Netty-Channel的讀和寫

 

 

 

public class NIOFileChannel01 {

    public static void main(String[] args) throws Exception {
        String str = "hello,帥鍋";
        //創建一個輸出流->channel
        FileOutputStream fileOutputStream = new FileOutputStream("d:\\file01.txt");

        //通過 fileOutputStream 獲取 對應的 FileChannel
        //這個 fileChannel 真實 類型是  FileChannelImpl
        FileChannel fileChannel = fileOutputStream.getChannel();

        //創建一個緩衝區 ByteBuffer
        ByteBuffer byteBuffer = ByteBuffer.allocate(1024);

        //將 str 放入 byteBuffer
        byteBuffer.put(str.getBytes());


        //對byteBuffer 進行flip
        byteBuffer.flip();

        //將byteBuffer 數據寫入到 fileChannel
        fileChannel.write(byteBuffer);
        fileOutputStream.close();
    }
}

 

 

public class NIOFileChannel02 {
    public static void main(String[] args) throws Exception {

        //創建文件的輸入流
        File file = new File("d:\\file01.txt");
        FileInputStream fileInputStream = new FileInputStream(file);

        //通過fileInputStream 獲取對應的FileChannel -> 實際類型  FileChannelImpl
        FileChannel fileChannel = fileInputStream.getChannel();

        //創建緩衝區
        ByteBuffer byteBuffer = ByteBuffer.allocate((int) file.length());

        //將 通道的數據讀入到Buffer
        fileChannel.read(byteBuffer);

        //將byteBuffer 的 字節數據 轉成String
        System.out.println(new String(byteBuffer.array()));
        fileInputStream.close();

    }
}