将二进制字符串转换为十六进制字符串JAVA

16

我希望将我的二进制字符串转换为十六进制字符串,这只是程序的一部分:

//the variable name of the binary string is: "binary"
int digitNumber = 1;
    int sum = 0;
    int test = binary.length()%4;
    if(test!=0) {
        binary = padLeft(binary, test);
    }
    for(int i = 0; i < binary.length(); i++){
        if(digitNumber == 1)
            sum+=Integer.parseInt(binary.charAt(i) + "")*8;
        else if(digitNumber == 2)
            sum+=Integer.parseInt(binary.charAt(i) + "")*4;
        else if(digitNumber == 3)
            sum+=Integer.parseInt(binary.charAt(i) + "")*2;
        else if(digitNumber == 4 || i < binary.length()+1){
            sum+=Integer.parseInt(binary.charAt(i) + "")*1;
            digitNumber = 0;
            if(sum < 10)
                System.out.print(sum);
            else if(sum == 10)
                System.out.print("A");
            else if(sum == 11)
                System.out.print("B");
            else if(sum == 12)
                System.out.print("C");
            else if(sum == 13)
                System.out.print("D");
            else if(sum == 14)
                System.out.print("E");
            else if(sum == 15)
                System.out.print("F");
            sum=0;
        }
        digitNumber++;  
    }
    public static String padLeft(String s, int n) {
        return String.format("%0$"+n+"s", s);
    }//i added this for padding

问题在于我不知道填充是否有效,但我确信这个程序会返回二进制字符串的错误十六进制转换。我正试图做到这一点:

http://www.wikihow.com/Convert-Binary-to-Hexadecimal

附注:我需要实现它(不能使用任何内置函数)


你看不到任何输出的原因是你的循环条件(i==0)在循环开始时不成立,因此循环从未执行。然而,一旦你解决了这个问题,你的代码还有许多其他错误。 - Don Roby
7个回答

43

如果您不必亲自实现该转换,可以使用现有的代码:

int decimal = Integer.parseInt(binaryStr,2);
String hexStr = Integer.toString(decimal,16);

如果你必须自己实现它,那么你的代码中存在以下几个问题:

  1. 循环应该从0到binary.length()-1迭代(假设字符串的第一个字符表示最高有效位)。
  2. 你默认假设你的二进制字符串有4*x个字符,其中x是整数。如果不是这样,你的算法就会出错。你应该在左侧填充零以获得这种长度的字符串。
  3. sum在输出每个十六进制数字后必须重置为0。
  4. System.out.print(digitNumber); - 在这里你应该输出sum而不是digitNumber

下面是大部分已修复的代码:

    int digitNumber = 1;
    int sum = 0;
    String binary = "011110101010";
    for(int i = 0; i < binary.length(); i++){
        if(digitNumber == 1)
            sum+=Integer.parseInt(binary.charAt(i) + "")*8;
        else if(digitNumber == 2)
            sum+=Integer.parseInt(binary.charAt(i) + "")*4;
        else if(digitNumber == 3)
            sum+=Integer.parseInt(binary.charAt(i) + "")*2;
        else if(digitNumber == 4 || i < binary.length()+1){
            sum+=Integer.parseInt(binary.charAt(i) + "")*1;
            digitNumber = 0;
            if(sum < 10)
                System.out.print(sum);
            else if(sum == 10)
                System.out.print("A");
            else if(sum == 11)
                System.out.print("B");
            else if(sum == 12)
                System.out.print("C");
            else if(sum == 13)
                System.out.print("D");
            else if(sum == 14)
                System.out.print("E");
            else if(sum == 15)
                System.out.print("F");
            sum=0;
        }
        digitNumber++;  
    }

输出:

7AA

仅当二进制位数可被4整除时才有效,因此您必须添加左侧的0填充作为预备步骤。


这是我正在尝试做的事情:http://www.wikihow.com/Convert-Binary-to-Hexadecimal - dumas
@dumas,你差不多做对了,但是你有几个错误,就像我在答案中提到的那样。 - Eran

11

对于任何二进制字符串长度,请使用以下内容:

String hexString = new BigInteger(binaryString, 2).toString(16);

2
BigInteger会删除前导零。如果二进制字符串以“00”开头,则可能会出现问题。 - Zartc

3
你可以尝试像这样做。
private void bitsToHexConversion(String bitStream){

    int byteLength = 4;
    int bitStartPos = 0, bitPos = 0;
    String hexString = "";
    int sum = 0;

    // pad '0' to make input bit stream multiple of 4 

    if(bitStream.length()%4 !=0){
         int tempCnt = 0;
         int tempBit = bitStream.length() % 4;           
         while(tempCnt < (byteLength - tempBit)){
             bitStream = "0" + bitStream;
             tempCnt++;
         }
    }

   // Group 4 bits, and find Hex equivalent 

    while(bitStartPos < bitStream.length()){
        while(bitPos < byteLength){
            sum = (int) (sum + Integer.parseInt("" + bitStream.charAt(bitStream.length()- bitStartPos -1)) * Math.pow(2, bitPos)) ;
            bitPos++;
            bitStartPos++;
        }
        if(sum < 10)
             hexString = Integer.toString(sum) + hexString;
        else 
             hexString = (char) (sum + 55) + hexString;

        bitPos = 0;
        sum = 0;
    }
    System.out.println("Hex String > "+ hexString);
}

希望这可以帮到你 :D

0

/* * 更改许可证头以更改许可证头。 * 要更改模板文件,请选择工具|模板 * 并在编辑器中打开模板。 */ package stringprocessing;

/** * * 作者:Zayeed Chowdhury */ public class StringProcessing {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    // TODO code application logic here
    int index = 0;
    String bin = "0000000101100101011011100110011100000001000000000000000010101010010101100110010101100011011010010110110101100001001000000100111001100101011101000111011101101111011100100110101101110011001000000100100001000001010100110010000001001001010100110101001101010101010001010100010000100000010000010010000001010010010001010101000101010101010010010101001001000101010001000010000001010111010001010100010101001011010011000101100100100000010101000100010101010011010101000010000001000110010011110101001000100000010101000100100001000101001000000100011001001111010011000100110001001111010101110100100101001110010001110010000001000011010011110101010101001110010101000100100101000101010100110010111101000001010100100100010101000001010100110011101000100000010100000110100101101110011000010110110000101100001000000100000101011010001110110010000001000001010101000010000000000001111000000011000100110010001110100011000100110011001000000101000001001101001000000100111101001110";
    String[] hexString = new String[bin.length() / 4];
    for (int i = 0; i < bin.length() / 4; i++) {
        hexString[i] = "";
        for (int j = index; j < index + 4; j++) {
            hexString[i] += bin.charAt(j);
        }
        index += 4;
    }

    for (int i = 0; i < bin.length() / 4; i++) {
        System.out.print(hexString[i] + " ");
    }

    System.out.println("\n" + bin.length());
    String[] result = binaryToHex(hexString);

    for (int i = 0; i < result.length; i++) {
        System.out.print("" + result[i].toUpperCase());
    }
    System.out.println("");
}

public static String[] binaryToHex(String[] bin) {
    String[] result = new String[bin.length];
    for (int i = 0; i < bin.length; i++) {
        result[i] = Integer.toHexString(Integer.parseInt(bin[i], 2));
    }
    //return Integer.toHexString(Integer.parseInt(bin[0], 2));
    return result;
}

}


0
 import java.util.*;
 public class BinaryToHexadecimal
 {
      public static void main()
      {
         Scanner sc=new Scanner(System.in);
         System.out.println("enter the binary number");
         double s=sc.nextDouble();
         int c=0;
         long s1=0;
         String z="";
         while(s>0)
         {
           s1=s1+(long)(Math.pow(2,c)*(long)(s%10));
           s=(long)s/10;
           c++;
         }
         while(s1>0)
         {
           long j=s1%16;
           if(j==10)
           {
              z="A"+z;
           }
           else if(j==11)
           {
              z="B"+z;
           }
           else if(j==12)
           {
              z="C"+z;
           }
           else if(j==13)
           {
              z="D"+z;
           }
           else if(j==14)
           {
              z="E"+z;
           }
           else if(j==15)
           {
              z="F"+z;
           }
           else
           {
              z=j+z;
           }
           s1=s1/16;
      }
    System.out.println("The respective Hexadecimal number is : "+z);
   }
 }

0
通过给定的二进制数01011011,我们首先将其转换为十进制数,每个数字将通过递减长度来计算Math.pow()

01011011 =(0×2(7))+(1×2(6))+(0×2(5))+(1×2(4))+(1×2(3))+(0×2(2))+(1×2(1))+(1×2(0))

=(0×128)+(1×64)+(0×32)+(1×16)+(1×8)+(0×4)+(1×2)+(1×1)

= 0 + 64 + 0 + 16 + 8 + 0 + 2 + 1

= 91(二进制数的十进制形式)

现在获取了十进制数后,我们必须将其转换为十六进制数。
因此,91大于16。所以,我们必须除以16。
除以16后,商为5,余数为11。

余数小于16。

余数的十六进制数为B。

商为5,余数的十六进制数为B。

也就是说,91 = 16 × 5 +11 = B

5 = 16 × 0 + 5 = 5

=5B

实现:

String hexValue = binaryToHex(binaryValue);

    //Display result
    System.out.println(hexValue);


private static String binaryToHex(String binary) {
    int decimalValue = 0;
    int length = binary.length() - 1;
    for (int i = 0; i < binary.length(); i++) {
        decimalValue += Integer.parseInt(binary.charAt(i) + "") * Math.pow(2, length);
        length--;
    }
    return decimalToHex(decimalValue);
}
private static String decimalToHex(int decimal){
    String hex = "";
    while (decimal != 0){
        int hexValue = decimal % 16;
        hex = toHexChar(hexValue) + hex;
        decimal = decimal / 16;
    }
    return hex;
}

private static char toHexChar(int hexValue) {
    if (hexValue <= 9 && hexValue >= 0)
        return (char)(hexValue + '0');
    else
        return (char)(hexValue - 10 + 'A');
}

0

私有最终字符串数组hexValues = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};

public void binaryToHexadecimal(String binary){
    String hexadecimal;
    binary  = leftPad(binary);
    System.out.println(convertBinaryToHexadecimal(binary));

}

public String convertBinaryToHexadecimal(String binary){
    String hexadecimal = "";
    int sum = 0;
    int exp = 0;
    for (int i=0; i<binary.length(); i++){
        exp = 3 - i%4;
        if((i%4)==3){
            sum = sum + Integer.parseInt(binary.charAt(i)+"")*(int)(Math.pow(2,exp));
            hexadecimal = hexadecimal + hexValues[sum];
            sum = 0;
        }
        else
        {
            sum = sum + Integer.parseInt(binary.charAt(i)+"")*(int)(Math.pow(2,exp));
        }
    }
    return hexadecimal;
}

public String leftPad(String binary){
    int paddingCount =  0;
    if ((binary.length()%4)>0)
        paddingCount = 4-binary.length()%4;

    while(paddingCount>0) {
        binary = "0" + binary;
        paddingCount--;
    }
    return binary;
}

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