我想在 java Servlet 中解码一个六进制字符串。
String str = "choKKlate+%2F%2F1%3A%D9%81%DB%8C%D9%81%D8%A7%3E2%3A03008498499%2F%2F";
上述 URL 中的以下字符串包含 URL 编码的 unicode Urdu 字符
%D9%81%DB%8C%D9%81%D8%A7
对应于乌尔都语字符串
فیفا
我通过 GET 方法发送 str 字符串变量。在 servlet 中我尝试了 URLDecoder
URLDecoder.decode(str, "UTF-8");
但这会返回问号（'????'）而不是乌尔都语字符。
如何解决这个问题呢？？
这里我不明白的是 % 会在 URL 中扮演一些角色，所以我们不应该在 URL 中传递这个 hexa str 。取而代之的是，您可以使用 base64 算法或用户定义的算法来编码和解码字符串
例如，我们创建一个具有代码的 base 64 类
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;
}
}
现在我们将编写代码来编码和解码字符串
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));
}
}
在这里，我们将 "hello........."+l 作为字符串传递并使用 base64 算法对其进行编码，然后检索它。