java - 通过删除 Java 中的前导零来缩短十六进制数

Question

我在字符串中有可用的十六进制数字，我想通过删除前导零来缩短它。我需要用 Java 来做

例如:

0000000000000000000000000A000000   -> 0x0A000000
0x0000000000000000000000000A000000 -> 0x0A000000

000000000000000000000000C0A80000   -> 0xC0A80000
0x000000000000000000000000C0A80000 -> 0xC0A80000

当前下面的代码抛出 NumberFormatException 异常

System.out.println(Long.toHexString(Long.parseLong("0x0000000000000000000000000A000000")));

Answer 1

正如其他人提到的，十六进制字符串不以 0x 开头，这只是 hexadecimal literals 的前缀。 .

实现您想要的目标的一种可能性如下:

void foo(String myString) {
    /*
        Here we're making myString upper case and checking if it begins w/ 0x.
        If the string starts with 0X, that'll be replaced with an empty string.
    */
    if ((myString = myString.ToUpperCase()).startsWith("0X")) {
        myString = myString.replace("0X", "");
    }

    String parsedHex = Long.toHexString(Long.parseLong(myString, 16 /* This is the radix (base) of the number. In this case we want hex (16) */));
    System.out.println(String.format("0x%s%s", parsedHex.length() % 2 == 0 ? "" : "0" /* If it's an odd number, add a leading zero. */, parsedHex));

}