128 in-process encrypted data sample sharing _java

128 encryption data, you can customize the symbol table, using their favorite symbols to do encryption

Copy Code code as follows:

Package Com.wmly.enc;

Import Java.util.HashMap;

/**
* 128-plus decryption, a symbol can represent 7 bit
* Can customize the symbol table, the symbol can not repeat
*/
public class MyBASE128 {

public static final char[] symboltable = new char[128];
public static final Hashmap<character, integer> indextable = new hashmap<> (128);
static {
int i = 0;
for (int j = 0; j < 128; J + +) {
SYMBOLTABLE[J] = (char) j;
if (' A ' <= j && J <= ' Z ')
|| ' A ' <= J && J <= ' Z '
|| ' 0 ' <= J && J <= ' 9 ') {
symboltable[i++] = (char) j;
}
}
For char C: "This is written by the Chinese [think about love] codec & have a unique custom symbol table | But the cloth can use repeated words, sweat AH (still 12 to know *.#). Cheer for us, kiss! ". ToCharArray ()) {
symboltable[i++] = c;
}

CheckTable ();

for (int j = 0; j < 128; J + +) {
Indextable.put (Symboltable[j], J);
}
}

 private static void CheckTable () throws Error {
  if (symboltable[127] = = 0) {
    throw New Error ("The symbol table length is not correct!") ");
  }
  for (char a:symboltable) {
   int count = 0;
   for (char b:symboltable) {
    if (a = = b) {
      count++;
    }
   }
   if (Count > 2) {
    throw new Error ("symbol table has duplicate symbol!") ");
   }
  }
 }

Public String encode (byte[] data) {
if (data = null | | data.length = 0) {
return new String ();
}
StringBuilder result = new StringBuilder ();
int tail = 0;
for (int i = 0; i < data.length; i++) {
int mov = (i% 7 + 1);
int curr = 0xFF & Data[i];
int code = tail + (curr >> mov);
Result.append (Symboltable[code]);
Tail = (0xFF & (Curr << (8-mov)) >> 1;
if (mov = 7) {
Result.append (Symboltable[tail]);
tail = 0;
}
}
Result.append (Symboltable[tail]);
return result.tostring ();
}

Public byte[] Decode (String base128) {
if (base128 = null | | base128.length () = 0) {
return new byte[] {};
}
int length = (int) Math.floor (base128.length () * 0.875);
Byte[] result = new Byte[length];
int idx = 0;
int head = indextable.get (Base128.charat (0)) << 1;
for (int i = 1; i < base128.length ();) {
int mod = i% 8;
int code = indextable.get (Base128.charat (i++));
result[idx++] = (byte) (0xFF & Head + (code >> (7-mod)));
if (mod = 7) {
Head = 0xFF & (Indextable.get (Base128.charat (i++)) << 1);
} else {
Head = 0xFF & (code << (mod + 1));
}
}
return result;
}

Test method///////////////////////////////
public static void Main (string[] args) {
MyBASE128 base128 = new MyBASE128 ();
Test (base128);

String txt = "This is my encryption and decryption test";
String enc = Base128.encode (Txt.getbytes ());
SYSTEM.OUT.PRINTLN (ENC);
System.out.println ("----------------");
System.out.println (New String (Base128.decode (ENC)));
}

private static void Test (MyBASE128 base128) {
for (int i = 0; i < 10000; i++) {
String r = Randomdata ();
String d = new String (Base128.decode (Base128.encode (R.getbytes ()));
if (!r.equals (d)) {
D = new String (Base128.decode (Base128.encode (R.getbytes ()));
System.out.println ("Add decryption failed!") : "+ R");
}
}
}

private static String Randomdata () {
String TextString = "The coffee machine tired, wear a wig \n\r oh-";
int start = random (0, Textstring.length ()-3);
int end = Random (start + 1, textstring.length ()-1);
Return textstring.substring (start, end);
}

private static int random (int i, int j) {
return (int) Math.ceil (Math.random () * (j-i) +i);
}
}