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    copied!<p>If you just want the unsigned bit sequence as an int.</p> <pre><code>static final int[] lookup = {0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF }; /* * bytes: byte array, with the bits indexed from 0 (MSB) to (bytes.length * 8 - 1) (LSB) * offset: index of the MSB of the bit sequence. * len: length of bit sequence, must from range [0,16]. * Not checked for overflow */ static int getBitSeqAsInt(byte[] bytes, int offset, int len){ int byteIndex = offset / 8; int bitIndex = offset % 8; int val; if ((bitIndex + len) &gt; 16) { val = ((bytes[byteIndex] &lt;&lt; 16 | bytes[byteIndex + 1] &lt;&lt; 8 | bytes[byteIndex + 2]) &gt;&gt; (24 - bitIndex - len)) &amp; lookup[len]; } else if ((offset + len) &gt; 8) { val = ((bytes[byteIndex] &lt;&lt; 8 | bytes[byteIndex + 1]) &gt;&gt; (16 - bitIndex - len)) &amp; lookup[len]; } else { val = (bytes[byteIndex] &gt;&gt; (8 - offset - len)) &amp; lookup[len]; } return val; } </code></pre> <p>If you want it as a String (modification of Margus' answer).</p> <pre><code>static String getBitSequence(byte[] bytes, int offset, int len){ int byteIndex = offset / 8; int bitIndex = offset % 8; int count = 0; StringBuilder result = new StringBuilder(); outer: for(int i = byteIndex; i &lt; bytes.length; ++i) { for(int j = (1 &lt;&lt; (7 - bitIndex)); j &gt; 0; j &gt;&gt;= 1) { if(count == len) { break outer; } if((bytes[byteIndex] &amp; j) == 0) { result.append('0'); } else { result.append('1'); } ++count; } bitIndex = 0; } return result.toString(); } </code></pre>
 

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