convert Primitive Array To Object Array - Java Collection Framework

Description

convert Primitive Array To Object Array

Demo Code

//package com.java2s;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

public class Main {
    public static void main(String[] argv) throws Exception {
        Object value = "java2s.com";
        System.out.println(java.util.Arrays
                .toString(convertPrimitiveArrayToObjectArray(value)));
    }//from   w  w w  .j  av a  2s  .  co m

    public static Object[] convertPrimitiveArrayToObjectArray(Object value) {
        if (value instanceof int[]) {
            return toPrimitiveArray((int[]) value);
        } else if (value instanceof long[]) {
            return toPrimitiveArray((long[]) value);
        } else if (value instanceof short[]) {
            return toPrimitiveArray((short[]) value);
        } else if (value instanceof float[]) {
            return toPrimitiveArray((float[]) value);
        } else if (value instanceof double[]) {
            return toPrimitiveArray((double[]) value);
        } else if (value instanceof char[]) {
            return toPrimitiveArray((char[]) value);
        } else if (value instanceof byte[]) {
            return toPrimitiveArray((byte[]) value);
        } else if (value instanceof boolean[]) {
            return toPrimitiveArray((boolean[]) value);
        } else if (value instanceof Object[]) {
            return (Object[]) value;
        } else {
            throw new RuntimeException("object isn't an array.");
        }
    }

    public static String toString(long[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(int[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(short[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(char[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(byte[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(boolean[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(float[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(double[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();
        buf.append('[');
        buf.append(a[0]);

        for (int i = 1; i < a.length; i++) {
            buf.append(", ");
            buf.append(a[i]);
        }

        buf.append("]");
        return buf.toString();
    }

    public static String toString(Object[] a) {
        if (a == null)
            return "null";
        if (a.length == 0)
            return "[]";

        StringBuffer buf = new StringBuffer();

        for (int i = 0; i < a.length; i++) {
            if (i == 0)
                buf.append('[');
            else
                buf.append(", ");

            buf.append(String.valueOf(a[i]));
        }

        buf.append("]");
        return buf.toString();
    }

    /**
     * <p>
     * Outputs an array as a String, treating <code>null</code> as an empty
     * array.
     * 
     * @param array
     *            the array to get a toString for, may be <code>null</code>
     * @return a String representation of the array, '{}' if null array input
     */
    public static String toString(Object array) {
        if (array == null) {
            return "[]";
        }
        if (array instanceof long[]) {
            return toString((long[]) array);
        }
        if (array instanceof int[]) {
            return toString((int[]) array);
        }
        if (array instanceof short[]) {
            return toString((short[]) array);
        }
        if (array instanceof char[]) {
            return toString((char[]) array);
        }
        if (array instanceof byte[]) {
            return toString((byte[]) array);
        }
        if (array instanceof boolean[]) {
            return toString((boolean[]) array);
        }
        if (array instanceof float[]) {
            return toString((float[]) array);
        }
        if (array instanceof double[]) {
            return toString((double[]) array);
        }
        if (array instanceof Object[]) {
            return toString((Object[]) array);
        }
        return array.toString();
    }

    private static Object[] toPrimitiveArray(char values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Character value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(float values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Float value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(long values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Long value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(short values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Short value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(int values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Integer value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(double values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Double value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(boolean values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Boolean value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    private static Object[] toPrimitiveArray(byte values[]) {
        List<Object> objs = new ArrayList<Object>();
        for (Byte value : values) {
            objs.add(value);
        }
        return objs.toArray();
    }

    public static Object[] toArray(Object... objects) {
        if (objects == null || objects.length == 0) {
            return new Object[0];
        }
        if (objects.length == 1) {
            Object o = objects[0];
            if (o == null) {
                return new Object[] { null };
            } else if (o.getClass().isArray()) {
                return convertPrimitiveArrayToObjectArray(o);
            } else if (o instanceof Collection) {
                Collection coll = (Collection) o;
                Object[] array = new Object[coll.size()];
                int index = 0;
                for (Object item : coll) {
                    array[index++] = item;
                }
                return array;
            } else {
                return new Object[] { o };
            }
        } else {
            Object[] array = new Object[objects.length];
            int index = 0;
            for (Object o : objects) {
                array[index] = o;
                index++;
            }
            return array;
        }
    }

    public static Object[] toArray(Object o1, Object[] o2) {
        if (o2 == null || o2.length == 0) {
            return new Object[] { o1 };
        }
        Object[] arr = new Object[o2.length + 1];
        arr[0] = o1;
        for (int index = 0; index < o2.length; index++) {
            arr[index + 1] = o2[index];
        }
        return arr;
    }

    public static boolean isArray(Object o) {
        if (o instanceof char[]) {// char
            return true;
        } else if (o instanceof boolean[]) {// boolean
            return true;
        } else if (o instanceof byte[]) {// byte
            return true;
        } else if (o instanceof short[]) {// short
            return true;
        } else if (o instanceof int[]) {// int
            return true;
        } else if (o instanceof long[]) {// long
            return true;
        } else if (o instanceof float[]) {// float
            return true;
        } else if (o instanceof double[]) {// double
            return true;
        } else {
            return o instanceof Object[];
        }
    }
}

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