CaseInsensitiveContainerFactory.java

/**
 * Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
 *
 * 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.
 */

package com.jfinal.plugin.activerecord;

import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

/**
 * CaseInsensitiveContainerFactory.
 */
public class CaseInsensitiveContainerFactory implements IContainerFactory {
	
	private static Boolean toLowerCase = null;
	
	public CaseInsensitiveContainerFactory() {
	}
	
	public CaseInsensitiveContainerFactory(boolean toLowerCase) {
		CaseInsensitiveContainerFactory.toLowerCase = toLowerCase;
	}
	
	public Map<String, Object> getAttrsMap() {
		return new CaseInsensitiveMap<Object>();
	}
	
	public Map<String, Object> getColumnsMap() {
		return new CaseInsensitiveMap<Object>();
	}
	
	public Set<String> getModifyFlagSet() {
		return new CaseInsensitiveSet();
	}
	
	private static String convertCase(String key) {
		if (toLowerCase != null) {
			return toLowerCase ? key.toLowerCase() : key.toUpperCase();
		} else {
			return key;
		}
	}
	
	/*
	 * 1：非静态内部类拥有对外部类的所有成员的完全访问权限，包括实例字段和方法，
	 *    为实现这一行为，非静态内部类存储着对外部类的实例的一个隐式引用
	 * 2：序列化时要求所有的成员变量是Serializable 包括上面谈到的引式引用
	 * 3：外部类CaseInsensitiveContainerFactory 需要 implements Serializable 才能被序列化
	 * 4：可以使用静态内部类来实现内部类的序列化，而非让外部类实现 implements Serializable 
	 */
	public static class CaseInsensitiveSet extends TreeSet<String> {
		
		private static final long serialVersionUID = 6236541338642353211L;
		
		public CaseInsensitiveSet() {
			super(String.CASE_INSENSITIVE_ORDER);
		}
		
		public boolean add(String e) {
			return super.add(convertCase(e));
		}
		
		public boolean addAll(Collection<? extends String> c) {
			boolean modified = false;
			for (String o : c) {
				if (super.add(convertCase(o))) {
					modified = true;
				}
			}
			return modified;
		}
	}
	
	public static class CaseInsensitiveMap<V> extends TreeMap<String, V> {
		
		private static final long serialVersionUID = 7482853823611007217L;
		
		public CaseInsensitiveMap() {
			super(String.CASE_INSENSITIVE_ORDER);
		}
		
		public V put(String key, V value) {
			return super.put(convertCase(key), value);
		}
		
		public void putAll(Map<? extends String, ? extends V> map) {
			for (Map.Entry<? extends String, ? extends V> e : map.entrySet()) {
				super.put(convertCase(e.getKey()), e.getValue());
			}
		}
	}
}