me.tfeng.play.mongodb.MongoDbTypeConverter.java Source code

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Here is the source code for me.tfeng.play.mongodb.MongoDbTypeConverter.java

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/**
 * Copyright 2014 Thomas Feng
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 me.tfeng.play.mongodb;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;
import java.util.TimeZone;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;
import org.bson.types.BSONTimestamp;
import org.bson.types.ObjectId;

import com.google.common.collect.ImmutableMap;
import com.mongodb.DBObject;
import com.mongodb.util.JSON;
import com.mongodb.util.JSONCallback;

/**
 * @author Thomas Feng (huining.feng@gmail.com)
 */
public class MongoDbTypeConverter {

    public static interface Converter<S, T> {

        public T convertFromMongoDbType(S data);

        public S convertToMongoDbType(T object);
    }

    public static class BSONTimestampToLongConverter implements Converter<BSONTimestamp, Long> {

        @Override
        public Long convertFromMongoDbType(BSONTimestamp data) {
            int inc = data.getInc();
            if (inc < 0 || inc >= 1000) {
                throw new RuntimeException("Overflow occurs while converting BSONTimestamp into long: " + data);
            }
            return (long) data.getTime() * 1000 + inc;
        }

        @Override
        public BSONTimestamp convertToMongoDbType(Long object) {
            return new BSONTimestamp((int) (object / 1000), (int) (object % 1000));
        }
    }

    public static class BSONTimestampToStringConverter implements Converter<BSONTimestamp, String> {

        @Override
        public String convertFromMongoDbType(BSONTimestamp timestamp) {
            return "(" + timestamp.getTime() + ", " + timestamp.getInc() + ")";
        }

        @Override
        public BSONTimestamp convertToMongoDbType(String data) {
            Matcher matcher = TIMESTAMP_PATTERN.matcher(data);
            if (!matcher.matches()) {
                throw new RuntimeException("Invalid BSONTimestamp " + data);
            }
            int time = Integer.parseInt(matcher.group(1));
            int inc = Integer.parseInt(matcher.group(2));
            return new BSONTimestamp(time, inc);
        }
    }

    public static class DateToLongConverter implements Converter<Date, Long> {

        @Override
        public Long convertFromMongoDbType(Date data) {
            return data.getTime();
        }

        @Override
        public Date convertToMongoDbType(Long object) {
            return new Date(object);
        }
    }

    public static class DateToStringConverter implements Converter<Date, String> {

        @Override
        public String convertFromMongoDbType(Date object) {
            return DATE_FORMAT.format(object);
        }

        @Override
        public Date convertToMongoDbType(String data) {
            try {
                return DATE_FORMAT.parse(data);
            } catch (ParseException e) {
                throw new RuntimeException("String does not confirm to date format: " + data);
            }
        }
    }

    public static class ObjectIdToStringConverter implements Converter<ObjectId, String> {

        @Override
        public String convertFromMongoDbType(ObjectId objectId) {
            return objectId.toString();
        }

        @Override
        public ObjectId convertToMongoDbType(String data) {
            return new ObjectId(data);
        }
    }

    public static final Map<Pair<Class<?>, Class<?>>, Converter<?, ?>> CONVERTER_MAP = ImmutableMap
            .<Pair<Class<?>, Class<?>>, Converter<?, ?>>builder()
            .put(ImmutablePair.of(BSONTimestamp.class, Long.class), new BSONTimestampToLongConverter())
            .put(ImmutablePair.of(BSONTimestamp.class, String.class), new BSONTimestampToStringConverter())
            .put(ImmutablePair.of(Date.class, Long.class), new DateToLongConverter())
            .put(ImmutablePair.of(Date.class, String.class), new DateToStringConverter())
            .put(ImmutablePair.of(ObjectId.class, String.class), new ObjectIdToStringConverter()).build();

    public static final DateFormat DATE_FORMAT = new SimpleDateFormat(JSONCallback._msDateFormat);

    public static final Pattern TIMESTAMP_PATTERN = Pattern.compile("\\(([0-9]+),\\s*([0-9]+)\\)");

    static {
        DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
    }

    public static <S, T> T convertFromMongoDbType(Class<T> dataClass, S object) {
        if (object == null) {
            return null;
        } else if (dataClass.isInstance(object)) {
            return dataClass.cast(object);
        } else {
            @SuppressWarnings("unchecked")
            Converter<S, T> converter = (Converter<S, T>) CONVERTER_MAP
                    .get(ImmutablePair.of(object.getClass(), dataClass));
            if (converter != null) {
                return converter.convertFromMongoDbType(object);
            } else if (String.class.isAssignableFrom(dataClass) && object instanceof DBObject) {
                return dataClass.cast(JSON.serialize(object));
            } else {
                return null;
            }
        }
    }

    public static <S, T> S convertToMongoDbType(Class<S> mongoClass, T data) {
        if (data == null) {
            return null;
        } else if (mongoClass.isInstance(data)) {
            return mongoClass.cast(data);
        } else {
            @SuppressWarnings("unchecked")
            Converter<S, T> converter = (Converter<S, T>) CONVERTER_MAP
                    .get(ImmutablePair.of(mongoClass, data.getClass()));
            if (converter != null) {
                return converter.convertToMongoDbType(data);
            } else if (DBObject.class.isAssignableFrom(mongoClass) && data instanceof String) {
                return mongoClass.cast(JSON.parse((String) data));
            } else {
                return null;
            }
        }
    }
}