org.apache.tajo.storage.json.JsonLineSerializer.java Source code

Introduction

Here is the source code for org.apache.tajo.storage.json.JsonLineSerializer.java

Source

/**
 * 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 org.apache.tajo.storage.json;

import net.minidev.json.JSONObject;
import org.apache.commons.net.util.Base64;
import org.apache.tajo.catalog.NestedPathUtil;
import org.apache.tajo.catalog.Schema;
import org.apache.tajo.catalog.SchemaUtil;
import org.apache.tajo.catalog.TableMeta;
import org.apache.tajo.common.TajoDataTypes.Type;
import org.apache.tajo.datum.TextDatum;
import org.apache.tajo.datum.TimestampDatum;
import org.apache.tajo.exception.NotImplementedException;
import org.apache.tajo.exception.TajoRuntimeException;
import org.apache.tajo.storage.StorageConstants;
import org.apache.tajo.storage.StorageUtil;
import org.apache.tajo.storage.Tuple;
import org.apache.tajo.storage.text.TextLineSerializer;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Map;
import java.util.TimeZone;

public class JsonLineSerializer extends TextLineSerializer {
    // Full Path -> Type
    private final Map<String, Type> types;
    private final String[] projectedPaths;

    private final TimeZone timezone;

    public JsonLineSerializer(Schema schema, TableMeta meta) {
        super(schema, meta);

        projectedPaths = SchemaUtil.convertColumnsToPaths(schema.getAllColumns(), true);
        types = SchemaUtil.buildTypeMap(schema.getAllColumns(), projectedPaths);

        timezone = TimeZone.getTimeZone(
                meta.getProperty(StorageConstants.TIMEZONE, StorageUtil.TAJO_CONF.getSystemTimezone().getID()));
    }

    @Override
    public void init() {
    }

    private void putValue(JSONObject json, String fullPath, String[] pathElements, int depth, int fieldIndex,
            Tuple input) throws IOException {
        String fieldName = pathElements[depth];

        if (input.isBlankOrNull(fieldIndex)) {
            return;
        }

        switch (types.get(fullPath)) {

        case BOOLEAN:
            json.put(fieldName, input.getBool(fieldIndex));
            break;

        case INT1:
        case INT2:
            json.put(fieldName, input.getInt2(fieldIndex));
            break;

        case INT4:
            json.put(fieldName, input.getInt4(fieldIndex));
            break;

        case INT8:
            json.put(fieldName, input.getInt8(fieldIndex));
            break;

        case FLOAT4:
            json.put(fieldName, input.getFloat4(fieldIndex));
            break;

        case FLOAT8:
            json.put(fieldName, input.getFloat8(fieldIndex));
            break;

        case TEXT:
        case VARCHAR:
            json.put(fieldName, input.getText(fieldIndex));
            break;

        case CHAR:
        case DATE:
        case INTERVAL:
            json.put(fieldName, input.asDatum(fieldIndex).asChars());
            break;

        case TIMESTAMP:
            json.put(fieldName, TimestampDatum.asChars(input.getTimeDate(fieldIndex), timezone, false));
            break;
        case TIME:
            json.put(fieldName, input.asDatum(fieldIndex).asChars());
            break;

        case BIT:
        case BINARY:
        case BLOB:
        case VARBINARY:
            json.put(fieldName, Base64.encodeBase64String(input.getBytes(fieldIndex)));
            break;

        case NULL_TYPE:
            break;

        case RECORD:
            JSONObject record = json.containsKey(fieldName) ? (JSONObject) json.get(fieldName) : new JSONObject();
            json.put(fieldName, record);
            putValue(record, fullPath + "/" + pathElements[depth + 1], pathElements, depth + 1, fieldIndex, input);
            break;

        default:
            throw new TajoRuntimeException(
                    new NotImplementedException("" + types.get(fullPath).name() + " for json"));
        }
    }

    @Override
    public int serialize(OutputStream out, Tuple input) throws IOException {
        JSONObject jsonObject = new JSONObject();

        for (int i = 0; i < projectedPaths.length; i++) {
            String[] paths = projectedPaths[i].split(NestedPathUtil.PATH_DELIMITER);
            putValue(jsonObject, paths[0], paths, 0, i, input);
        }

        String jsonStr = jsonObject.toJSONString();
        byte[] jsonBytes = jsonStr.getBytes(TextDatum.DEFAULT_CHARSET);
        out.write(jsonBytes);
        return jsonBytes.length;
    }

    @Override
    public void release() {
    }
}