128进制加密数据示例分享

128进制加密数据，可以自定符号表，使用自己喜欢的符号做加密

package com.wmly.enc;

import java.util.hashmap;

/**
 * 128进制加解密, 一个符号可表示7个bit
 * 可以自定义符号表, 符号不能重复
 */
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 : "这是中国人写地[备思要爱发]编解码程序&拥有独特的自定义符号表|不过布能使用重复字,汗啊(还差一十二个知*.#)。为我们加油吧，亲！".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("符号表长度不正确！");
  }
  for (char a : symboltable) {
   int count = 0;
   for (char b : symboltable) {
    if(a == b) {
     count++;
    }
   }
   if(count > 2) {
    throw new error("符号表有重复符号！");
   }
  }
 }

 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;
 }

 ///////////////////////测试方法///////////////////////////////
 public static void main(string[] args) {
  mybase128 base128 = new mybase128();
  test(base128);

  string txt = "这是我的加解密测试";
  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("加解密失败！: " + r);
   }
  }
 }

 private static string randomdata() {
  string textstring = "了咖啡机累啊戴假发\n\r哦-";
  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);
 }
}