Java Hash Code Calculate hashCode(Object array)

Description

hash Code

License

Open Source License

Declaration

public static int hashCode(Object array) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    public static int hashCode(Object array) {
        if (array == null) {
            return 0;
        } else if (!array.getClass().isArray()) {
            return array.hashCode();
        } else {//  w  w  w.j a  v a  2 s  .  c om
            int hashCode = 17;
            int i;
            if (array instanceof long[]) {
                long[] longArray = (long[]) ((long[]) array);

                for (i = 0; i < longArray.length; ++i) {
                    hashCode = hashCode * 37 + (int) (longArray[i] ^ longArray[i] >> 32);
                }
            } else if (array instanceof int[]) {
                int[] intArray = (int[]) ((int[]) array);

                for (i = 0; i < intArray.length; ++i) {
                    hashCode = hashCode * 37 + intArray[i];
                }
            } else if (array instanceof short[]) {
                short[] shortArray = (short[]) ((short[]) array);

                for (i = 0; i < shortArray.length; ++i) {
                    hashCode = hashCode * 37 + shortArray[i];
                }
            } else if (array instanceof byte[]) {
                byte[] byteArray = (byte[]) ((byte[]) array);

                for (i = 0; i < byteArray.length; ++i) {
                    hashCode = hashCode * 37 + byteArray[i];
                }
            } else if (array instanceof double[]) {
                double[] doubleArray = (double[]) ((double[]) array);

                for (i = 0; i < doubleArray.length; ++i) {
                    long longBits = Double.doubleToLongBits(doubleArray[i]);
                    hashCode = hashCode * 37 + (int) (longBits ^ longBits >> 32);
                }
            } else if (array instanceof float[]) {
                float[] floatArray = (float[]) ((float[]) array);

                for (i = 0; i < floatArray.length; ++i) {
                    hashCode = hashCode * 37 + Float.floatToIntBits(floatArray[i]);
                }
            } else if (array instanceof boolean[]) {
                boolean[] booleanArray = (boolean[]) ((boolean[]) array);

                for (i = 0; i < booleanArray.length; ++i) {
                    hashCode = hashCode * 37 + (booleanArray[i] ? 1 : 0);
                }
            } else if (array instanceof char[]) {
                char[] charArray = (char[]) ((char[]) array);

                for (i = 0; i < charArray.length; ++i) {
                    hashCode = hashCode * 37 + charArray[i];
                }
            } else {
                Object[] objectArray = (Object[]) ((Object[]) array);

                for (i = 0; i < objectArray.length; ++i) {
                    hashCode = hashCode * 37 + hashCode(objectArray[i]);
                }
            }

            return hashCode;
        }
    }
}

Related

1. hashCode(long longVal)
2. hashCode(long value)
3. hashCode(long x)
4. hashCode(long[] a, int fromIndex, int toIndex)
5. hashCode(Object a)
6. hashCode(Object o)
7. hashCode(Object o)
8. hashCode(Object o)
9. hashCode(Object o1, Object o2)