58 lines
1.6 KiB
Java
58 lines
1.6 KiB
Java
/**
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* Copyright (c) 2011-2017, James Zhan 詹波 (jfinal@126.com).
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.jfinal.template.expr.ast;
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import java.lang.reflect.Field;
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import java.util.HashMap;
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/**
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* FieldKit
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*/
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public class FieldKit {
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private static final HashMap<Long, Object> fieldCache = new HashMap<Long, Object>();
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public static Field getField(Long key, Class<?> targetClass, String fieldName) {
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Object field = fieldCache.get(key);
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if (field == null) {
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field = doGetField(targetClass, fieldName);
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if (field != null) {
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fieldCache.put(key, field);
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} else {
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// 对于不存在的 Field，只进行一次获取操作，主要为了支持 null safe，未来需要考虑内存泄漏风险
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fieldCache.put(key, Boolean.FALSE);
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}
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}
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return field instanceof Field ? (Field)field : null;
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}
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private static Field doGetField(Class<?> targetClass, String fieldName) {
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Field[] fs = targetClass.getFields();
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for (Field f : fs) {
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if (f.getName().equals(fieldName)) {
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return f;
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}
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}
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return null;
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}
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}
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