Java tutorial
/* * Copyright (c) www.bugull.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.bugull.mongo.decoder; import com.bugull.mongo.BuguEntity; import com.bugull.mongo.BuguQuery; import com.bugull.mongo.annotations.Default; import com.bugull.mongo.annotations.RefList; import com.bugull.mongo.cache.ConstructorCache; import com.bugull.mongo.cache.DaoCache; import com.bugull.mongo.utils.DataType; import com.bugull.mongo.utils.FieldUtil; import com.bugull.mongo.misc.InternalDao; import com.bugull.mongo.utils.Operator; import com.bugull.mongo.utils.ReferenceUtil; import com.mongodb.DBObject; import java.lang.reflect.Array; import java.lang.reflect.Field; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; /** * * @author Frank Wen(xbwen@hotmail.com) */ @SuppressWarnings("unchecked") public class RefListDecoder extends AbstractDecoder { private RefList refList; public RefListDecoder(Field field, DBObject dbo) { super(field); refList = field.getAnnotation(RefList.class); String fieldName = field.getName(); String name = refList.name(); if (!name.equals(Default.NAME)) { fieldName = name; } value = dbo.get(fieldName); } @Override public void decode(Object obj) { Class<?> type = field.getType(); if (type.isArray()) { decodeArray(obj, type.getComponentType()); } else { ParameterizedType paramType = (ParameterizedType) field.getGenericType(); Type[] types = paramType.getActualTypeArguments(); int len = types.length; if (len == 1) { decodeCollection(obj, (Class) types[0]); } else if (len == 2) { decodeMap(obj, (Class) types[1]); } } } private void decodeArray(Object obj, Class clazz) { clazz = FieldUtil.getRealType(clazz, field); List list = (ArrayList) value; int size = list.size(); if (size <= 0) { return; } Object arr = Array.newInstance(clazz, size); if (refList.cascade().toUpperCase().indexOf(Default.CASCADE_READ) == -1) { for (int i = 0; i < size; i++) { Object item = list.get(i); if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); BuguEntity refObj = (BuguEntity) ConstructorCache.getInstance().create(clazz); refObj.setId(refId); Array.set(arr, i, refObj); } else { Array.set(arr, i, null); } } } else { List<String> idList = new ArrayList<String>(); for (int i = 0; i < size; i++) { Object item = list.get(i); if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); idList.add(refId); } } InternalDao dao = DaoCache.getInstance().get(clazz); BuguQuery query = dao.query().in(Operator.ID, idList); String sort = refList.sort(); if (!sort.equals(Default.SORT)) { query.sort(sort); } List<BuguEntity> entityList = query.results(); //when query returns, the size maybe changed if (entityList.size() != size) { size = entityList.size(); arr = Array.newInstance(clazz, size); } for (int i = 0; i < size; i++) { Array.set(arr, i, entityList.get(i)); } } FieldUtil.set(obj, field, arr); } private void decodeCollection(Object obj, Class clazz) { clazz = FieldUtil.getRealType(clazz, field); Collection collection = (Collection) value; List<BuguEntity> result = new ArrayList<BuguEntity>(); if (refList.cascade().toUpperCase().indexOf(Default.CASCADE_READ) == -1) { for (Object item : collection) { if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); BuguEntity refObj = (BuguEntity) ConstructorCache.getInstance().create(clazz); refObj.setId(refId); result.add(refObj); } } } else { List<String> idList = new ArrayList<String>(); for (Object item : collection) { if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); idList.add(refId); } } InternalDao dao = DaoCache.getInstance().get(clazz); BuguQuery query = dao.query().in(Operator.ID, idList); String sort = refList.sort(); if (!sort.equals(Default.SORT)) { query.sort(sort); } result = query.results(); } Class type = field.getType(); if (DataType.isListType(type)) { FieldUtil.set(obj, field, result); } else if (DataType.isSetType(type)) { FieldUtil.set(obj, field, new HashSet(result)); } else if (DataType.isQueueType(type)) { FieldUtil.set(obj, field, new LinkedList(result)); } } private void decodeMap(Object obj, Class clazz) { clazz = FieldUtil.getRealType(clazz, field); Map map = (Map) value; Map<Object, BuguEntity> result = new HashMap<Object, BuguEntity>(); if (refList.cascade().toUpperCase().indexOf(Default.CASCADE_READ) == -1) { for (Object key : map.keySet()) { Object item = map.get(key); if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); BuguEntity refObj = (BuguEntity) ConstructorCache.getInstance().create(clazz); refObj.setId(refId); result.put(key, refObj); } else { result.put(key, null); } } } else { InternalDao dao = DaoCache.getInstance().get(clazz); for (Object key : map.keySet()) { Object item = map.get(key); if (item != null) { String refId = ReferenceUtil.fromDbReference(refList, item); BuguEntity refObj = (BuguEntity) dao.findOne(refId); result.put(key, refObj); } else { result.put(key, null); } } } FieldUtil.set(obj, field, result); } }