TCP socket通信

TCP Socket 通信

在物联网开发中，通过串口服务器将串口数据转化成网络信号，服务器与终端之间的链接就相应的变成了TCP client 与TCP server链接了，中间传输的数据仍为HEX（十六进制）的指令。

在此 TCP 两部分的实现代码如下（仅做参考）：

1. TCP client

关键代码

/**
 * 发送并接受TCP请求
 *
 * @param IP      远程主机地址
 * @param port    远程主机端口
 * @param reqData 待发送报文的中文字符串形式
 * @return localPort--本地绑定的端口,reqData--请求报文,respData--响应报文,respDataHex--远程主机响应的原始字节的十六进制表示
 */
private static byte[] sendTCPRequest(String IP, String port, String reqData) {
    byte[] resbyte = null;
    OutputStream out = null;      //写
    InputStream in = null;        //读
    Socket socket = new Socket(); //客户机
    try {
        socket.setTcpNoDelay(true);
        socket.setReuseAddress(true);
        socket.setSoTimeout(10000);
        socket.setSoLinger(true, 5);
        socket.setSendBufferSize(1024);
        socket.setReceiveBufferSize(1024);
        socket.setKeepAlive(true);
        socket.connect(new InetSocketAddress(IP, Integer.parseInt(port)), 10000);
        /**
         * 发送HTTP请求
         */
        out = socket.getOutputStream();
        out.write(ByteUtil.hexStringToBytes(reqData));
        /**
         * 接收HTTP响应
         */
        in = socket.getInputStream();
        ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
        byte[] buffer = new byte[256];
        int len = -1;
        while ((len = in.read(buffer)) != -1) {
            bytesOut.write(buffer, 0, len);
            break;
        }
        /**
         * 解码HTTP响应的完整报文
         */
        resbyte = bytesOut.toByteArray();
    } catch (Exception e) {
        System.out.println("与[" + IP + ":" + port + "]通信遇到异常,堆栈信息如下");
        e.printStackTrace();
    } finally {
        if (null != socket && socket.isConnected() && !socket.isClosed()) {
            try {
                socket.close();
            } catch (IOException e) {
                System.out.println("关闭客户机Socket时发生异常,堆栈信息如下");
                e.printStackTrace();
            }
        }
    }
    return resbyte;
}

全代码

import com.jfinal.plugin.activerecord.Db;
import com.jfinal.plugin.activerecord.Record;
import com.utils.ByteUtil;
import com.utils.TimeUtil;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;

/**
 * 使用JavaSocket编写发送TCP请求的工具类
 *
 * @author 玄玉
 * @create Apr 5, 2013 9:25:34 PM
 */
public class TCPUtil {
private TCPUtil() {
}

/**
 * 发送并接受TCP请求
 *
 * @param IP  远程主机地址
 * @param port远程主机端口
 * @param reqData 待发送报文的中文字符串形式
 * @return localPort--本地绑定的端口,reqData--请求报文,respData--响应报文,respDataHex--远程主机响应的原始字节的十六进制表示
 */
private static byte[] sendTCPRequest(String IP, String port, String reqData) {
byte[] resbyte = null;
OutputStream out = null;  //写
InputStream in = null;//读
Socket socket = new Socket(); //客户机
try {
socket.setTcpNoDelay(true);
socket.setReuseAddress(true);
socket.setSoTimeout(10000);
socket.setSoLinger(true, 5);
socket.setSendBufferSize(1024);
socket.setReceiveBufferSize(1024);
socket.setKeepAlive(true);
socket.connect(new InetSocketAddress(IP, Integer.parseInt(port)), 10000);
/**
 * 发送HTTP请求
 */
out = socket.getOutputStream();
out.write(ByteUtil.hexStringToBytes(reqData));
/**
 * 接收HTTP响应
 */
in = socket.getInputStream();
ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
byte[] buffer = new byte[256];
int len = -1;
while ((len = in.read(buffer)) != -1) {
bytesOut.write(buffer, 0, len);
break;
}
/**
 * 解码HTTP响应的完整报文
 */
resbyte = bytesOut.toByteArray();
} catch (Exception e) {
System.out.println("与[" + IP + ":" + port + "]通信遇到异常,堆栈信息如下");
e.printStackTrace();
} finally {
if (null != socket && socket.isConnected() && !socket.isClosed()) {
try {
socket.close();
} catch (IOException e) {
System.out.println("关闭客户机Socket时发生异常,堆栈信息如下");
e.printStackTrace();
}
}
}
return resbyte;
}

/**
 * 发送并获取返回信号
 *
 * @param IP
 * @param port
 * @param reqData
 * @return
 */
public static Record sendAndGetData(String IP, String port, String reqData) {
byte[] res = TCPUtil.sendTCPRequest(IP, port, reqData);
Record item = new Record();
item.set("ip", IP);
item.set("portstr", port);
item.set("send", reqData);
item.set("accept", ByteUtil.toHexString1(res));
item.set("accepttime", TimeUtil.getNowTime());
//保存发送返回记录
Db.save("t_log", item); //保存请求日志
item.set("acceptData", res);
return item;
}

/**
 * @param srcbyte数组
 * @param offset 从数组的第offset位开始
 * @return int数值
 */
public static int bytesToInt(byte[] src, int offset) {
int value;
value = (int) (((src[offset] & 0xFF)<<8)
| ((src[offset + 1] & 0xFF)));
return value;
}

/**
 * byte数组中取int数值，本方法适用于(低位在后，高位在前)的顺序。和intToBytes2（）配套使用
 */
public static int bytesToInt2(byte[] src, int offset) {
int value;
value = (int) ( ((src[offset] & 0xFF)<<24)
|((src[offset+1] & 0xFF)<<16)
|((src[offset+2] & 0xFF)<<8)
|(src[offset+3] & 0xFF));
return value;
}
public static void main(String[] args) {
String reqData = "010300000002C40B";
String IP = "192.168.0.199";
String port = "1030";
}


}

TCP server