在Java中将字符串转换为十六进制

Question

我试图在java中将像"testing123"这样的字符串转换为十六进制格式.我目前正在使用BlueJ.

要将其转换回来,除了落后之外它是一回事吗？

Answer 1

这是将其转换为十六进制的简短方法:

public String toHex(String arg) {
    return String.format("%040x", new BigInteger(1, arg.getBytes(/*YOUR_CHARSET?*/)));
}

Answer 2

为确保十六进制长度始终为40个字符,BigInteger必须为正数:

public String toHex(String arg) {
  return String.format("%x", new BigInteger(1, arg.getBytes(/*YOUR_CHARSET?*/)));
}

Answer 3

import org.apache.commons.codec.binary.Hex;
...

String hexString = Hex.encodeHexString(myString.getBytes(/* charset */));

http://commons.apache.org/codec/apidocs/org/apache/commons/codec/binary/Hex.html

Answer 4

您编码为十六进制的数字必须代表字符的某些编码,例如UTF-8.因此,首先将String转换为表示该编码中的字符串的byte [],然后将每个字节转换为十六进制.

public static String hexadecimal(String input, String charsetName) throws UnsupportedEncodingException {
    if (input == null) throw new NullPointerException();
    return asHex(input.getBytes(charsetName));
}

private static final char[] HEX_CHARS = "0123456789abcdef".toCharArray();

public static String asHex(byte[] buf)
{
    char[] chars = new char[2 * buf.length];
    for (int i = 0; i < buf.length; ++i)
    {
        chars[2 * i] = HEX_CHARS[(buf[i] & 0xF0) >>> 4];
        chars[2 * i + 1] = HEX_CHARS[buf[i] & 0x0F];
    }
    return new String(chars);
}

Answer 5

Java 17引入了用于十六进制格式化的实用程序类：java.util.HexFormat

转换为十六进制：

public String toHex(String value) {
    return HexFormat.of().formatHex(value.getBytes());
}

从十六进制转换：

public String fromHex(String value) {
    return new String(HexFormat.of().parseHex(value));
}

有关 HexFormat 的更多信息请参见此处

文档：这里

Answer 6

用途DatatypeConverter.printHexBinary():

public static String toHexadecimal(String text) throws UnsupportedEncodingException
{
    byte[] myBytes = text.getBytes("UTF-8");

    return DatatypeConverter.printHexBinary(myBytes);
}

用法示例:

System.out.println(toHexadecimal("Hello StackOverflow"));

打印:

48656C6C6F20537461636B4F766572666C6F77

Answer 7

这是另一种解决方案

public static String toHexString(byte[] ba) {
    StringBuilder str = new StringBuilder();
    for(int i = 0; i < ba.length; i++)
        str.append(String.format("%x", ba[i]));
    return str.toString();
}

public static String fromHexString(String hex) {
    StringBuilder str = new StringBuilder();
    for (int i = 0; i < hex.length(); i+=2) {
        str.append((char) Integer.parseInt(hex.substring(i, i + 2), 16));
    }
    return str.toString();
}

Answer 8

所有基于String.getBytes()的答案都涉及根据Charset对字符串进行编码.您不一定得到构成字符串的2字节字符的十六进制值.如果您真正想要的是十六进制查看器,那么您需要直接访问这些字符.这是我在代码中用于调试Unicode问题的函数:

static String stringToHex(String string) {
  StringBuilder buf = new StringBuilder(200);
  for (char ch: string.toCharArray()) {
    if (buf.length() > 0)
      buf.append(' ');
    buf.append(String.format("%04x", (int) ch));
  }
  return buf.toString();
}

然后,stringToHex("testing123")将为您提供:

0074 0065 0073 0074 0069 006e 0067 0031 0032 0033

Answer 9

我会建议像这样的东西,str输入字符串在哪里:

StringBuffer hex = new StringBuffer();
char[] raw = tokens[0].toCharArray();
for (int i=0;i<raw.length;i++) {
    if     (raw[i]<=0x000F) { hex.append("000"); }
    else if(raw[i]<=0x00FF) { hex.append("00" ); }
    else if(raw[i]<=0x0FFF) { hex.append("0"  ); }
    hex.append(Integer.toHexString(raw[i]).toUpperCase());
}

Answer 10

byte[] bytes = string.getBytes(CHARSET); // you didn't say what charset you wanted
BigInteger bigInt = new BigInteger(bytes);
String hexString = bigInt.toString(16); // 16 is the radix

你可以hexString在这一点上返回,但要注意前导空字符将被剥离,如果第一个字节小于16,结果将有一个奇数长度.如果你需要处理这些情况,你可以添加一些额外的代码用0填充:

StringBuilder sb = new StringBuilder();
while ((sb.length() + hexString.length()) < (2 * bytes.length)) {
  sb.append("0");
}
sb.append(hexString);
return sb.toString();

Answer 11

获取十六进制的Integer值

        //hex like: 0xfff7931e to int
        int hexInt = Long.decode(hexString).intValue();

Answer 12

转换为十六进制代码的字母和十六进制代码的字母。

        String letter = "a";
    String code;
    int decimal;

    code = Integer.toHexString(letter.charAt(0));
    decimal = Integer.parseInt(code, 16);

    System.out.println("Hex code to " + letter + " = " + code);
    System.out.println("Char to " + code + " = " + (char) decimal);