网络编程—代码—TCP网络传输

一、TCP：用字符流传输信息

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[用字符流的要点提示]

1:

将套接字关闭之后，字符流自然也就关闭了，所以只需要socket.shutdownOutput();/socket.shutdownInput();

应为套接字开启的字节流封装在字符流Buffered里面，若果先关闭字符流bw.close()，将会关闭套接字。 抛出java.net.SocketException: Socket is closed异常,说明已经将套接字关闭。

2:必须要写入换行符bw.newLine();（或者在内容末尾加 ），这样在用BufferedReader的readerLine() 接收数据包的时候才能读取到一个换行信息，否则会出现读取错误。

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public class Tcpc { // 客户端

 

public static void main(String[] args) throwsUnknownHostException, IOException {

//1.创建套接字指定主机和端口

Socket socket = new Socket(InetAddress.getLocalHost(),8808);

//2打开输入输出流

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

//准备要撒送的数据

String send = "我是客户端，请求登录！";

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(os));

bw.write(send);

bw.newLine();

bw.flush();

socket.shutdownOutput();

 

//4.准备接受返回的信息，并用行读取

BufferedReader br = new BufferedReader(new InputStreamReader(is));

String lin =br.readLine();

System.out.println("客户端开始接受信息！");

while(lin!=null){

System.out.println(lin);

lin=br.readLine();

}

//5关闭资源

socket.shutdownInput();

 

}

}

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public class Tcps { // 服务端

public static void main(String[] args) throws IOException {

//1创建套接字，到指定的端口接受信息

ServerSocket serversocket = new ServerSocket(8808);

//2监听客户端的消息

Socket socket = serversocket.accept();

//3.打开输入输出的流

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

//4封装一个行读取的流

BufferedReader br = new BufferedReader(new InputStreamReader(is));

String lin = br.readLine();

while(lin!=null){

System.out.println(lin);

lin = br.readLine();

}

socket.shutdownInput();

//5给客户端一反馈

String replay="我是服务端，允许登录！";

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(os));

bw.write(replay);

bw.newLine();

bw.flush();

 

//6关闭资源

 

socket.shutdownOutput();

 

}

}

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二、TCP字节流传输信息

 

TCP:字节流传输信息

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public class Tcpc { //客户端

public static void main(String[] args) throwsUnknownHostException, IOException {

//1.创建套接字指定主机和端口

Socket socket = new Socket(InetAddress.getLocalHost(),8808);

//2打开输入输出流

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

//准备要撒送的数据

String send = "我是客户端，请求登录！";

os.write(send.getBytes());

socket.shutdownOutput();

 

//4.准备接受返回的信息，并用行读取

System.out.println("客户端接受完毕！");

byte[] by = new byte[1024];

is.read(by);

System.out.println(new String(by,0,by.length));

//5关闭资源

socket.shutdownInput();

 

}

}

 

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public class Tcps { //服务端

public static void main(String[] args) throws IOException {

//1创建套接字，到指定的端口接受信息

ServerSocket serversocket = new ServerSocket(8808);

//2监听客户端的消息

Socket socket = serversocket.accept();

//3.打开输入输出的流

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

//4封装一个行读取的流

 

System.out.println("服务端接收完毕！");

byte[] by = new byte[1024];

is.read(by);

System.out.println(new String(by,0,by.length));

socket.shutdownInput();

//5给客户端一反馈

String replay="我是服务端，允许登录！";

 

System.out.println("服务端反馈完毕！");

os.write(replay.getBytes());

//6关闭资源

 

socket.shutdownOutput();

 

}

}