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package jodd.util;


import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;

/**
 * Some general utilities.
 * All methods are safe as possible and operates with as many types as possible.
 */
public class Util {

    /**
     * Safely compares two objects just like equals() would, except
     * it allows any of the 2 objects to be null.
     *
     * @return true if arguments are equal, otherwise false
     */
    public static boolean equals(Object obj1, Object obj2) {
        return (obj1 != null) ? (obj1.equals(obj2)) : (obj2 == null);
    }


    /**
     * Returns string representation of an object, while checking for null.
     */
    public static String toString(Object value) {
        if (value == null) {
            return null;
        }
        return value.toString();
    }

    // ---------------------------------------------------------------- misc

    /**
     * Returns length of the object. Returns 0 for null.
     * Returns -1 for objects without a length.
     */
    public static int length(Object obj) {
        if (obj == null) {
            return 0;
        }
        if (obj instanceof CharSequence) {
            return ((CharSequence) obj).length();
        }
        if (obj instanceof Collection) {
            return ((Collection) obj).size();
        }
        if (obj instanceof Map) {
            return ((Map) obj).size();
        }

        int count;
        if (obj instanceof Iterator) {
            Iterator iter = (Iterator) obj;
            count = 0;
            while (iter.hasNext()) {
                count++;
                iter.next();
            }
            return count;
        }
        if (obj instanceof Enumeration) {
            Enumeration enumeration = (Enumeration) obj;
            count = 0;
            while (enumeration.hasMoreElements()) {
                count++;
                enumeration.nextElement();
            }
            return count;
        }
        if (obj.getClass().isArray() == true) {
            return Array.getLength(obj);
        }
        return -1;
    }

    /**
     * Returns true if first argument contains provided element.
     * It works for strings, collections, maps and arrays.
     s	 */
    public static boolean containsElement(Object obj, Object element) {
        if (obj == null) {
            return false;
        }
        if (obj instanceof String) {
            if (element == null) {
                return false;
            }
            return ((String) obj).contains(element.toString());
        }
        if (obj instanceof Collection) {
            return ((Collection) obj).contains(element);
        }
        if (obj instanceof Map) {
            return ((Map) obj).values().contains(element);
        }

        if (obj instanceof Iterator) {
            Iterator iter = (Iterator) obj;
            while (iter.hasNext()) {
                Object o = iter.next();
                if (equals(o, element)) {
                    return true;
                }
            }
            return false;
        }
        if (obj instanceof Enumeration) {
            Enumeration enumeration = (Enumeration) obj;
            while (enumeration.hasMoreElements()) {
                Object o = enumeration.nextElement();
                if (equals(o, element)) {
                    return true;
                }
            }
            return false;
        }
        if (obj.getClass().isArray() == true) {
            int len = Array.getLength(obj);
            for (int i = 0; i < len; i++) {
                Object o = Array.get(obj, i);
                if (equals(o, element)) {
                    return true;
                }
            }
        }
        return false;
    }

}