fr = new FileReader(srcFile);
          FileWriter fw = new FileWriter(desFile);

          Integer by = 0;
          while((by = fr.read()) != -1) {
              fw.write(by);
          }

         fr.close();
         fw.close();
     }catch(Exception e){
          e.printStackTrace();
     }
}

private static void bufferedReaderWriterCopyFile(File srcFile, File desFile){
    try{
         // 使用带缓冲区的高效字符流进行文件复制
          BufferedReader br = new BufferedReader(new FileReader(srcFile));
          BufferedWriter bw = new BufferedWriter(new FileWriter(desFile));

          char[] c = new char[1024];
          Integer len = 0;
          while((len = br.read(c)) != -1) {
              bw.write(c, 0, len);
         }

         //方式二
         /*
         String s = null;
         while((s = br.readLine()) != null) {
             bw.write(s);
             bw.newLine();
         }
        */

         br.close();
         bw.close();
     }catch(Exception e){
          e.printStackTrace();
     }
}

public static void  NIOCopyFile(String  source,String target) {
   try{
       //1.采用RandomAccessFile双向通道完成，rw表示具有读写权限
       RandomAccessFile fromFile = new RandomAccessFile(source,"rw");
       FileChannel fromChannel = fromFile.getChannel();

       RandomAccessFile toFile = new RandomAccessFile(target,"rw");
       FileChannel toChannel = toFile.getChannel();

       long count =  fromChannel.size();
       while (count > 0) {
           long transferred = fromChannel.transferTo(fromChannel.position(), count, toChannel);
           count -= transferred;
        }
       if(fromFile!=null) {
           fromFile.close();
       }
       if(fromChannel!=null) {
           fromChannel.close();
       }
   }catch(Exception e){
        e.printStackTrace();
   }
}

public static void copyFile(String source,String target){
    Path sourcePath = Paths.get(source);
    Path destinationPath = Paths.get(target);
    try {
        Files.copy(sourcePath, destinationPath,
                StandardCopyOption.REPLACE_EXISTING);
    } catch (IOException e) {
        e.printStackTrace();
    }
}