本文梳理一个基础的java TCP消息通信，构造一个简单的Packet进行传输，代码如下：
- Packet
public class Packet {
private String attribute;
public Packet(String attr){
this.attribute = attr;
}
public String getAttribute() {
return attribute;
}
public void setAttribute(String attribute) {
this.attribute = attribute;
}
}- 服务器端代码
public class App {
private static final int PORT = 4000;
public static void main(String[] args) throws IOException {
ServerSocket listen = new ServerSocket(PORT);
Socket client = null;
while(true){
client = listen.accept();
new Thread(new ServerThread(client)).start();
}
}
}public class ServerThread implements Runnable{
private static final int BUFSIZE =1024;
private Socket client = null;
public ServerThread(Socket client){
this.client = client;
}
@Override
public void run() {
try {
InputStream in = client.getInputStream();
OutputStream out = client.getOutputStream();
byte[] buffer = new byte[BUFSIZE];
while (in.read(buffer) != -1) {
//判断包头
if(buffer[0] == 0x01 && buffer[1] == 0x02){
byte[] tmp = new byte[BUFSIZE];
int index = 0;
for(int i = 2; i < buffer.length; i++){
tmp[index++] = buffer[i];
}
Packet packet = new Packet(new String(tmp,"GB2312"));
System.out.println(packet.getAttribute());
}else{
System.out.println("消息格式不正确");
}
}
out.close();
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}- 客户端代码
public class App {
private static final int PORT = 4000;
private static final int BUFSIZE =1024;
public static void main(String[] args) throws IOException {
Socket client = new Socket("127.0.0.1", PORT);
InputStream in = client.getInputStream();
OutputStream out = client.getOutputStream();
Packet packet = new Packet("类型参数2345");
byte[] output = new byte[BUFSIZE];
output[0] = 0x01;
output[1] = 0x02;
int index = 2;
//若增加包长度字段，则可实现packet的分包、组包
byte[] tmp1 = packet.getAttribute().getBytes();
for(int i= 0; i < tmp1.length; i++){
output[index++] = tmp1[i];
}
out.write(output);
byte[] buffer = new byte[BUFSIZE];
while (in.read(buffer) != -1) {
System.out.println(new String(buffer, "GB2312"));
}
out.close();
in.close();
client.close();
}
}