ModelUtil (smack 4.0.2 API)

java.lang.Object
- org.jivesoftware.smackx.workgroup.util.ModelUtil

```
public final class ModelUtil
extends Object
```
Utility methods frequently used by data classes and design-time classes.

Method Summary

Methods
Modifier and Type	Method and Description
`static boolean`	`areBooleansDifferent(Boolean b1, Boolean b2)` This is a utility method that compares two Booleans when one or both of the objects might be `null` The result of this method is determined as follows: If `b1` and `b2` are both TRUE or neither `b1` nor `b2` is TRUE, return `false`.
`static boolean`	`areBooleansEqual(Boolean b1, Boolean b2)` This is a utility method that compares two Booleans when one or both of the objects might be `null` The result of this method is determined as follows: If `b1` and `b2` are both TRUE or neither `b1` nor `b2` is TRUE, return `true`.
`static boolean`	`areDifferent(Object o1, Object o2)` This is a utility method that compares two objects when one or both of the objects might be `null`.
`static boolean`	`areEqual(Object o1, Object o2)` This is a utility method that compares two objects when one or both of the objects might be `null` The result of this method is determined as follows: If `o1` and `o2` are the same object according to the `==` operator, return `true`.
`static String`	`concat(String[] strs)` Returns a single string that is the concatenation of all the strings in the specified string array.
`static String`	`concat(String[] strs, String delim)` Returns a single string that is the concatenation of all the strings in the specified string array.
`static String`	`getTimeFromLong(long diff)`
`static boolean`	`hasLength(String s)` Returns `true` if the specified `String` is not `null` and has a length greater than zero.
`static boolean`	`hasNonNullElement(Object[] array)` Returns `true` if the specified array is not null and contains a non-null element.
`static boolean`	`hasStringChanged(String oldString, String newString)` Determines if a string has been changed.
`static <T> List<T>`	`iteratorAsList(Iterator<T> i)` Build a List of all elements in an Iterator.
`static String`	`nullifyIfEmpty(String s)` Returns `null` if the specified string is empty or `null`.
`static String`	`nullifyingToString(Object o)` Returns `null` if the specified object is null or if its `toString()` representation is empty.
`static <T> Iterator<T>`	`reverseListIterator(ListIterator<T> i)` Creates an Iterator that is the reverse of a ListIterator.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - areEqual
```
public static final boolean areEqual(Object o1,
               Object o2)
```
    This is a utility method that compares two objects when one or both of the objects might be null The result of this method is determined as follows:
    1. If o1 and o2 are the same object according to the == operator, return true.
    2. Otherwise, if either o1 or o2 is null, return false.
    3. Otherwise, return o1.equals(o2).
    This method produces the exact logically inverted result as the areDifferent(Object, Object) method.
    
    For array types, one of the equals methods in Arrays should be used instead of this method. Note that arrays with more than one dimension will require some custom code in order to implement equals properly.
  - areBooleansEqual
```
public static final boolean areBooleansEqual(Boolean b1,
                       Boolean b2)
```
    This is a utility method that compares two Booleans when one or both of the objects might be null The result of this method is determined as follows:
    1. If b1 and b2 are both TRUE or neither b1 nor b2 is TRUE, return true.
    2. Otherwise, return false.
  - areDifferent
```
public static final boolean areDifferent(Object o1,
                   Object o2)
```
    This is a utility method that compares two objects when one or both of the objects might be null. The result returned by this method is determined as follows:
    1. If o1 and o2 are the same object according to the == operator, return false.
    2. Otherwise, if either o1 or o2 is null, return true.
    3. Otherwise, return !o1.equals(o2).
    This method produces the exact logically inverted result as the areEqual(Object, Object) method.
    
    For array types, one of the equals methods in Arrays should be used instead of this method. Note that arrays with more than one dimension will require some custom code in order to implement equals properly.
  - areBooleansDifferent
```
public static final boolean areBooleansDifferent(Boolean b1,
                           Boolean b2)
```
    This is a utility method that compares two Booleans when one or both of the objects might be null The result of this method is determined as follows:
    1. If b1 and b2 are both TRUE or neither b1 nor b2 is TRUE, return false.
    2. Otherwise, return true.
    This method produces the exact logically inverted result as the areBooleansEqual(Boolean, Boolean) method.
  - hasNonNullElement
```
public static final boolean hasNonNullElement(Object[] array)
```
    Returns true if the specified array is not null and contains a non-null element. Returns false if the array is null or if all the array elements are null.
  - concat
```
public static final String concat(String[] strs)
```
    Returns a single string that is the concatenation of all the strings in the specified string array. A single space is put between each string array element. Null array elements are skipped. If the array itself is null, the empty string is returned. This method is guaranteed to return a non-null value, if no expections are thrown.
  - concat
```
public static final String concat(String[] strs,
            String delim)
```
    Returns a single string that is the concatenation of all the strings in the specified string array. The strings are separated by the specified delimiter. Null array elements are skipped. If the array itself is null, the empty string is returned. This method is guaranteed to return a non-null value, if no expections are thrown.
  - hasLength
```
public static final boolean hasLength(String s)
```
    Returns true if the specified String is not null and has a length greater than zero. This is a very frequently occurring check.
  - nullifyIfEmpty
```
public static final String nullifyIfEmpty(String s)
```
    Returns null if the specified string is empty or null. Otherwise the string itself is returned.
  - nullifyingToString
```
public static final String nullifyingToString(Object o)
```
    Returns null if the specified object is null or if its toString() representation is empty. Otherwise, the toString() representation of the object itself is returned.
  - hasStringChanged
```
public static boolean hasStringChanged(String oldString,
                       String newString)
```
    Determines if a string has been changed.
    
    Parameters:
    oldString - is the initial value of the String
    newString - is the new value of the String
    
    Returns:
    true If both oldString and newString are null or if they are both not null and equal to each other. Otherwise returns false.
  - getTimeFromLong
```
public static String getTimeFromLong(long diff)
```
  - iteratorAsList
```
public static <T> List<T> iteratorAsList(Iterator<T> i)
```
    Build a List of all elements in an Iterator.
  - reverseListIterator
```
public static <T> Iterator<T> reverseListIterator(ListIterator<T> i)
```
    Creates an Iterator that is the reverse of a ListIterator.

Class ModelUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

areEqual

areBooleansEqual

areDifferent

areBooleansDifferent

hasNonNullElement

concat

concat

hasLength

nullifyIfEmpty

nullifyingToString

hasStringChanged

getTimeFromLong

iteratorAsList

reverseListIterator