Java 字符串，单个字符到十六进制字节
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Java String, single char to hex bytes
提问by Sarah0050
I want to convert a string by single char to 5 hex bytes and a byte represent a hex number:
我想将单个字符的字符串转换为 5 个十六进制字节，一个字节表示一个十六进制数：
like
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String s = "ABOL1";
to
到
byte[] bytes = {41, 42, 4F, 4C, 01}
I tried following code , but Byte.decodegot error when string is too large, like "4F" or "4C". Is there another way to convert it?
我尝试了以下代码，但是Byte.decode当字符串太大时出错，例如“4F”或“4C”。有没有其他方法可以转换它？
String s = "ABOL1";
char[] array = s.toCharArray();
for (int i = 0; i < array.length; i++) {
String hex = String.format("%02X", (int) array[i]);
bytes[i] = Byte.decode(hex);
}
采纳答案by locoyou
Use String hex = String.format("0x%02X", (int) array[i]);to specify HexDigits with 0xbefore the string.
用于在字符串之前String hex = String.format("0x%02X", (int) array[i]);指定 HexDigits 0x。
A better solution is convert intinto bytedirectly:
更好的解决方案是直接转换int为byte：
bytes[i] = (byte)array[i];
回答by weston
Is there any reason you are trying to go through string? Because you could just do this:
您是否有任何理由尝试通过字符串？因为你可以这样做：
bytes[i] = (byte) array[i];
Or even replace all this code with:
或者甚至将所有这些代码替换为：
byte[] bytes = s.getBytes(StandardCharsets.US_ASCII);
回答by Jordi Castilla
You can convert from charto hex Stringwith String.format():
您可以使用String.format()将其转换char为十六进制：String
String hex = String.format("%04x", (int) array[i]);
Or threat the charas an intand use:
或威胁charas anint并使用：
String hex = Integer.toHexString((int) array[i]);
回答by Klas Lindb?ck
The Byte.decode() javadocspecifies that hex numbers should be on the form "0x4C". So, to get rid of the exception, try this:
该Byte.decode（）的javadoc指定在十六进制数应在表格上"0x4C"。因此，要摆脱异常，请尝试以下操作：
String hex = String.format("0x%02X", (int) array[i]);
There may also be a simpler way to make the conversion, because the String class has a method that converts a string to bytes :
可能还有一种更简单的方法来进行转换，因为 String 类有一个将字符串转换为 bytes 的方法：
bytes = s.getBytes();
Or, if you want a raw conversion to a byte array:
或者，如果您想要原始转换为字节数组：
int i, len = s.length();
byte bytes[] = new byte[len];
String retval = name;
for (i = 0; i < len; i++) {
bytes[i] = (byte) name.charAt(i);
}
