java 在java中将单个十六进制字符转换为其字节值
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Convert a single hex character to its byte value in java
提问by nos
I have a single hexadecimal character, say
我有一个十六进制字符，说
char c = 'A';
What's the proper way of converting that to its integer value
将其转换为其整数值的正确方法是什么
int value =??;
assert(a == 10);
Doesn't matter really for now if ais an int or a byte.
如果a是整数还是字节，现在并不重要。
回答by Victor
i don't see why you should have to convert to string... in fact this is what parseInt uses:
我不明白为什么你必须转换为字符串......实际上这就是 parseInt 使用的：
public static int digit(char ch, int radix)
public static int digit(char ch, int radix)
int hv = Character.digit(c,16);
if(hv<0)
//do something else because it's not hex then.
回答by nos
Found it myself though.
还是自己找的。
int i = Character.digit('A',16);
回答by jqno
int value;
try {
value = Integer.parseInt(Character.toString(c), 16);
}
catch (NumberFormatException e) {
throw new IllegalArgumentException("Not a hex char");
}
回答by Nat
(byte)Integer.parseInt("a", 16)
(byte)Integer.parseInt("a", 16)
回答by Jon
Take a look at Commons Codec and in particular the Hex class.
看看 Commons Codec，特别是 Hex 类。
http://commons.apache.org/codec/apidocs/org/apache/commons/codec/binary/Hex.html
http://commons.apache.org/codec/apidocs/org/apache/commons/codec/binary/Hex.html
You should be able to convert a hex char array or string to an int value using the toDigit() method:
您应该能够使用 toDigit() 方法将十六进制字符数组或字符串转换为 int 值：
protected static int toDigit(char ch, int index)
You'll need to catch DecoderException though.
不过，您需要捕获 DecoderException。
try {
int i = Hex.toDigit('C');
} catch (DecoderException de) {
log.debug("Decoder exception ", de);
}
There's also methods there to convert a char[] or String to the corresponding byte array as well.
还有一些方法可以将 char[] 或 String 转换为相应的字节数组。
