java 文件读取

File copy

public void fileCopy(String file,String target){
       try(InputStream inputStream = new FileInputStream(file)){
           try(OutputStream outputStream = new FileOutputStream (target)){      
               byte [] buffer = new byte[4096];
               int bytesToRead;
               while((bytesToRead=inputStream.read(buffer))!=-1){
                   outputStream.write(buffer,0,bytesToRead);
               }
           }
       } catch (IOException e) {
        e.printStackTrace();
    }
    }





    public void copyNio(String file,String target){
        try(FileInputStream inputStream = new FileInputStream(file)){
            try(FileOutputStream outputStream = new FileOutputStream(target)){
                FileChannel inChannel = inputStream.getChannel();
                FileChannel oUTChannel = outputStream.getChannel();
                java.nio.ByteBuffer buffer = java.nio.ByteBuffer.allocate(4096);
                while(inChannel.read(buffer)!=-1){
                    buffer.flip();
                    oUTChannel.write(buffer);
                    buffer.clear();
                }
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }