Java Integer Create toInt(byte[] bytes)

Description

Converts a byte array to an int value

License

Apache License

Parameter

Parameter	Description
bytes	byte array

Return

the int value

Declaration

public static int toInt(byte[] bytes) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

public class Main {
    /**/*from  www. j  a  va 2s  .  co m*/
     * Size of int in bytes
     */
    public static final int SIZEOF_INT = Integer.SIZE / Byte.SIZE;

    /**
     * Converts a byte array to an int value
     *
     * @param bytes byte array
     * @return the int value
     */
    public static int toInt(byte[] bytes) {
        return toInt(bytes, 0, SIZEOF_INT);
    }

    /**
     * Converts a byte array to an int value
     *
     * @param bytes  byte array
     * @param offset offset into array
     * @return the int value
     */
    public static int toInt(byte[] bytes, int offset) {
        return toInt(bytes, offset, SIZEOF_INT);
    }

    /**
     * Converts a byte array to an int value
     *
     * @param bytes  byte array
     * @param offset offset into array
     * @param length length of int (has to be {@link #SIZEOF_INT})
     * @return the int value
     * @throws IllegalArgumentException if length is not {@link #SIZEOF_INT} or
     *                                  if there's not enough room in the array at the offset indicated.
     */
    public static int toInt(byte[] bytes, int offset, final int length) {
        if (length != SIZEOF_INT || offset + length > bytes.length) {
            throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_INT);
        }
        int n = 0;
        for (int i = offset; i < (offset + length); i++) {
            n <<= 8;
            n ^= bytes[i] & 0xFF;
        }
        return n;
    }

    private static IllegalArgumentException explainWrongLengthOrOffset(final byte[] bytes, final int offset,
            final int length, final int expectedLength) {
        String reason;
        if (length != expectedLength) {
            reason = "Wrong length: " + length + ", expected " + expectedLength;
        } else {
            reason = "offset (" + offset + ") + length (" + length + ") exceed the" + " capacity of the array: "
                    + bytes.length;
        }
        return new IllegalArgumentException(reason);
    }
}

Related

1. toInt(byte[] bytes)
2. toInt(byte[] bytes)
3. toInt(byte[] bytes)
4. toInt(byte[] bytes)
5. toInt(byte[] bytes)
6. toInt(byte[] bytes)
7. toInt(byte[] bytes)
8. toInt(byte[] bytes)
9. toInt(byte[] bytes)