Package com.storedobject.common

Class StringList

java.lang.Object

com.storedobject.common.StringList

All Implemented Interfaces:

Iterable<String>, Collection<String>, List<String>, SequencedCollection<String>

public class StringList
extends Object
implements Iterable<String>, List<String>

A class to keep a list of Strings. This class is immutable.

Author:

Syam

Field Summary

Fields

Modifier and Type	Field	Description
protected String[]	array	Internal array to hold the String values.
static final StringList	EMPTY	A constant representing an empty StringList instance.

Method Summary

Modifier and Type	Method	Description
void	add(int index, String element)	Always throws UnsupportedOperationException as StringList is immutable.
boolean	add(String e)	Always throws UnsupportedOperationException as StringList is immutable.
boolean	addAll(int index, Collection<? extends String> c)	Always throws UnsupportedOperationException as StringList is immutable.
boolean	addAll(Collection<? extends String> c)	Always throws UnsupportedOperationException as StringList is immutable.
String[]	array()	Get a copy of the elements as an array.
void	clear()	Always throws UnsupportedOperationException as StringList is immutable.
StringList	concat(StringList another)	Concatenate another list to this list.
static StringList	concat(StringList... lists)	Concatenate an array of lists.
static StringList	concat(StringList first, StringList second)	Concatenate 2 lists..
StringList	concat(String[] another)	Concatenate another list to this list.
static StringList	concat(String[]... lists)	Concatenate an array of lists.
StringList	concat(Collection<String> collection)	Concatenate a collection to this list.
boolean	contains(Object o)	Checks if the list contains the specified element.
boolean	contains(String element)	Check whether this list contains the given element or not.
boolean	contains(String element, int from)	Check whether this list contains the given element or not.
boolean	contains(String element, int from, int to)	Check whether this list contains the given element or not.
boolean	contains(Predicate<String> filter)	Check whether this list contains any element that matches a given predicate or not.
boolean	contains(Predicate<String> filter, int from)	Check whether this list contains any element that matches a given predicate or not.
boolean	contains(Predicate<String> filter, int from, int to)	Check whether this list contains any element that matches a given predicate or not.
boolean	containsAll(Collection<?> c)	Returns true if this list contains all of the elements of the specified collection.
int	copyTo(int startingIndex, int count, String[] buffer)	Copy the elements of this list to a buffer.
int	copyTo(int startingIndex, int count, String[] buffer, int startingBufferIndex)	Copy the elements of this list to a buffer.
int	copyTo(int startingIndex, String[] buffer)	Copy the elements of this list to a buffer.
int	copyTo(int startingIndex, String[] buffer, int startingBufferIndex, int count)	Copy the elements of this list to a buffer.
int	copyTo(String[] buffer)	Copy the elements of this list to a buffer.
int	copyTo(String[] buffer, int startingBufferIndex)	Copy the elements of this list to a buffer.
int	copyTo(String[] buffer, int startingBufferIndex, int count)	Copy the elements of this list to a buffer.
static StringList	create(StringList... list)	Create a string list by concatenating one or more lists.
static StringList	create(Iterable<String> list)	Create a string list from an Iterable.
static StringList	create(String list)	Create a string list.
static StringList	create(String... array)	Create a string list from an array of strings..
static StringList	create(Collection<String> collection)	Create a string list from a collection.
static StringList	create(Iterator<String> list)	Create a string list from an Iterator.
boolean	equals(Object o)	Compares this StringList with another object for equality.
String	get(int index)	Returns the element at the specified position in this list.
int	hashCode()	Returns the hash code for this StringList.
int	indexOf(Object o)	Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
int	indexOf(String element)	Index of an element in the list.
int	indexOf(String element, int from)	Index of an element in the list.
int	indexOf(String element, int from, int to)	Index of an element in the list.
int	indexOf(Predicate<String> filter)	Returns the index of the first occurrence of an element in the list that satisfies the given filter.
int	indexOf(Predicate<String> filter, boolean unique)	Index of an element in the list that matches the given predicate.
int	indexOf(Predicate<String> filter, boolean unique, int from)	Index of an element in the list that matches the given predicate.
int	indexOf(Predicate<String> filter, boolean unique, int from, int to)	Index of an element in the list that matches the given predicate.
int	indexOf(Predicate<String> filter, int from)	Returns the index of the first element that matches the given predicate starting from the specified index.
int	indexOf(Predicate<String> filter, int from, int to)	Index of an element in the list that matches the given predicate.
boolean	isEmpty()	Checks if the list is empty.
Iterator<String>	iterator()	Returns an iterator over the elements in this list in proper sequence.
int	lastIndexOf(Object o)	Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
ListIterator<String>	listIterator()	Always throws UnsupportedOperationException as StringList is immutable.
ListIterator<String>	listIterator(int index)	Always throws UnsupportedOperationException as StringList is immutable.
StringList	map(Function<String,String> converter)	Create another instance by mapping the elements of this list via a converter function.
StringList	minus(StringList another)	Remove elements from this list that are elements of another list.
String	remove(int index)	Always throws UnsupportedOperationException as StringList is immutable.
boolean	remove(Object o)	Always throws UnsupportedOperationException as StringList is immutable.
StringList	remove(String element)	Remove an element from the list.
boolean	removeAll(Collection<?> c)	Always throws UnsupportedOperationException as StringList is immutable.
boolean	retainAll(Collection<?> c)	Always throws UnsupportedOperationException as StringList is immutable.
String	set(int index, String element)	Always throws UnsupportedOperationException as StringList is immutable.
int	size()	Returns the number of elements in this list.
Stream<String>	stream()	Stream the elements.
StringList	subList(int index)	Get a sub-list.
StringList	subList(int start, int end)	Get a sub-list.
Object[]	toArray()	Returns an array containing all of the elements in this list in proper sequence.
<T> T[]	toArray(T[] a)	Always throws UnsupportedOperationException as StringList is immutable.
String	toString()
String	toString(String delimiter)	Concatenate the elements of this list into a String with the given delimiter.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

addFirst, addLast, getFirst, getLast, removeFirst, removeLast, replaceAll, reversed, sort, spliterator

Field Details

EMPTY

public static final StringList EMPTY

A constant representing an empty StringList instance. This is backed by an immutable, empty array and can be used to avoid creating new empty StringList objects unnecessarily. This constant is primarily intended for scenarios where an empty StringList is required, improving readability and reducing memory allocations.

array

protected String[] array

Internal array to hold the String values. This is protected to allow access from subclasses.

Method Details

create

public static StringList create(String list)

Create a string list.

Parameters:

list - Comma delimited list.

Returns:

String list created.

create

public static StringList create(Collection<String> collection)

Create a string list from a collection.

Parameters:

collection - Collection.

Returns:

String list created.

create

public static StringList create(Iterable<String> list)

Create a string list from an Iterable.

Parameters:

list - Iterable.

Returns:

String list created.

create

public static StringList create(Iterator<String> list)

Create a string list from an Iterator.

Parameters:

list - Iterator.

Returns:

String list created.

create

public static StringList create(String... array)

Create a string list from an array of strings..

Parameters:

array - Array of strings.

Returns:

String list created.

create

public static StringList create(StringList... list)

Create a string list by concatenating one or more lists.

Parameters:

list - Lists.

Returns:

String list created.

map

public StringList map(Function<String,String> converter)

Create another instance by mapping the elements of this list via a converter function.

Parameters:

converter - Converter function.

Returns:

Converted list.

equals

public boolean equals(Object o)

Compares this StringList with another object for equality. Two StringLists are considered equal if they contain the same strings in the same order.

Specified by:

equals in interface Collection<String>

Specified by:

equals in interface List<String>

Overrides:

equals in class Object

Parameters:

o - The object to compare with.

Returns:

true if equal, false otherwise.

hashCode

public int hashCode()

Returns the hash code for this StringList.

Specified by:

hashCode in interface Collection<String>

Specified by:

hashCode in interface List<String>

Overrides:

hashCode in class Object

Returns:

Hash code.

add

public void add(int index,
 String element)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

add in interface List<String>

Parameters:

index - Index at which the element is to be inserted.

element - Element to be inserted.

Throws:

UnsupportedOperationException - always.

addAll

public boolean addAll(Collection<? extends String> c)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

addAll in interface Collection<String>

Specified by:

addAll in interface List<String>

Parameters:

c - Collection containing elements to be added.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

add

public boolean add(String e)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

add in interface Collection<String>

Specified by:

add in interface List<String>

Parameters:

e - Element to be added.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

isEmpty

public boolean isEmpty()

Checks if the list is empty.

Specified by:

isEmpty in interface Collection<String>

Specified by:

isEmpty in interface List<String>

Returns:

true if empty, false otherwise.

contains

public boolean contains(Object o)

Checks if the list contains the specified element.

Specified by:

contains in interface Collection<String>

Specified by:

contains in interface List<String>

Parameters:

o - Element to search for.

Returns:

true if found, false otherwise.

toArray

public Object[] toArray()

Returns an array containing all of the elements in this list in proper sequence.

Specified by:

toArray in interface Collection<String>

Specified by:

toArray in interface List<String>

Returns:

An array containing the elements.

toArray

public <T> T[] toArray(T[] a)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

toArray in interface Collection<String>

Specified by:

toArray in interface List<String>

Type Parameters:

T - Type of the array elements.

Parameters:

a - The array into which the elements of the list are to be stored.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

remove

public boolean remove(Object o)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

remove in interface Collection<String>

Specified by:

remove in interface List<String>

Parameters:

o - Element to be removed.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

containsAll

public boolean containsAll(Collection<?> c)

Returns true if this list contains all of the elements of the specified collection.

Specified by:

containsAll in interface Collection<String>

Specified by:

containsAll in interface List<String>

Parameters:

c - Collection to be checked for containment in this list.

Returns:

true if all elements are found, false otherwise.

addAll

public boolean addAll(int index,
 Collection<? extends String> c)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

addAll in interface List<String>

Parameters:

index - Index at which the elements are to be inserted.

c - Collection containing elements to be added.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

removeAll

public boolean removeAll(Collection<?> c)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

removeAll in interface Collection<String>

Specified by:

removeAll in interface List<String>

Parameters:

c - Collection containing elements to be removed.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

retainAll

public boolean retainAll(Collection<?> c)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

retainAll in interface Collection<String>

Specified by:

retainAll in interface List<String>

Parameters:

c - Collection containing elements to be retained.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

clear

public void clear()

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

clear in interface Collection<String>

Specified by:

clear in interface List<String>

Throws:

UnsupportedOperationException - always.

set

public String set(int index,
 String element)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

set in interface List<String>

Parameters:

index - Index of the element to replace.

element - Element to be stored at the specified position.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

remove

public String remove(int index)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

remove in interface List<String>

Parameters:

index - Index of the element to be removed.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

indexOf

public int indexOf(Object o)

Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.

Specified by:

indexOf in interface List<String>

Parameters:

o - Element to search for.

Returns:

Index of the element or -1.

lastIndexOf

public int lastIndexOf(Object o)

Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.

Specified by:

lastIndexOf in interface List<String>

Parameters:

o - Element to search for.

Returns:

Last index of the element or -1.

listIterator

public ListIterator<String> listIterator()

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

listIterator in interface List<String>

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

listIterator

public ListIterator<String> listIterator(int index)

Always throws UnsupportedOperationException as StringList is immutable.

Specified by:

listIterator in interface List<String>

Parameters:

index - Starting index.

Returns:

Never returns.

Throws:

UnsupportedOperationException - always.

get

public String get(int index)

Returns the element at the specified position in this list.

Specified by:

get in interface List<String>

Parameters:

index - Index of the element to return.

Returns:

The element at the specified position.

size

public int size()

Returns the number of elements in this list.

Specified by:

size in interface Collection<String>

Specified by:

size in interface List<String>

Returns:

The number of elements.

array

public String[] array()

Get a copy of the elements as an array.

Returns:

Array containing elements of this list.

indexOf

public int indexOf(String element)

Index of an element in the list.

Parameters:

element - Element.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(String element,
 int from)

Index of an element in the list.

Parameters:

element - Element.

from - Start the search from this position.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(String element,
 int from,
 int to)

Index of an element in the list.

Parameters:

element - Element.

from - Start the search from this position.

to - Stop the search before this position.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(Predicate<String> filter)

Returns the index of the first occurrence of an element in the list that satisfies the given filter.

Parameters:

filter - the predicate used to test elements in the list

Returns:

the index of the first matching element, or -1 if no element satisfies the filter

indexOf

public int indexOf(Predicate<String> filter,
 int from)

Returns the index of the first element that matches the given predicate starting from the specified index.

Parameters:

filter - the predicate used to match elements

from - the index to start the search from (inclusive)

Returns:

the index of the first matching element or -1 if no match is found

indexOf

public int indexOf(Predicate<String> filter,
 int from,
 int to)

Index of an element in the list that matches the given predicate.

Parameters:

filter - Filter predicate.

from - Start the search from this position.

to - Stop the search before this position.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(Predicate<String> filter,
 boolean unique)

Index of an element in the list that matches the given predicate.

Parameters:

filter - Filter predicate.

unique - Whether uniqueness to be checked or not.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(Predicate<String> filter,
 boolean unique,
 int from)

Index of an element in the list that matches the given predicate.

Parameters:

filter - Filter predicate.

unique - Whether uniqueness to be checked or not.

from - Start the search from this position.

Returns:

Index position or -1 if not found.

indexOf

public int indexOf(Predicate<String> filter,
 boolean unique,
 int from,
 int to)

Index of an element in the list that matches the given predicate.

Parameters:

filter - Filter predicate.

unique - Whether uniqueness to be checked or not.

from - Start the search from this position.

to - Stop the search before this position.

Returns:

Index position or -1 if not found.

contains

public boolean contains(String element)

Check whether this list contains the given element or not.

Parameters:

element - Element.

Returns:

True/false.

contains

public boolean contains(String element,
 int from)

Check whether this list contains the given element or not.

Parameters:

element - Element.

from - Start the search from this position.

Returns:

True/false.

contains

public boolean contains(String element,
 int from,
 int to)

Check whether this list contains the given element or not.

Parameters:

element - Element.

from - Start the search from this position.

to - Stop the search before this position.

Returns:

True/false.

contains

public boolean contains(Predicate<String> filter)

Check whether this list contains any element that matches a given predicate or not.

Parameters:

filter - Filter predicate.

Returns:

True/false.

contains

public boolean contains(Predicate<String> filter,
 int from)

Check whether this list contains any element that matches a given predicate or not.

Parameters:

filter - Filter predicate.

from - Start the search from this position.

Returns:

True/false.

contains

public boolean contains(Predicate<String> filter,
 int from,
 int to)

Check whether this list contains any element that matches a given predicate or not.

Parameters:

filter - Filter predicate.

from - Start the search from this position.

to - Stop the search before this position.

Returns:

True/false.

toString

public String toString()

Overrides:

toString in class Object

toString

public String toString(String delimiter)

Concatenate the elements of this list into a String with the given delimiter.

Parameters:

delimiter - Delimiter.

Returns:

Concatenated value.

stream

public Stream<String> stream()

Stream the elements.

Specified by:

stream in interface Collection<String>

Returns:

Stream.

iterator

public Iterator<String> iterator()

Returns an iterator over the elements in this list in proper sequence.

Specified by:

iterator in interface Collection<String>

Specified by:

iterator in interface Iterable<String>

Specified by:

iterator in interface List<String>

Returns:

An iterator.

remove

public StringList remove(String element)

Remove an element from the list.

Parameters:

element - Element to remove.

Returns:

Modified list.

minus

public StringList minus(StringList another)

Remove elements from this list that are elements of another list.

Parameters:

another - Another list.

Returns:

Modified list.

subList

public StringList subList(int index)

Get a sub-list.

Parameters:

index - Index from which sublist to be started.

Returns:

Sub-list.

subList

public StringList subList(int start,
 int end)

Get a sub-list.

Specified by:

subList in interface List<String>

Parameters:

start - Starting index.

end - Ending index (exclusive).

Returns:

Sub-list.

concat

public StringList concat(StringList another)

Concatenate another list to this list.

Parameters:

another - Another list.

Returns:

Concatenated list.

concat

public StringList concat(String[] another)

Concatenate another list to this list.

Parameters:

another - Another list.

Returns:

Concatenated list.

concat

public StringList concat(Collection<String> collection)

Concatenate a collection to this list.

Parameters:

collection - Collection.

Returns:

Concatenated list.

concat

public static StringList concat(StringList first,
 StringList second)

Concatenate 2 lists..

Parameters:

first - First list (could be null).

second - Second list (could be null).

Returns:

Concatenated list.

concat

public static StringList concat(StringList... lists)

Concatenate an array of lists.

Parameters:

lists - Array of lists.

Returns:

Concatenated list.

concat

public static StringList concat(String[]... lists)

Concatenate an array of lists.

Parameters:

lists - Array of lists.

Returns:

Concatenated list.

copyTo

public int copyTo(String[] buffer)

Copy the elements of this list to a buffer.

Parameters:

buffer - Buffer to copy to

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(int startingIndex,
 String[] buffer)

Copy the elements of this list to a buffer.

Parameters:

startingIndex - Starting index of the list from where copy begins

buffer - Buffer to copy to

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(int startingIndex,
 int count,
 String[] buffer)

Copy the elements of this list to a buffer.

Parameters:

startingIndex - Starting index of the list from where copy begins

count - Number of elements to copy

buffer - Buffer to copy to

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(String[] buffer,
 int startingBufferIndex)

Copy the elements of this list to a buffer.

Parameters:

buffer - Buffer to copy to

startingBufferIndex - Starting index of the buffer from where copy begins

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(String[] buffer,
 int startingBufferIndex,
 int count)

Copy the elements of this list to a buffer.

Parameters:

buffer - Buffer to copy to

startingBufferIndex - Starting index of the buffer from where copy begins

count - Number of elements to copy

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(int startingIndex,
 String[] buffer,
 int startingBufferIndex,
 int count)

Copy the elements of this list to a buffer. Same as copyTo(int, int, String[], int).

Parameters:

startingIndex - Starting index of the list from where copy begins

buffer - Buffer to copy to

startingBufferIndex - Starting index of the buffer from where copy begins

count - Number of elements to copy

Returns:

Number of elements copied. Zero will be returned if buffer is null.

copyTo

public int copyTo(int startingIndex,
 int count,
 String[] buffer,
 int startingBufferIndex)

Copy the elements of this list to a buffer.

Parameters:

startingIndex - Starting index of the list from where copy begins

count - Number of elements to copy

buffer - Buffer to copy to

startingBufferIndex - Starting index of the buffer from where copy begins

Returns:

Number of elements copied. Zero will be returned if buffer is null.