java 服务器端接受TCP协议,并进行CRC等验证
1.协议消息头结构体struct_msg_header.java
package com.bvcom.SocketThreadDao;
/*** 协议头结构体
* @author zhao
*
*/
public class struct_msg_header {
int sync_byte; // 同步字段=0x00767363
int version_number; // 协议版本号
int public_IP; // 板卡所在的公网IP地址
int card_ID; // 板卡ID
int msg_len; // 消息长度
int msg_CRC; // 消息的CRC值
public int getSync_byte() {
return sync_byte;
}
public void setSync_byte(int sync_byte) {
this.sync_byte = sync_byte;
}
public int getVersion_number() {
return version_number;
}
public void setVersion_number(int version_number) {
this.version_number = version_number;
}
public int getPublic_IP() {
return public_IP;
}
public void setPublic_IP(int public_IP) {
this.public_IP = public_IP;
}
public int getCard_ID() {
return card_ID;
}
public void setCard_ID(int card_ID) {
this.card_ID = card_ID;
}
public int getMsg_len() {
return msg_len;
}
public void setMsg_len(int msg_len) {
this.msg_len = msg_len;
}
public int getMsg_CRC() {
return msg_CRC;
}
public void setMsg_CRC(int msg_CRC) {
this.msg_CRC = msg_CRC;
}
}
2.java服务器端接受tcp协议实例Demo.java
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import com.bvcom.SocketThreadDao.struct_msg_header;
/**
* tcp 服务器端Demo
* @author zhao
*
*/
public class Demo {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
ServerSocket server=null;
try {
server=new ServerSocket(6000);//创建一个ServerSocket在端口6000监听客户请求
} catch (Exception e) {
System.out.println("can not listen to:"+e);//出错，打印出错信息
}
System.out.println("server建立完成");
Socket socket=null;//保存每次客户端请求产生的socket对象
try {
//使用accept()阻塞等待客户请求，有客户
//请求到来则产生一个Socket对象，并继续执行
socket=server.accept();
} catch (Exception e) {
System.out.println("Error."+e);//出错，打印出错信息
}
System.out.println("socket建立完成");
String retString = "";
int num=0;
System.out.println("开始读取循环");
InputStreamReader in=new InputStreamReader(socket.getInputStream(), "UTF-8");
//消息头，（结构体）
byte[] buf = new byte[24];
while(true){
//读取结构体
socket.getInputStream().read( buf );
//结构体实例
struct_msg_header smh=new struct_msg_header();
//bite十六进制数装换为十进制
smh.setSync_byte((buf[3]&0xFF) | ((buf[2]&0xFF) << 8) | ((buf[1]&0xFF) << 16) | ((buf[0]&0xFF) << 24));
smh.setVersion_number((buf[7]&0xFF) | ((buf[6]&0xFF) << 8) | ((buf[5]&0xFF) << 16) | ((buf[4]&0xFF) << 24));
smh.setPublic_IP((buf[11]&0xFF) | ((buf[10]&0xFF) << 8) | ((buf[9]&0xFF) << 16) | ((buf[8]&0xFF) << 24));
smh.setCard_ID((buf[15]&0xFF) | ((buf[14]&0xFF) << 8) | ((buf[13]&0xFF) << 16) | ((buf[12]&0xFF) << 24));
smh.setMsg_len((buf[19]&0xFF) | ((buf[18]&0xFF) << 8) | ((buf[17]&0xFF) << 16) | ((buf[16]&0xFF) << 24));
smh.setMsg_CRC((buf[23]&0xFF) | ((buf[22]&0xFF) << 8) | ((buf[21]&0xFF) << 16) | ((buf[20]&0xFF) << 24));
//双方约定的同步字节
int sync_byte=0x00767363;
//对比收到同步字节和约定的同步字节是否相同
System.out.println("同步字节"+sync_byte+" "+Integer.toHexString(smh.getSync_byte()));
if(smh.getSync_byte()==sync_byte){
System.out.println("setVersion_number"+" "+Integer.toHexString(smh.getVersion_number()));
System.out.println("setPublic_IP"+" "+Integer.toHexString(smh.getPublic_IP()));
System.out.println("setCard_ID"+" "+Integer.toHexString(smh.getCard_ID()));
System.out.println("setMsg_len"+" "+Integer.toHexString(smh.getMsg_len()));
System.out.println("setMsg_CRC"+" "+Integer.toHexString(smh.getMsg_CRC()));
//保存收到的协议主体（长度是协议头下发的Msg_len）
byte[] real_xml = new byte[smh.getMsg_len()];
//从输入流中检索出协议主体
socket.getInputStream().read( real_xml );
//byte数组转换为String
String real_xml_str=new String(real_xml,"UTF-8");
System.out.println("收到的xml协议：" + real_xml_str);
//本地计算协议主体的CRC值
int crc_my=getCRC32(real_xml_str);
System.out.println("my_CRC32:"+crc_my);
//对比消息头下发的CRC和本地计算的CRC是否一致
if(crc_my==smh.getMsg_CRC()){
System.out.println("Contrast CRC is true");
System.out.println("客户端ip："+socket.getInetAddress().toString());
System.out.println("客户端请求验证通过，协议主体："+real_xml_str);
//服务器端通过客户端主动建立的Socket链接回复客户端
//回复协议
String downxml=createReturnXML();
int downXmlLen=downxml.length();
System.out.println("发送协议长度：" + downXmlLen);
//回复消息头的结构体（共六个属性，重置其消息长度属性的值）
for (int i = 0; i < 4; i++) {
System.out.println(Integer.toHexString((downXmlLen >> 8 * i & 0xFF)));
buf[19-i] = (byte) (downXmlLen >> 8 * i & 0xFF);
}
//计算返回协议的CRC
int crc_my_down=getCRC32(downxml);
//回复消息头的结构体（共六个属性，重置其CRC属性的值）
for (int i = 0; i < 4; i++) {
System.out.println(Integer.toHexString((crc_my_down >> 8 * i & 0xFF)));
buf[23-i] = (byte) (crc_my_down >> 8 * i & 0xFF);
}
//回复协议 String 转换为byte数组
byte[] downbyte= downxml.getBytes("utf-8");
int byteLen=buf.length+downbyte.length;
byte[] downbyteSum=new byte[byteLen];
//合并消息头（buf）和消息体（downbyte）byte数组到整体Byte数组downbyteSum
System.arraycopy(buf, 0, downbyteSum, 0, buf.length);
System.arraycopy(downbyte,0, downbyteSum, buf.length, downbyte.length);
//回复发送
socket.getOutputStream().write(downbyteSum);
}else{
System.out.println("Contrast CRC is false");
}
}else{
System.out.println("同步字节不匹配 ");
}
}
} catch (Exception e) {
System.out.println("can not listen to:"+e);//出错，打印出错信息
}
}
/**
* 计算文本CRC的方法
* @param str
* @return
*/
public static int getCRC32(String str){
//参考数组库客户端和服务器端要一致
int[] table = {
0x00000000,0x04c11db7,0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};
//客户端和服务器端的计算方式要一致
byte[] bytes = str.getBytes();
int crc = 0xffffffff;
for (byte b : bytes) {
crc=(crc<<8) ^ table[(int)((crc >> 24) ^ b) & 0xff];
}
return crc;
}
/**
* 回复协议
* @return
*/
public static String createReturnXML(){
StringBuffer strBuff=new StringBuffer();
strBuff.append("");
strBuff.append("
strBuff.append("
strBuff.append("
strBuff.append("
return strBuff.toString();
}
}