Java codeimport java.util.*;
public class Test {
public static void main(String[] args) throws Throwable {
byte[] data = new byte[12]; //测试数据准备，假设LZ所说的串是保存在byte数组中
data[0] = Integer.valueOf("00011101", 2).byteValue(); //头3个数据用LZ的例子数据
data[1] = Integer.valueOf("11000011", 2).byteValue();
data[2] = Integer.valueOf("11000011", 2).byteValue();
for (int i=3; i
data[i] = (i%2 == 0) ? (byte)0x00 : (byte)0xff;
}
System.out.println("test data:"); //测试数据打印
for (int i=0; i
System.out.printf("%s ", bitString((byte)data[i]));
}
System.out.println();
byte key = Integer.valueOf("01110111", 2).byteValue(); //在bit数据中找到的key
System.out.println("key:");
System.out.printf("key=%s\n", bitString(key));
//为了检验程序，程序中对于每次移位以及取数据后做了打印处理
System.out.println("--------test start--------"); //测试开始
byte b = 0;
for (int i=0, bit=0; i
if (i == 0) {
b = data[i]; //第一个数据直接取byte的值
} else {
System.out.printf("before bit offset:b=%s\n", bitString(b));
if (bit > 0) { //如果发生移位，并且不是移动整个byte的时候
b <<= bit; //取下一个byte前bit位来弥补上一个byte不足的数据
b |= (data[i] >> (8-bit)) & (0x00ff >> (8-bit));
System.out.printf("%d bit offset:b=%s\n", bit, bitString(b));
if (b == key) break;
}
for (int j=bit; j<8; j++) { //从下一个数据的bit位开始循环
b <<= 1; //上次数据左移1位
b |= ((data[i] >> (8-j-1)) & 1); //用下一个数据的1位来补到上次数据的后1位
System.out.printf("1 bit offset:b=%s\n", bitString(b));
if (b == key) { //如果找到key，则退出循环，并保存移动的bit数
bit = (j+1)%8;
break;
}
if (j == 7 && bit > 0) bit = 0;
}
}
if (b == key) { //如果找到key
System.out.printf("find key=%s\n", bitString(b));
char[] c = new char[4]; //取64位信息保存到字符数组中
for (int j=i, k=0, cnt=0; j
if (j==i) {
b = data[j]; //第一个byte数据直接保存
} else {
if (bit > 0) { //如果发生了移位，即不是整byte的时候
b <<= bit; //上一个byte左移bit位
b |= (data[j] >> (8-bit)) & (0x00ff >> (8-bit)); //用下一个的前bit位补到上一个数据的后bit位
}
if (cnt == 0) { //第一个byte的时候
c[k] = (char)b; //保存到字符数组中，并让字符左移8位，相当于字符的高8位保存
c[k] <<= 8;
cnt++;
} else if (cnt == 1) { //第二个byte的时候，保存字符的低8位
c[k] |= b;
k++;
cnt = 0;
}
b = data[j];
}
}
for (int j=0; j
System.out.printf("char data = %s\n", bitString(c[j]));
}
i += 8;
if (i < data.length) b = data[i];
}
}
System.out.println("--------test end--------");
}
public static String bitString(byte b) { //获取byte的二进制信息
StringBuilder buf = new StringBuilder(Integer.toBinaryString(b & 0x000000ff));
while (buf.length() < 8) {
buf.insert(0, "0");
}
return buf.toString();
}
public static String bitString(char c) {//获取char的二进制信息
StringBuilder buf = new StringBuilder(Integer.toBinaryString(c & 0x0000ffff));
while (buf.length() < 16) {
buf.insert(0, "0");
}
return buf.toString();
}
}
/*
简单测试了一下，结果如下
test data:
00011101 11000011 11000011 11111111 00000000 11111111 00000000 11111111 00000000
11111111 00000000 11111111
key:
key=01110111
--------test start--------
before bit offset:b=00011101
1 bit offset:b=00111011
1 bit offset:b=01110111
find key=01110111
char data = 0000111100001111
char data = 1111110000000011
char data = 1111110000000011
char data = 1111110000000011
before bit offset:b=11111111
2 bit offset:b=11111100
1 bit offset:b=11111000
1 bit offset:b=11110000
1 bit offset:b=11100000
1 bit offset:b=11000000
1 bit offset:b=10000000
1 bit offset:b=00000000
before bit offset:b=00000000
1 bit offset:b=00000001
1 bit offset:b=00000011
1 bit offset:b=00000111
1 bit offset:b=00001111
1 bit offset:b=00011111
1 bit offset:b=00111111
1 bit offset:b=01111111
1 bit offset:b=11111111
--------test end--------
*/