org.apache.wicket.util.lang.Generics.java Source code

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Here is the source code for org.apache.wicket.util.lang.Generics.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.wicket.util.lang;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Generics related utilities
 * 
 * @author igor.vaynberg
 */
public class Generics {
    private Generics() {

    }

    /**
     * Silences generics warning when need to cast iterator types
     * 
     * @param <T>
     * @param delegate
     * @return <code>delegate</code> iterator cast to proper generics type
     */
    @SuppressWarnings("unchecked")
    public static <T> Iterator<T> iterator(final Iterator<?> delegate) {
        return (Iterator<T>) delegate;
    }

    /**
     * Creates a new HashMap
     * 
     * @param <K>
     * @param <V>
     * @return new hash map
     */
    public static <K, V> HashMap<K, V> newHashMap() {
        return new HashMap<>();
    }

    /**
     * Creates a new HashMap
     * 
     * @param <K>
     * @param <V>
     * @param capacity
     *            initial capacity
     * @return new hash map
     */
    public static <K, V> HashMap<K, V> newHashMap(final int capacity) {
        return new HashMap<>(capacity);
    }

    /**
     * Creates a new ArrayList
     * 
     * @param <T>
     * @param capacity
     *            initial capacity
     * @return array list
     */
    public static <T> ArrayList<T> newArrayList(final int capacity) {
        return new ArrayList<>(capacity);
    }

    /**
     * Creates a new ArrayList
     * 
     * @param <T>
     * @return array list
     */
    public static <T> ArrayList<T> newArrayList() {
        return new ArrayList<>();
    }

    /**
     * Creates a new ConcurrentHashMap
     * 
     * @param <K>
     * @param <V>
     * @return new hash map
     */
    public static <K, V> ConcurrentHashMap<K, V> newConcurrentHashMap() {
        return new ConcurrentHashMap<>();
    }

    /**
     * Creates a new ConcurrentHashMap
     * 
     * @param <K>
     * @param <V>
     * @param initialCapacity
     *            initial capacity
     * @return new hash map
     */
    public static <K, V> ConcurrentHashMap<K, V> newConcurrentHashMap(final int initialCapacity) {
        return new ConcurrentHashMap<>(initialCapacity);
    }

}