Java tutorial
//package com.java2s; /* * Copyright (C) 2006 The Android Open Source Project * * 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. */ import java.lang.reflect.Array; public class Main { private static Object[] EMPTY = new Object[0]; private static final int CACHE_SIZE = 73; private static Object[] sCache = new Object[CACHE_SIZE]; /** * Returns an empty array of the specified type. The intent is that * it will return the same empty array every time to avoid reallocation, * although this is not guaranteed. */ public static <T> T[] emptyArray(Class<T> kind) { if (kind == Object.class) { return (T[]) EMPTY; } int bucket = ((System.identityHashCode(kind) / 8) & 0x7FFFFFFF) % CACHE_SIZE; Object cache = sCache[bucket]; if (cache == null || cache.getClass().getComponentType() != kind) { cache = Array.newInstance(kind, 0); sCache[bucket] = cache; // Log.e("cache", "new empty " + kind.getName() + " at " + bucket); } return (T[]) cache; } }