一、十六进制转换工具类
主要包含十六进制字符串转ASCII，ASCII转十六进制字符串以及十六进制字符串转Byte数组等方法：
/**
* Created by wly on 2018/4/17.
*/
public class HexConvert { public static String convertStringToHex(String str){ char[] chars = str.toCharArray(); StringBuffer hex = new StringBuffer();
for(int i = 0; i < chars.length; i++){
hex.append(Integer.toHexString((int)chars[i]));
} return hex.toString();
} public static String convertHexToString(String hex){ StringBuilder sb = new StringBuilder();
StringBuilder sb2 = new StringBuilder(); for( int i=0; i<hex.length()-1; i+=2 ){ String s = hex.substring(i, (i + 2));
int decimal = Integer.parseInt(s, 16);
sb.append((char)decimal);
sb2.append(decimal);
} return sb.toString();
}
public static byte[] hexStringToBytes(String hexString) {
if (hexString == null || hexString.equals("")) {
return null;
}
// toUpperCase将字符串中的所有字符转换为大写
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
// toCharArray将此字符串转换为一个新的字符数组。
char[] hexChars = hexString.toCharArray();
byte[] d = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return d;
}
//返回匹配字符
private static byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
} //将字节数组转换为short类型，即统计字符串长度
public static short bytes2Short2(byte[] b) {
short i = (short) (((b[1] & 0xff) << 8) | b[0] & 0xff);
return i;
}
//将字节数组转换为16进制字符串
public static String BinaryToHexString(byte[] bytes) {
String hexStr = "0123456789ABCDEF";
String result = "";
String hex = "";
for (byte b : bytes) {
hex = String.valueOf(hexStr.charAt((b & 0xF0) >> 4));
hex += String.valueOf(hexStr.charAt(b & 0x0F));
result += hex + " ";
}
return result;
} public static void main(String[] args) { System.out.println("======ASCII码转换为16进制======");
String str = "*00007VERSION\\n1$";
System.out.println("字符串: " + str);
String hex = HexConvert.convertStringToHex(str);
System.out.println("====转换为16进制=====" + hex); System.out.println("======16进制转换为ASCII======");
System.out.println("Hex : " + hex);
System.out.println("ASCII : " + HexConvert.convertHexToString(hex)); byte[] bytes = HexConvert.hexStringToBytes( hex ); System.out.println(HexConvert.BinaryToHexString( bytes ));
}
}
二、接收数据
public class UdpReceiverThread {
public static void main(String[] args) throws Exception {
// 定义一个接收端，并且指定了接收的端口号
DatagramSocket socket = new DatagramSocket(6070);
while (true) {
byte[] buf = new byte[1024*5];
// 解析数据包
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
String ip = packet.getAddress().getHostAddress();
buf = packet.getData();
//将字节数组转换为16进制字符串
String hexString = HexConvert.BinaryToHexString( buf );//含有空格，如：2A 30 30 30 30 37 56 45 52 53 49 4F 4E 5C 6E 31 24
hexString = hexString.replace( " ","" );//去除空格
String asc = HexConvert.convertHexToString( hexString );//转为ASCII,如：*00007VERSION\n1$
System.out.println("收到 " + ip + " 发来的消息：" + asc);
}
}
}三、发送数据
public class UDPSenderThread {
public static void main(String[] args) throws Exception {
DatagramSocket socket = new DatagramSocket();
String serial = "*00007VERSION\\n1$";//串口字符串
String hex = HexConvert.convertStringToHex(serial);//转化为十六进制字符串：2a303030303756455253494f4e5c6e3124
byte[] buf = HexConvert.hexStringToBytes( hex );//将十六进制字符串转为字节数组
//将数据打包
DatagramPacket packet = new DatagramPacket(buf, buf.length, InetAddress.getByName("192.168.11.139"), 6070);
socket.send(packet);
socket.close();
}
}转载自坏菠萝
原文链接：https://blog.csdn.net/abcwanglinyong/article/details/79978061