java netty 服务端向客户端发送16进制数据，客户端无法接收-已解决
项目中需要通过netty与C语言建立连接，双方是通过16进制进行数据传输
本案例主要介绍如何在JavaNetty与C Sokcet进行字符串通信，Java服务端，C客户端。
重点提示：网络通信中都是byte字节，两边通信一定要统一编码，尽量避免乱码与接收不到的问题。
1.设置ChildChannelInitializer.java中initChannel(SocketChannel ch)
public class ChildChannelInitializer extends ChannelInitializer {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
System.out.println("==================netty报告==================");
System.out.println("信息：有一客户端链接到本服务端");
System.out.println("IP:" + ch.localAddress().getHostName());
System.out.println("Port:" + ch.localAddress().getPort());
System.out.println("==================netty报告完毕==================");
ChannelPipeline pipeline = ch.pipeline();
// 在管道中添加我们自己的接收数据实现方法
/*pipeline.addLast(new MsgEncoder());
pipeline.addLast(new MsgDecoder());*/
//注意 我这里并没有设置管道的编码/解码
pipeline.addLast("handler", serverHandler);
}
...
}
2.在ServerHandler.java中接收C语言客户端发来的16进制字符串
public class ServerHandler extends ChannelHandlerAdapter{
public void channelRead(ChannelHandlerContext channel, Object msg) throws Exception {
try {
ByteBuf buf = (ByteBuf)msg;
byte [] bytes = new byte[buf.readableBytes()];
buf.readBytes(bytes);//复制内容到字节数组bytes
String receiveStr = ConvertCode.receiveHexToString(bytes);//将接收到的数据转为字符串，此字符串就是客户端发送的字符串
//返回16进制到客户端
writeToClient(receiveStr,channel,"测试");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
log.error("异常：",e);
}
}
/**
* 公用回写数据到客户端的方法
* @param 需要回写的字符串
* @param channel
* @param mark 用于打印/log的输出
*
//channel.writeAndFlush(msg);//不行
*
//channel.writeAndFlush(receiveStr.getBytes());//不行
*
在netty里，进出的都是ByteBuf，楼主应确定服务端是否有对应的编码器，将字符串转化为ByteBuf
*/
private void writeToClient(final String receiveStr, ChannelHandlerContext channel, final String mark) {
try {
ByteBuf bufff = Unpooled.buffer();//netty需要用ByteBuf传输
bufff.writeBytes(ConvertCode.hexString2Bytes(receiveStr));//对接需要16进制
channel.writeAndFlush(bufff).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
StringBuilder sb = new StringBuilder("");
if(!StringUtils.isEmpty(mark)){
sb.append("【").append(mark).append("】");
}
if (future.isSuccess()) {
System.out.println(sb.toString()+"回写成功"+receiveStr);
log.info(sb.toString()+"回写成功"+receiveStr);
} else {
System.out.println(sb.toString()+"回写失败"+receiveStr);
log.error(sb.toString()+"回写失败"+receiveStr);
}
}
});
} catch (Exception e) {
e.printStackTrace();
System.out.println("调用通用writeToClient()异常"+e.getMessage());
log.error("调用通用writeToClient()异常：",e);
}
}
...
}
3.编写ConvertCode.java:在第2里面用到了ConvertCode.receiveHexToString(bytes)和ConvertCode.hexString2Bytes(receiveStr)
package com.vk.updoc.netty2;
public class ConvertCode {
/**
* @Title:bytes2HexString
* @Description:字节数组转16进制字符串
* @param b
* 字节数组
* @return 16进制字符串
* @throws
*/
public static String bytes2HexString(byte[] b) {
StringBuffer result = new StringBuffer();
String hex;
for (int i = 0; i < b.length; i++) {
hex = Integer.toHexString(b[i] & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
result.append(hex.toUpperCase());
}
return result.toString();
}
/**
* @Title:hexString2Bytes
* @Description:16进制字符串转字节数组
* @param src 16进制字符串
* @return 字节数组
*/
public static byte[] hexString2Bytes(String src) {
int l = src.length() / 2;
byte[] ret = new byte[l];
for (int i = 0; i < l; i++) {
ret[i] = (byte) Integer
.valueOf(src.substring(i * 2, i * 2 + 2), 16).byteValue();
}
return ret;
}
/**
* @Title:string2HexString
* @Description:字符串转16进制字符串
* @param strPart 字符串
* @return 16进制字符串
*/
public static String string2HexString(String strPart) {
StringBuffer hexString = new StringBuffer();
for (int i = 0; i < strPart.length(); i++) {
int ch = (int) strPart.charAt(i);
String strHex = Integer.toHexString(ch);
hexString.append(strHex);
}
return hexString.toString();
}
/**
* @Title:hexString2String
* @Description:16进制字符串转字符串
* @param src
* 16进制字符串
* @return 字节数组
* @throws
*/
public static String hexString2String(String src) {
String temp = "";
for (int i = 0; i < src.length() / 2; i++) {
//System.out.println(Integer.valueOf(src.substring(i * 2, i * 2 + 2),16).byteValue());
temp = temp+ (char)Integer.valueOf(src.substring(i * 2, i * 2 + 2),16).byteValue();
}
return temp;
}
/**
* @Title:char2Byte
* @Description:字符转成字节数据char-->integer-->byte
* @param src
* @return
* @throws
*/
public static Byte char2Byte(Character src) {
return Integer.valueOf((int)src).byteValue();
}
/**
* @Title:intToHexString
* @Description:10进制数字转成16进制
* @param a 转化数据
* @param len 占用字节数
* @return
* @throws
*/
public static String intToHexString(int a,int len){
len<<=1;
String hexString = Integer.toHexString(a);
int b = len -hexString.length();
if(b>0){
for(int i=0;i1
1 xor f7-->f6
f6 xor 0f-->f9
....
62 xor 84-->e6
即，得到的一字节校验码为：e6
* @return
*/
public static String xor(String strHex_X,String strHex_Y){
//将x、y转成二进制形式
String anotherBinary=Integer.toBinaryString(Integer.valueOf(strHex_X,16));
String thisBinary=Integer.toBinaryString(Integer.valueOf(strHex_Y,16));
String result = "";
//判断是否为8位二进制，否则左补零
if(anotherBinary.length() != 8){
for (int i = anotherBinary.length(); i <8; i++) {
anotherBinary = "0"+anotherBinary;
}
}
if(thisBinary.length() != 8){
for (int i = thisBinary.length(); i <8; i++) {
thisBinary = "0"+thisBinary;
}
}
//异或运算
for(int i=0;i"07dd"
* @param input 需要补位的字符串
* @param size 补位后的最终长度
* @param symbol 按symol补充 如'0'
* @return
* N_TimeCheck中用到了
*/
public static String fill(String input, int size, char symbol) {
while (input.length() < size) {
input = symbol + input;
}
return input;
}
public static void main(String args[]) {
String productNo = "3030303032383838";
System.out.println(hexString2String(productNo));
productNo = "04050103000001070302050304";
System.out.println(hexString2String(productNo));
}
//用Java语言实现对十六进制字符串异或运算http://blog.csdn.net/acrambler/article/details/45743157
}
客户端测试工具我使用的：TCPUDP Socket调试工具 V2.3 绿色免费版