How to convert a hexa String?

Question

I want to decode a hexa string in java Servlet.

String str = "choKKlate+%2F%2F1%3A%D9%81%DB%8C%D9%81%D8%A7%3E2%3A03008498499%2F%2F";

The following string in the above URL contains URL-encoded unicode Urdu characters

%D9%81%DB%8C%D9%81%D8%A7

Which corresponds to Urdu string

فیفا

I am sending the str string variable by GET method. In the servlet I tried URLDecoder

URLDecoder.decode(str, "UTF-8");

But this returns question marks ('????') instead of urdu characters.

How to solve this problem??

The ???? could be a result of trying to print it. Maybe the String itself is correct. — Thilo, Nov 21 '12 at 06:36
Perhaps the font used at this point does not support these characters. How do you output the decoded string? — mdo, Nov 21 '12 at 06:46
String input = request.getParameter("text"); out.println(input); System.out.println(input); — Talha, Nov 21 '12 at 06:49
By HTTP GET method it shows alright in browser but by HTTP POST method it again shows '????' i actually want to use HTTP post method — Talha, Nov 21 '12 at 06:55
ensure your requests have the right encoding (not UTF-8 by default). take a look here: http://stackoverflow.com/questions/138948/how-to-get-utf-8-working-in-java-webapps — Yevgeniy, Nov 21 '12 at 07:23
System.out.println("فیفا"); i simply use this line in java and servlet. java output is fine. but in servlet it display '????'. I think tomcat server do not support unicode language. — Talha, Nov 21 '12 at 08:47

score 0 · Answer 1 · answered Nov 21 '12 at 07:14

here what i undestand is % will pay some role in URL, so we should not pass this hexa str in URL. Instead of this you can use a base64 algorithim or user defined algo to encode and decode the string

for ex we create one base 64 class having code

package com.encrypt;

import java.util.Arrays;

 public class Base64
 {

public Base64()
{
}

public static final char[] encodeToChar(byte abyte0[], boolean flag)
{
    int i = abyte0 == null ? 0 : abyte0.length;
    if(i == 0)
        return new char[0];
    int j = (i / 3) * 3;
    int k = (i - 1) / 3 + 1 << 2;
    int l = k + (flag ? (k - 1) / 76 << 1 : 0);
    char ac[] = new char[l];
    int i1 = 0;
    int j1 = 0;
    int l1 = 0;
    do
    {
        if(i1 >= j)
            break;
        int i2 = (abyte0[i1++] & 0xff) << 16 | (abyte0[i1++] & 0xff) << 8 |     abyte0[i1++] & 0xff;
        ac[j1++] = CA[i2 >>> 18 & 0x3f];
        ac[j1++] = CA[i2 >>> 12 & 0x3f];
        ac[j1++] = CA[i2 >>> 6 & 0x3f];
        ac[j1++] = CA[i2 & 0x3f];
        if(flag && ++l1 == 19 && j1 < l - 2)
                         {
                          ac[j1++] = '\r';
                  ac[j1++] = '\n';
                  l1 = 0;
                 }
             } while(true);
            i1 = i - j;
            if(i1 > 0)
                 {
                  int k1 = (abyte0[j] & 0xff) << 10 | (i1 != 2 ? 0 : (abyte0[i - 1] & 0xff) << 2);
        ac[l - 4] = CA[k1 >> 12];
        ac[l - 3] = CA[k1 >>> 6 & 0x3f];
        ac[l - 2] = i1 != 2 ? '=' : CA[k1 & 0x3f];
        ac[l - 1] = '=';
    }
    return ac;
}

public static final byte[] decode(char ac[])
{
    int i = ac == null ? 0 : ac.length;
    if(i == 0)
        return new byte[0];
    int j = 0;
    for(int k = 0; k < i; k++)
        if(IA[ac[k]] < 0)
            j++;

    if((i - j) % 4 != 0)
        return null;
    int l = 0;
    int i1 = i;
    do
    {
        if(i1 <= 1 || IA[ac[--i1]] > 0)
            break;
        if(ac[i1] == '=')
            l++;
    } while(true);
    i1 = ((i - j) * 6 >> 3) - l;
    byte abyte0[] = new byte[i1];
    int j1 = 0;
    int k1 = 0;
    do
    {
        if(k1 >= i1)
            break;
        int l1 = 0;
        for(int i2 = 0; i2 < 4; i2++)
        {
            int j2 = IA[ac[j1++]];
            if(j2 >= 0)
                l1 |= j2 << 18 - i2 * 6;
            else
                i2--;
        }

        abyte0[k1++] = (byte)(l1 >> 16);
        if(k1 < i1)
        {
            abyte0[k1++] = (byte)(l1 >> 8);
            if(k1 < i1)
                abyte0[k1++] = (byte)l1;
        }
    } while(true);
    return abyte0;
}

public static final byte[] decodeFast(char ac[])
{
    int i = ac.length;
    if(i == 0)
        return new byte[0];
    int j = 0;
    int k;
    for(k = i - 1; j < k && IA[ac[j]] < 0; j++);
    for(; k > 0 && IA[ac[k]] < 0; k--);
    byte byte0 = ac[k] != '=' ? 0 : ((byte)(ac[k - 1] != '=' ? 1 : 2));
    int l = (k - j) + 1;
    int i1 = i <= 76 ? 0 : (ac[76] != '\r' ? 0 : l / 78) << 1;
    int j1 = ((l - i1) * 6 >> 3) - byte0;
    byte abyte0[] = new byte[j1];
    int k1 = 0;
    int l1 = 0;
    int j2 = (j1 / 3) * 3;
    do
    {
        if(k1 >= j2)
            break;
        int i3 = IA[ac[j++]] << 18 | IA[ac[j++]] << 12 | IA[ac[j++]] << 6 | IA[ac[j++]];
        abyte0[k1++] = (byte)(i3 >> 16);
        abyte0[k1++] = (byte)(i3 >> 8);
        abyte0[k1++] = (byte)i3;
        if(i1 > 0 && ++l1 == 19)
        {
            j += 2;
            l1 = 0;
        }
    } while(true);
    if(k1 < j1)
    {
        int i2 = 0;
        for(int k2 = 0; j <= k - byte0; k2++)
            i2 |= IA[ac[j++]] << 18 - k2 * 6;

        for(int l2 = 16; k1 < j1; l2 -= 8)
            abyte0[k1++] = (byte)(i2 >> l2);

    }
    return abyte0;
}

public static final byte[] encodeToByte(byte abyte0[], boolean flag)
{
    int i = abyte0 == null ? 0 : abyte0.length;
    if(i == 0)
        return new byte[0];
    int j = (i / 3) * 3;
    int k = (i - 1) / 3 + 1 << 2;
    int l = k + (flag ? (k - 1) / 76 << 1 : 0);
    byte abyte1[] = new byte[l];
    int i1 = 0;
    int j1 = 0;
    int l1 = 0;
    do
    {
        if(i1 >= j)
            break;
        int i2 = (abyte0[i1++] & 0xff) << 16 | (abyte0[i1++] & 0xff) << 8 | abyte0[i1++] & 0xff;
        abyte1[j1++] = (byte)CA[i2 >>> 18 & 0x3f];
        abyte1[j1++] = (byte)CA[i2 >>> 12 & 0x3f];
        abyte1[j1++] = (byte)CA[i2 >>> 6 & 0x3f];
        abyte1[j1++] = (byte)CA[i2 & 0x3f];
        if(flag && ++l1 == 19 && j1 < l - 2)
        {
            abyte1[j1++] = 13;
            abyte1[j1++] = 10;
            l1 = 0;
        }
    } while(true);
    i1 = i - j;
    if(i1 > 0)
    {
        int k1 = (abyte0[j] & 0xff) << 10 | (i1 != 2 ? 0 : (abyte0[i - 1] & 0xff) << 2);
        abyte1[l - 4] = (byte)CA[k1 >> 12];
        abyte1[l - 3] = (byte)CA[k1 >>> 6 & 0x3f];
        abyte1[l - 2] = i1 != 2 ? 61 : (byte)CA[k1 & 0x3f];
        abyte1[l - 1] = 61;
    }
    return abyte1;
}

public static final byte[] decode(byte abyte0[])
{
    int i = abyte0.length;
    int j = 0;
    for(int k = 0; k < i; k++)
        if(IA[abyte0[k] & 0xff] < 0)
            j++;

    if((i - j) % 4 != 0)
        return null;
    int l = 0;
    int i1 = i;
    do
    {
        if(i1 <= 1 || IA[abyte0[--i1] & 0xff] > 0)
            break;
        if(abyte0[i1] == 61)
            l++;
    } while(true);
    i1 = ((i - j) * 6 >> 3) - l;
    byte abyte1[] = new byte[i1];
    int j1 = 0;
    int k1 = 0;
    do
    {
        if(k1 >= i1)
            break;
        int l1 = 0;
        for(int i2 = 0; i2 < 4; i2++)
        {
            int j2 = IA[abyte0[j1++] & 0xff];
            if(j2 >= 0)
                l1 |= j2 << 18 - i2 * 6;
            else
                i2--;
        }

        abyte1[k1++] = (byte)(l1 >> 16);
        if(k1 < i1)
        {
            abyte1[k1++] = (byte)(l1 >> 8);
            if(k1 < i1)
                abyte1[k1++] = (byte)l1;
        }
    } while(true);
    return abyte1;
}

public static final byte[] decodeFast(byte abyte0[])
{
    int i = abyte0.length;
    if(i == 0)
        return new byte[0];
    int j = 0;
    int k;
    for(k = i - 1; j < k && IA[abyte0[j] & 0xff] < 0; j++);
    for(; k > 0 && IA[abyte0[k] & 0xff] < 0; k--);
    byte byte0 = abyte0[k] != 61 ? 0 : ((byte)(abyte0[k - 1] != 61 ? 1 : 2));
    int l = (k - j) + 1;
    int i1 = i <= 76 ? 0 : (abyte0[76] != 13 ? 0 : l / 78) << 1;
    int j1 = ((l - i1) * 6 >> 3) - byte0;
    byte abyte1[] = new byte[j1];
    int k1 = 0;
    int l1 = 0;
    int j2 = (j1 / 3) * 3;
    do
    {
        if(k1 >= j2)
            break;
        int i3 = IA[abyte0[j++]] << 18 | IA[abyte0[j++]] << 12 | IA[abyte0[j++]] << 6 | IA[abyte0[j++]];
        abyte1[k1++] = (byte)(i3 >> 16);
        abyte1[k1++] = (byte)(i3 >> 8);
        abyte1[k1++] = (byte)i3;
        if(i1 > 0 && ++l1 == 19)
        {
            j += 2;
            l1 = 0;
        }
    } while(true);
    if(k1 < j1)
    {
        int i2 = 0;
        for(int k2 = 0; j <= k - byte0; k2++)
            i2 |= IA[abyte0[j++]] << 18 - k2 * 6;

        for(int l2 = 16; k1 < j1; l2 -= 8)
            abyte1[k1++] = (byte)(i2 >> l2);

    }
    return abyte1;
}

public static final String encodeToString(byte abyte0[], boolean flag)
{
    return new String(encodeToChar(abyte0, flag));
}

public static final byte[] decode(String s)
{
    int i = s == null ? 0 : s.length();
    if(i == 0)
        return new byte[0];
    int j = 0;
    for(int k = 0; k < i; k++)
        if(IA[s.charAt(k)] < 0)
            j++;

    if((i - j) % 4 != 0)
        return null;
    int l = 0;
    int i1 = i;
    do
    {
        if(i1 <= 1 || IA[s.charAt(--i1)] > 0)
            break;
        if(s.charAt(i1) == '=')
            l++;
    } while(true);
    i1 = ((i - j) * 6 >> 3) - l;
    byte abyte0[] = new byte[i1];
    int j1 = 0;
    int k1 = 0;
    do
    {
        if(k1 >= i1)
            break;
        int l1 = 0;
        for(int i2 = 0; i2 < 4; i2++)
        {
            int j2 = IA[s.charAt(j1++)];
            if(j2 >= 0)
                l1 |= j2 << 18 - i2 * 6;
            else
                i2--;
        }

        abyte0[k1++] = (byte)(l1 >> 16);
        if(k1 < i1)
        {
            abyte0[k1++] = (byte)(l1 >> 8);
            if(k1 < i1)
                abyte0[k1++] = (byte)l1;
        }
    } while(true);
    return abyte0;
}

public static final byte[] decodeFast(String s)
{
    int i = s.length();
    if(i == 0)
        return new byte[0];
    int j = 0;
    int k;
    for(k = i - 1; j < k && IA[s.charAt(j) & 0xff] < 0; j++);
    for(; k > 0 && IA[s.charAt(k) & 0xff] < 0; k--);
    byte byte0 = s.charAt(k) != '=' ? 0 : ((byte)(s.charAt(k - 1) != '=' ? 1 : 2));
    int l = (k - j) + 1;
    int i1 = i <= 76 ? 0 : (s.charAt(76) != '\r' ? 0 : l / 78) << 1;
    int j1 = ((l - i1) * 6 >> 3) - byte0;
    byte abyte0[] = new byte[j1];
    int k1 = 0;
    int l1 = 0;
    int j2 = (j1 / 3) * 3;
    do
    {
        if(k1 >= j2)
            break;
        int i3 = IA[s.charAt(j++)] << 18 | IA[s.charAt(j++)] << 12 | IA[s.charAt(j++)] << 6 | IA[s.charAt(j++)];
        abyte0[k1++] = (byte)(i3 >> 16);
        abyte0[k1++] = (byte)(i3 >> 8);
        abyte0[k1++] = (byte)i3;
        if(i1 > 0 && ++l1 == 19)
        {
            j += 2;
            l1 = 0;
        }
    } while(true);
    if(k1 < j1)
    {
        int i2 = 0;
        for(int k2 = 0; j <= k - byte0; k2++)
            i2 |= IA[s.charAt(j++)] << 18 - k2 * 6;

        for(int l2 = 16; k1 < j1; l2 -= 8)
            abyte0[k1++] = (byte)(i2 >> l2);

    }
    return abyte0;
}

private static final char CA[];
private static final int IA[];

static 
{
    CA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
    IA = new int[256];
    Arrays.fill(IA, -1);
    int i = 0;
    for(int j = CA.length; i < j; i++)
        IA[CA[i]] = i;

    IA[61] = 0;
}
 }

now we will write the code to encode and decode the string

package com.encrypt;
import java.util.*;

  public class EnMain {

/**
 * @param args
 */
public static void main(String[] args) {
    // TODO Auto-generated method stub
    long l = (new Date()).getTime();
    System.out.println(" timestamp "+l);
    String userid ="hello------"+l;
    Base64 base = new Base64();
    System.out.println(userid.getBytes());
    String encryptuserid = base.encodeToString(userid.getBytes(), false);
    System.out.println("encrypt values "+encryptuserid);
    byte[] b = base.decode("Y29nbm9zLS0tLS0xMzUxNDMzMjk2Mzk3");
    StringBuffer sb = new StringBuffer();
    for(int i =0;i<b.length;i++){
        byte  bx = b[i];
        System.out.print((char)b[i]);
        sb.append((char)b[i]);
        //String s = ;
    }System.out.println();
    System.out.println(sb);


    String[] as = sb.toString().split("-----");
    long l1 = Long.parseLong(as[1]);
    System.out.println("diff :"+(l1-l));


}

  }

here we passing "hello........."+l as string and encoding it using base64 algo and then retrieving it.

I already tried URLDecoder.decode(str, "UTF-8"); which omits all %. The only problem is hex character decoding... — Talha, Nov 21 '12 at 07:18
what i feel issue is not with hex character. have you tried with some other hex string instead of urdu. it should work. java unicode for urdu is \u0622 and when you decode it, it display ?. — Pri, Nov 21 '12 at 08:10
System.out.println("فیفا"); i simply use this line in java and servlet. java output is fine. but in servlet it display '????'. I think tomcat server do not support unicode language. — Talha, Nov 21 '12 at 08:46

How to convert a hexa String?

1 Answers1