EmbedListDecoder.java

/*
 * 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 net.tooan.ynpay.third.mongodb.decoder;

import com.mongodb.DBObject;
import net.tooan.ynpay.third.mongodb.annotations.Default;
import net.tooan.ynpay.third.mongodb.annotations.EmbedList;
import net.tooan.ynpay.third.mongodb.mapper.DataType;
import net.tooan.ynpay.third.mongodb.mapper.FieldUtil;
import net.tooan.ynpay.third.mongodb.mapper.MapperUtil;

import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.*;

/**
 * @author Frank Wen(xbwen@hotmail.com)
 */
@SuppressWarnings("unchecked")
public class EmbedListDecoder extends AbstractDecoder {

    public EmbedListDecoder(Field field, DBObject dbo) {
        super(field);
        String fieldName = field.getName();
        EmbedList embedList = field.getAnnotation(EmbedList.class);
        String name = embedList.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) {
                decodeList(obj, (Class) types[0]);
            } else {
                decodeMap(obj, (Class) types[1]);
            }
        }
    }

    private void decodeArray(Object obj, Class clazz) {
        List list = (ArrayList) value;
        int size = list.size();
        Object arr = Array.newInstance(clazz, size);
        for (int i = 0; i < size; i++) {
            Object item = list.get(i);
            if (item != null) {
                DBObject o = (DBObject) item;
                Array.set(arr, i, MapperUtil.fromDBObject(clazz, o));
            } else {
                Array.set(arr, i, null);
            }
        }
        FieldUtil.set(obj, field, arr);
    }

    private void decodeList(Object obj, Class clazz) {
        List list = (ArrayList) value;
        List result = new ArrayList();
        for (Object o : list) {
            if (o != null) {
                Object embedObj = MapperUtil.fromDBObject(clazz, (DBObject) o);
                result.add(embedObj);
            }
        }
        Class type = field.getType();
        if (DataType.isList(type)) {
            FieldUtil.set(obj, field, result);
        } else if (DataType.isSet(type)) {
            FieldUtil.set(obj, field, new HashSet(result));
        }
    }

    private void decodeMap(Object obj, Class clazz) {
        Map map = (Map) value;
        Map result = new HashMap();
        for (Object key : map.keySet()) {
            Object val = map.get(key);
            if (val != null) {
                Object embedObj = MapperUtil.fromDBObject(clazz, (DBObject) val);
                result.put(key, embedObj);
            } else {
                result.put(key, null);
            }
        }
        FieldUtil.set(obj, field, result);
    }

}