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POByte Array to *Signed* Int
 

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    <p>I'm trying to convert <code>-101</code> to a byte array and then convert the byte array back to <code>-101</code>. My methods below work for positive values but not for negative values. Can you suggest what I'm doing wrong? Instead of <code>-101</code>, the <code>byteArrayToInt</code> method returns <code>65435</code>. Thanks!</p> <pre><code>/** * Converts a &lt;code&gt;byte&lt;/code&gt; array to a 32-bit &lt;code&gt;int&lt;/code&gt;. * * @param array The &lt;code&gt;byte&lt;/code&gt; array to convert. * @return The 32-bit &lt;code&gt;int&lt;/code&gt; value. */ public static int byteArrayToInt(byte[] array) { ValidationUtils.checkNull(array); int value = 0; for (int i = 0; i &lt; array.length; i++) { int shift = (array.length - 1 - i) * 8; value = value | (array[i] &amp; 0xFF) &lt;&lt; shift; } return value; } /** * Converts a 32-bit &lt;code&gt;int&lt;/code&gt; to a &lt;code&gt;byte&lt;/code&gt; array. * * @param value The 32-bit &lt;code&gt;int&lt;/code&gt; to convert. * @return The &lt;code&gt;byte&lt;/code&gt; array. */ public static byte[] intToByteArray(int value, int size) { byte[] bytes = new byte[size]; for (int index = 0; index &lt; bytes.length; index++) { bytes[index] = (byte) (value &gt;&gt;&gt; (8 * (size - index - 1))); } return bytes; } /** * Tests the utility methods in this class. * * @param args None. */ public static void main(String... args) { System.out.println(byteArrayToInt(intToByteArray(32, 2)) == 32); // true System.out.println(byteArrayToInt(intToByteArray(64, 4)) == 64); // true System.out.println(byteArrayToInt(intToByteArray(-101, 2)) == -101); // false System.out.println(byteArrayToInt(intToByteArray(-101, 4)) == -101); // true } </code></pre>
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