Java Utililty Methods Collection to Array

List of utility methods to do Collection to Array

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Description

The list of methods to do Collection to Array are organized into topic(s).

Method

Object[]toArray(T arrayOrCollection)
to Array 
if (arrayOrCollection instanceof Collection) {
    return ((Collection) arrayOrCollection).toArray();
} else {
    return (Object[]) arrayOrCollection;
int[]toArrayInt(Collection integerCollection)
Returns the values of a Integer Collection as array. 
int[] retvals = new int[integerCollection.size()];
int ii = 0;
for (Integer iValue : integerCollection) {
    retvals[ii++] = iValue;
return retvals;
char[][]toArrays(Collection strings)
to Arrays 
char[][] arr = new char[strings.size()][];
int i = 0;
for (String str : strings) {
    arr[i++] = str.toCharArray();
return arr;
String[]toArrayString(Collection col, boolean spacing)
to Array String 
int size = col.size();
if (spacing) {
    size++;
String[] result = new String[size];
int i = 0;
if (spacing) {
    result[i++] = "";
...
CollectiontoBaseTypedCollection(Collection initial)
Workaround for compile time checking of list types. 
return (Collection<T>) initial;
byte[]toByteArray(Collection c)
to Byte Array 
byte arr[] = new byte[c.size()];
int i = 0;
for (Number item : c)
    arr[i++] = item.byteValue();
return arr;
byte[]toByteArray(Collection c)
Converts a Collection of Bytes into a byte[] array. 
int pos = 0;
byte byteArray[] = new byte[c.size()];
for (Byte id : c)
    byteArray[pos++] = id;
return byteArray;
char[]toCharArray(Collection source)
to Char Array 
char[] result = new char[source.size()];
int i = 0;
for (Character c : source)
    result[i++] = c;
return result;
ListtoCharArray(Collection patterns)
to Char Array 
List<char[]> charpatterns = new ArrayList<char[]>(patterns.size());
for (String pattern : patterns) {
    charpatterns.add(pattern.toCharArray());
return charpatterns;
Class[]toClassArray(Collection> collection)
Copy the given Collection into a Class array. 
if (collection == null) {
    return null;
return collection.toArray(new Class<?>[collection.size()]);