#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
#region Imports
using System;
using System.Collections;
using System.Reflection;
#endregion
namespace Spring.Util{
/// <summary>
/// Miscellaneous collection utility methods.
/// </summary>
/// <remarks>
/// Mainly for internal use within the framework.
/// </remarks>
/// <author>Mark Pollack (.NET)</author>
public sealed class CollectionUtils
{
/// <summary>
/// Checks if the given array or collection has elements and none of the elements is null.
/// </summary>
/// <param name="collection">the collection to be checked.</param>
/// <returns>true if the collection has a length and contains only non-null elements.</returns>
public static bool HasElements(ICollection collection)
{
return ArrayUtils.HasElements(collection);
}
/// <summary>
/// Checks if the given array or collection is null or has no elements.
/// </summary>
/// <param name="collection"></param>
/// <returns></returns>
public static bool HasLength(ICollection collection)
{
return ArrayUtils.HasLength(collection);
}
/// <summary>
/// Determine whether a given collection only contains
/// a single unique object
/// </summary>
/// <param name="coll"></param>
/// <returns></returns>
public static bool HasUniqueObject(ICollection coll)
{
if (coll.Count == 0)
{
return false;
}
object candidate = null;
foreach (object elem in coll)
{
if (candidate == null)
{
candidate = elem;
}
else if (candidate != elem)
{
return false;
}
}
return true;
}
/// <summary>
/// Determines whether the <paramref name="collection"/> contains the specified <paramref name="element"/>.
/// </summary>
/// <param name="collection">The collection to check.</param>
/// <param name="element">The object to locate in the collection.</param>
/// <returns><see lang="true"/> if the element is in the collection, <see lang="false"/> otherwise.</returns>
public static bool Contains(IEnumerable collection, Object element)
{
if (collection == null)
{
return false;
}
if (collection is IList)
{
return ((IList) collection).Contains(element);
}
if (collection is IDictionary)
{
return ((IDictionary) collection).Contains(element);
}
MethodInfo method = collection.GetType().GetMethod("contains", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (null != method)
{
return (bool)method.Invoke(collection, new Object[] { element });
}
foreach (object item in collection)
{
if (object.Equals(item, element))
{
return true;
}
}
return false;
}
/// <summary>
/// Adds the specified <paramref name="element"/> to the specified <paramref name="collection"/> .
/// </summary>
/// <param name="collection">The collection to add the element to.</param>
/// <param name="element">The object to add to the collection.</param>
public static void Add(ICollection collection, object element)
{
Add((IEnumerable)collection, element);
}
/// <summary>
/// Adds the specified <paramref name="element"/> to the specified <paramref name="enumerable"/> .
/// </summary>
/// <param name="enumerable">The enumerable to add the element to.</param>
/// <param name="element">The object to add to the collection.</param>
public static void Add(IEnumerable enumerable, object element)
{
if (enumerable == null)
{
throw new ArgumentNullException("enumerable", "Collection cannot be null.");
}
if (enumerable is IList)
{
((IList)enumerable).Add(element);
return;
}
MethodInfo method;
method = enumerable.GetType().GetMethod("add", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (null == method)
{
throw new InvalidOperationException("Enumerable type " + enumerable.GetType() + " does not implement a Add() method.");
}
method.Invoke(enumerable, new Object[] { element });
}
/// <summary>
/// Determines whether the collection contains all the elements in the specified collection.
/// </summary>
/// <param name="targetCollection">The collection to check.</param>
/// <param name="sourceCollection">Collection whose elements would be checked for containment.</param>
/// <returns>true if the target collection contains all the elements of the specified collection.</returns>
public static bool ContainsAll(ICollection targetCollection, ICollection sourceCollection)
{
if (targetCollection == null)
{
throw new ArgumentNullException("targetCollection", "Collection cannot be null.");
}
if (sourceCollection == null)
{
throw new ArgumentNullException("sourceCollection", "Collection cannot be null.");
}
if (sourceCollection.Count == 0 && targetCollection.Count > 1)
return true;
IEnumerator sourceCollectionEnumerator = sourceCollection.GetEnumerator();
bool contains = false;
MethodInfo method;
method = targetCollection.GetType().GetMethod("containsAll", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (method != null)
contains = (bool)method.Invoke(targetCollection, new Object[] { sourceCollection });
else
{
method = targetCollection.GetType().GetMethod("Contains", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (method == null)
{
throw new InvalidOperationException("Target collection does not implment a Contains() or ContainsAll() method.");
}
while (sourceCollectionEnumerator.MoveNext() == true)
{
if ((contains = (bool)method.Invoke(targetCollection, new Object[] { sourceCollectionEnumerator.Current })) == false)
break;
}
}
return contains;
}
/// <summary>
/// Removes all the elements from the target collection that are contained in the source collection.
/// </summary>
/// <param name="targetCollection">Collection where the elements will be removed.</param>
/// <param name="sourceCollection">Elements to remove from the target collection.</param>
public static void RemoveAll(ICollection targetCollection, ICollection sourceCollection)
{
if (targetCollection == null || sourceCollection == null)
{
throw new ArgumentNullException("Collection cannot be null.");
}
ArrayList al = ToArrayList(sourceCollection);
MethodInfo method;
method = targetCollection.GetType().GetMethod("removeAll", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (method != null)
method.Invoke(targetCollection, new Object[] { al });
else
{
method = targetCollection.GetType().GetMethod("Remove", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public, null, new Type[1] { typeof(object) }, null);
MethodInfo methodContains = targetCollection.GetType().GetMethod("Contains", BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public);
if (method == null)
{
throw new InvalidOperationException("Target Collection must implement either a RemoveAll() or Remove() method.");
}
if (methodContains == null)
{
throw new InvalidOperationException("TargetCollection must implement a Contains() method.");
}
IEnumerator e = al.GetEnumerator();
while (e.MoveNext() == true)
{
while ((bool)methodContains.Invoke(targetCollection, new Object[] { e.Current }) == true)
method.Invoke(targetCollection, new Object[] { e.Current });
}
}
}
/// <summary>
/// Converts an <see cref="System.Collections.ICollection"/>instance to an <see cref="System.Collections.ArrayList"/> instance.
/// </summary>
/// <param name="inputCollection">The <see cref="System.Collections.ICollection"/> instance to be converted.</param>
/// <returns>An <see cref="System.Collections.ArrayList"/> instance in which its elements are the elements of the <see cref="System.Collections.ICollection"/> instance.</returns>
/// <exception cref="System.ArgumentNullException">if the <paramref name="inputCollection"/> is null.</exception>
public static ArrayList ToArrayList(ICollection inputCollection)
{
if (inputCollection == null)
{
throw new ArgumentNullException("Collection cannot be null.");
}
return new ArrayList(inputCollection);
}
/// <summary>
/// Copies the elements of the <see cref="ICollection"/> to a
/// new array of the specified element type.
/// </summary>
/// <param name="inputCollection">The <see cref="System.Collections.ICollection"/> instance to be converted.</param>
/// <param name="elementType">The element <see cref="Type"/> of the destination array to create and copy elements to</param>
/// <returns>An array of the specified element type containing copies of the elements of the <see cref="ICollection"/>.</returns>
public static Array ToArray(ICollection inputCollection, Type elementType)
{
Array array = Array.CreateInstance(elementType, inputCollection.Count);
inputCollection.CopyTo(array, 0);
return array;
}
/// <summary>
/// Returns the first element contained in both, <paramref name="source"/> and <paramref name="candidates"/>.
/// </summary>
/// <remarks>The implementation assumes that <paramref name="candidates"/> <<< <paramref name="source"/></remarks>
/// <param name="source">the source enumerable. may be <c>null</c></param>
/// <param name="candidates">the list of candidates to match against <paramref name="source"/> elements. may be <c>null</c></param>
/// <returns>the first element found in both enumerables or <c>null</c></returns>
public static object FindFirstMatch(IEnumerable source, IEnumerable candidates)
{
if (IsEmpty(source) || IsEmpty(candidates))
{
return null;
}
IList candidateList = candidates as IList;
if (candidateList == null)
{
if (candidates is ICollection)
{
candidateList = new ArrayList((ICollection)candidates);
}
else
{
candidateList = new ArrayList();
foreach (object el in candidates)
{
candidateList.Add(el);
}
}
}
foreach (object sourceElement in source)
{
if (candidateList.Contains(sourceElement))
{
return sourceElement;
}
}
return null;
}
/// <summary>
/// Finds a value of the given type in the given collection.
/// </summary>
/// <param name="collection">The collection to search.</param>
/// <param name="type">The type to look for.</param>
/// <returns>a value of the given type found, or null if none.</returns>
/// <exception cref="ArgumentException">If more than one value of the given type is found</exception>
public static object FindValueOfType(ICollection collection, Type type)
{
if (IsEmpty(collection))
{
return null;
}
Type typeToUse = (type != null ? type : typeof(object));
object val = null;
foreach (object obj in collection)
{
if (typeToUse.IsAssignableFrom(obj.GetType()))
{
if (val != null)
{
throw new ArgumentException("More than one value of type[" + typeToUse.Name + "] found.");
}
val = obj;
}
}
return val;
}
/// <summary>
/// Finds a value of the given type in the given collection.
/// </summary>
/// <param name="collection">The collection to search.</param>
/// <param name="type">The type to look for.</param>
/// <returns>a collection of matching values of the given type found, empty if none found, or null if the input collection was null.</returns>
public static ICollection FindValuesOfType(IEnumerable collection, Type type)
{
if (IsEmpty(collection))
{
return null;
}
Type typeToUse = (type != null ? type : typeof(object));
ArrayList results = new ArrayList();
foreach (object obj in collection)
{
if (typeToUse.IsAssignableFrom(obj.GetType()))
{
results.Add(obj);
}
}
return results;
}
/// <summary>
/// Find a value of one of the given types in the given Collection,
/// searching the Collection for a value of the first type, then
/// searching for a value of the second type, etc.
/// </summary>
/// <param name="collection">The collection to search.</param>
/// <param name="types">The types to look for, in prioritized order.</param>
/// <returns>a value of the given types found, or <code>null</code> if none</returns>
/// <exception cref="ArgumentException">If more than one value of the given type is found</exception>
public static object FindValueOfType(ICollection collection, Type[] types)
{
if (IsEmpty(collection) || ObjectUtils.IsEmpty(types))
{
return null;
}
foreach (Type type in types)
{
object val = FindValueOfType(collection, type);
if (val != null)
{
return val;
}
}
return null;
}
/// <summary>
/// Determines whether the specified collection is null or empty.
/// </summary>
/// <param name="enumerable">The collection to check.</param>
/// <returns>
/// <c>true</c> if the specified collection is empty or null; otherwise, <c>false</c>.
/// </returns>
public static bool IsEmpty(IEnumerable enumerable)
{
if (enumerable == null)
return true;
if (enumerable is ICollection)
{
return (0 == ((ICollection)enumerable).Count);
}
IEnumerator it = enumerable.GetEnumerator();
if (!it.MoveNext())
{
return true;
}
return false;
}
/// <summary>
/// Determines whether the specified collection is null or empty.
/// </summary>
/// <param name="collection">The collection to check.</param>
/// <returns>
/// <c>true</c> if the specified collection is empty or null; otherwise, <c>false</c>.
/// </returns>
public static bool IsEmpty(ICollection collection)
{
return (collection == null || collection.Count == 0);
}
/// <summary>
/// Determines whether the specified dictionary is null empty.
/// </summary>
/// <param name="dictionary">The dictionary to check.</param>
/// <returns>
/// <c>true</c> if the specified dictionary is empty or null; otherwise, <c>false</c>.
/// </returns>
public static bool IsEmpty(IDictionary dictionary)
{
return (dictionary == null || dictionary.Count == 0);
}
/// <summary>
/// A callback method used for comparing to items.
/// </summary>
/// <remarks>
/// </remarks>
/// <param name="left">the first object to compare</param>
/// <param name="right">the second object to compare</param>
/// <returns>Value Condition Less than zero x is less than y. Zero x equals y. Greater than zero x is greater than y.</returns>
/// <seealso cref="IComparer.Compare"/>
/// <seealso cref="CollectionUtils.StableSort(IEnumerable,CompareCallback)"/>
public delegate int CompareCallback(object left, object right);
/// <summary>
/// A simple stable sorting routine - far from being efficient, only for small collections.
/// </summary>
/// <param name="input"></param>
/// <param name="comparer"></param>
/// <returns></returns>
public static ICollection StableSort(IEnumerable input, IComparer comparer)
{
return StableSort(input, new CompareCallback(comparer.Compare));
}
/// <summary>
/// A simple stable sorting routine - far from being efficient, only for small collections.
/// </summary>
/// <remarks>
/// Sorting is not(!) done in-place. Instead a sorted copy of the original input is returned.
/// </remarks>
/// <param name="input">input collection of items to sort</param>
/// <param name="comparer">the <see cref="CompareCallback"/> for comparing 2 items in <paramref name="input"/>.</param>
/// <returns>a new collection of stable sorted items.</returns>
public static ICollection StableSort(IEnumerable input, CompareCallback comparer)
{
ArrayList ehancedInput = new ArrayList();
IEnumerator it = input.GetEnumerator();
int index = 0;
while (it.MoveNext())
{
ehancedInput.Add(new Entry(index, it.Current));
index++;
}
ehancedInput.Sort(Entry.GetComparer(comparer));
for (int i = 0; i < ehancedInput.Count; i++)
{
ehancedInput[i] = ((Entry)ehancedInput[i]).Value;
}
return ehancedInput;
}
/// <summary>
/// A simple stable sorting routine - far from being efficient, only for small collections.
/// </summary>
/// <remarks>
/// Sorting is not(!) done in-place. Instead a sorted copy of the original input is returned.
/// </remarks>
/// <param name="input">input collection of items to sort</param>
/// <param name="comparer">the <see cref="IComparer"/> for comparing 2 items in <paramref name="input"/>.</param>
/// <returns>a new collection of stable sorted items.</returns>
public static void StableSortInPlace(IList input, IComparer comparer)
{
StableSortInPlace(input, new CompareCallback(comparer.Compare));
}
/// <summary>
/// A simple stable sorting routine - far from being efficient, only for small collections.
/// </summary>
/// <remarks>
/// Sorting is not(!) done in-place. Instead a sorted copy of the original input is returned.
/// </remarks>
/// <param name="input">input collection of items to sort</param>
/// <param name="comparer">the <see cref="CompareCallback"/> for comparing 2 items in <paramref name="input"/>.</param>
/// <returns>a new collection of stable sorted items.</returns>
public static void StableSortInPlace(IList input, CompareCallback comparer)
{
ArrayList ehancedInput = new ArrayList();
IEnumerator it = input.GetEnumerator();
int index = 0;
while (it.MoveNext())
{
ehancedInput.Add(new Entry(index, it.Current));
index++;
}
ehancedInput.Sort(Entry.GetComparer(comparer));
for (int i = 0; i < ehancedInput.Count; i++)
{
input[i] = ((Entry)ehancedInput[i]).Value;
}
}
#region StableSort Utility Classes
private class Entry
{
private class EntryComparer : IComparer
{
private readonly CompareCallback innerComparer;
public EntryComparer(CompareCallback innerComparer)
{
this.innerComparer = innerComparer;
}
public int Compare(object x, object y)
{
Entry ex = (Entry)x;
Entry ey = (Entry)y;
int result = innerComparer(ex.Value, ey.Value);
if (result == 0)
{
result = ex.Index.CompareTo(ey.Index);
}
return result;
}
}
public static IComparer GetComparer(CompareCallback innerComparer)
{
return new EntryComparer(innerComparer);
}
public readonly int Index;
public readonly object Value;
public Entry(int index, object value)
{
Index = index;
Value = value;
}
}
#endregion
}
}
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