Socket(InetAddress address,int port); //创建一个流套接字并将其连接到指定 IP 地址的指定端口号
Socket(String host,int port); //创建一个流套接字并将其连接到指定主机上的指定端口号
Socket(InetAddress address,int port, InetAddress localAddr,int localPort); //创建一个套接字并将其连接到指定远程地址上的指定远程端口
Socket(String host,int port, InetAddress localAddr,int localPort); //创建一个套接字并将其连接到指定远程主机上的指定远程端口
Socket(SocketImpl impl); //使用用户指定的 SocketImpl 创建一个未连接 Socket

public InputStream getInputStream(); //方法获得网络连接输入，同时返回一个IutputStream对象实例
public OutputStream getOutputStream(); //方法连接的另一端将得到输入，同时返回一个OutputStream对象实例
public Socket accept(); //用于产生"阻塞"，直到接受到一个连接，并且返回一个客户端的Socket对象实例。

ServerSocket(int port); //创建绑定到特定端口的服务器套接字
ServerSocket(int port,int backlog); //利用指定的 backlog 创建服务器套接字并将其绑定到指定的本地端口号
ServerSocket(int port,int backlog, InetAddress bindAddr); //使用指定的端口、侦听 backlog 和要绑定到的本地 IP地址创建服务器

    try {
      Socket socket = new Socket("173.1.1.121", 30004);

      //获取控制台输入的内容
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
      System.out.print("请输入发送的字符串：");
      String str = bufferedReader.readLine();

      //给服务端发送消息
      PrintWriter printWriter = new PrintWriter(socket.getOutputStream());
      printWriter.write(str + "\r\n");
      printWriter.flush();

      //关闭资源
      bufferedReader.close();
      printWriter.close();
      socket.close();
    } catch (IOException e) {
      e.printStackTrace();
    }

   InetAddress ia = null;
   try {
     ia = ia.getLocalHost();
     String localname = ia.getHostName();
     String localip = ia.getHostAddress();
     System.out.println("本机名称是：" + localname);
     System.out.println("本机的ip是 ：" + localip);
   } catch (Exception e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
   }

    try {
      mServerSocket = new java.net.ServerSocket(30004);

      Socket socket = mServerSocket.accept();

      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));

      String content = null;
      while ((content=bufferedReader.readLine() )!= null) {
        System.out.println("接收到客服端发来的消息：" +content);
      }

      //关闭连接
      bufferedReader.close();
      socket.close();

    } catch (IOException e) {
      e.printStackTrace();
    }

  //文件名称
  public String fileName;

  //文件长度
  public long fileLength;

  //传输类型
  public int transmissionType;

  //传输内容
  public String content;

  //传输的长度
  public long transLength;

  //发送还是接受类型  1发送 2接收
  public int itemType = 1;

  //0 文本 1 图片
  public int showType;

  /**
   * 文件路径
   *
   * @param filePath
   */
  private void sendFile(String filePath) {
    FileInputStream fis = null;
    File file = new File(filePath);

    try {
      mSendHandler.sendEmptyMessage(Constants.PROGRESS);

      fis = new FileInputStream(file);

      Transmission trans = new Transmission();
      trans.transmissionType = Constants.TRANSFER_FILE;
      trans.fileName = file.getName();
      trans.fileLength = file.length();
      trans.transLength = 0;

      byte[] bytes = new byte[1024];
      int length = 0;
      while ((length = fis.read(bytes, 0, bytes.length)) != -1) {
        trans.transLength += length;
        trans.content = Base64Utils.encode(bytes);
        mPrintWriter.write(mGson.toJson(trans) + "\r\n");
        mPrintWriter.flush();

        //更新进度
        Message message = new Message();
        message.what = Constants.PROGRESS;
        message.obj = 100 * trans.transLength / trans.fileLength;
        mSendHandler.sendMessage(message);
      }
      fis.close();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
      if (fis != null) {
        try {
          fis.close();
        } catch (IOException e1) {
          e1.printStackTrace();
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
      mPrintWriter.close();
    }
  }

    trans.content = Base64Utils.encode(bytes);
    mPrintWriter.write(mGson.toJson(trans) + "\r\n");
    mPrintWriter.flush();

    long fileLength = trans.fileLength;
    long transLength = trans.transLength;
    if (mCreateFile) {
      mCreateFile = false;
      fos = new FileOutputStream(new File("d:/" + trans.fileName));
    }
    byte[] b = Base64Utils.decode(trans.content.getBytes());
    fos.write(b, 0, b.length);
    System.out.println("接收文件进度" + 100 * transLength / fileLength + "%...");
    if (transLength == fileLength) {
      mCreateFile = true;
      fos.flush();
      fos.close();
    }