Java Utililty Methods Collection Convert

List of utility methods to do Collection Convert

  1. HOME
  2. Java
  3. C
  4. Collection Convert

Description

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

Method

ObjectconvertToIntArray(Collection col)
convert To Int Array 
int[] arr = new int[col.size()];
int pos = 0;
Iterator iter = col.iterator();
while (iter.hasNext()) {
    Number v = (Number) iter.next();
    arr[pos++] = v.intValue();
return arr;
...
T[]convertToPrimitive(Collection info)
convert To Primitive 
return (T[]) info.toArray();
int[][]to2DIntArray(Collection coll)
to D Int Array 
return (int[][]) coll.toArray(new int[coll.size()][]);
String[][]to2DStringArray(Collection coll)
to D String Array 
return (String[][]) coll.toArray(new String[coll.size()][]);
IterabletoAlphaCollection(Collection collection)
to Alpha Collection 
Iterator<U> it = collection.iterator();
List<U> list = new ArrayList<U>();
while (it.hasNext()) {
    list.add(it.next());
Collections.sort(list);
return list;
voidtoArray(Collection items, Object array[], boolean convert_to_primitive)
Put all of the elements in items into the given array This assumes that the array has been pre-allocated 
assert (items.size() == array.length);
int i = 0;
for (T t : items) {
    if (convert_to_primitive) {
        if (t instanceof Long) {
            array[i] = ((Long) t).longValue();
        } else if (t instanceof Integer) {
            array[i] = ((Integer) t).intValue();
...
StringtoCollectionString(Collection c, char sep)
to Collection String 
StringBuilder buf = new StringBuilder();
for (Object obj : c) {
    buf.append(obj).append(sep);
if (buf.length() > 0) {
    buf.setLength(buf.length() - 1);
return buf.toString();
...
StringtoCollectionString(Collection collection_p)
Return a string representation of the given collection which is typically suitable as a match ID representation 
if (collection_p == null)
    return NULL;
StringBuilder builder = new StringBuilder();
builder.append('[');
Iterator<?> it = collection_p.iterator();
while (it.hasNext()) {
    Object element = it.next();
    String segment;
...
StringtoCommaDelimitedString(Collection c)
Returns the elements of c separated by commas. 
return toDelimitedString(c, ", ");
StringtoCommaDelimitedStringInQuotes(Collection c)
Returns the elements of c separated by commas and enclosed in single-quotes 
StringBuffer result = new StringBuffer();
for (Iterator i = c.iterator(); i.hasNext();) {
    Object o = i.next();
    result.append(",'" + o.toString() + "'");
return result.substring(1);