org.jongo.stream.JacksonDBDecoder.java Source code

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Here is the source code for org.jongo.stream.JacksonDBDecoder.java

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/*
 * Copyright 2011 VZ Netzwerke Ltd
 *
 * 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 org.jongo.stream;

import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.core.util.BufferRecycler;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mongodb.DBCallback;
import com.mongodb.DBCollection;
import com.mongodb.DBDecoder;
import com.mongodb.DBObject;
import org.bson.BSONCallback;
import org.bson.BSONObject;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * DB decoder that decodes the database stream using Jackson and bson4jackson
 *
 * @author James Roper
 * @since 1.1.2
 */
public class JacksonDBDecoder<T> implements DBDecoder {

    private final ObjectMapper objectMapper;
    private final JavaType type;

    public JacksonDBDecoder(ObjectMapper objectMapper, JavaType type) {
        this.objectMapper = objectMapper;
        this.type = type;
    }

    public DBCallback getDBCallback(DBCollection collection) {
        throw new UnsupportedOperationException("JacksonDBDecoder does not support callback style decoding");
    }

    public DBObject decode(byte[] b, DBCollection collection) {
        try {
            return decode(new ByteArrayInputStream(b), collection);
        } catch (IOException e) {
            // Not possible
            throw new RuntimeException("IOException encountered while reading from a byte array input stream", e);
        }
    }

    public DBObject decode(InputStream in, DBCollection collection) throws IOException {
        JacksonDBObject<T> decoded = new JacksonDBObject<T>();
        decoded.setObject(
                (T) objectMapper.readValue(new DBDecoderBsonParser(new IOContext(new BufferRecycler(), in, false),
                        0, in, decoded, objectMapper), type));
        return decoded;
    }

    public BSONObject readObject(byte[] b) {
        return decode(b, (DBCollection) null);
    }

    public BSONObject readObject(InputStream in) throws IOException {
        return decode(in, (DBCollection) null);
    }

    public int decode(byte[] b, BSONCallback callback) {
        throw new UnsupportedOperationException("JacksonDBDecoder does not support callback style decoding");
    }

    public int decode(InputStream in, BSONCallback callback) throws IOException {
        throw new UnsupportedOperationException("JacksonDBDecoder does not support callback style decoding");
    }
}