it.greenvulcano.gvesb.datahandling.dbo.utils.ResultSetTransformer.java Source code

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Here is the source code for it.greenvulcano.gvesb.datahandling.dbo.utils.ResultSetTransformer.java

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/*******************************************************************************
 * Copyright (c) 2009, 2016 GreenVulcano ESB Open Source Project.
 * All rights reserved.
 *
 * This file is part of GreenVulcano ESB.
 *
 * GreenVulcano ESB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GreenVulcano ESB is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with GreenVulcano ESB. If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/

package it.greenvulcano.gvesb.datahandling.dbo.utils;

import java.sql.Blob;
import java.sql.Clob;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Base64;
import java.util.List;
import java.util.Optional;

import org.apache.commons.io.IOUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class ResultSetTransformer {

    private final static Logger LOG = LoggerFactory.getLogger(ResultSetTransformer.class);

    public static JSONArray toJSONArray(ResultSet resultSet) throws SQLException {

        JSONArray queryResult = new JSONArray();

        int columns = resultSet.getMetaData().getColumnCount();
        List<String> names = new ArrayList<>(columns);
        for (int i = 1; i <= columns; i++) {
            names.add(resultSet.getMetaData().getColumnLabel(i));
        }

        while (resultSet.next()) {

            JSONObject obj = new JSONObject();
            for (String key : names) {

                Object jsonValue = parseValue(resultSet.getObject(key));

                if (key.contains(".")) {
                    String[] hieararchy = key.split("\\.");

                    JSONObject child = Optional.ofNullable(obj.optJSONObject(hieararchy[0]))
                            .orElse(new JSONObject());
                    child.put(hieararchy[1], Optional.ofNullable(jsonValue).orElse(JSONObject.NULL));

                    obj.put(hieararchy[0], child);
                } else {
                    obj.put(key, Optional.ofNullable(jsonValue).orElse(JSONObject.NULL));
                }
            }

            queryResult.put(obj);
        }

        return queryResult;

    }

    private static Object parseValue(Object object) {
        try {
            if (object instanceof Blob) {

                byte[] blob = IOUtils.toByteArray(Blob.class.cast(object).getBinaryStream());
                object = Base64.getEncoder().encodeToString(blob);
            }
        } catch (Exception e) {
            LOG.error("Something goes wrong parsing BLOB field", e);
            object = "Unparsable BLOB";
        }

        try {

            if (object instanceof Clob) {

                byte[] clob = IOUtils.toByteArray(Clob.class.cast(object).getAsciiStream());
                object = new String(clob, "UTF-8");
            }

        } catch (Exception e) {
            LOG.error("Something goes wrong parsing CLOB field", e);
            object = "Unparsable CLOB";
        }

        if (object instanceof String) {

            String value = String.class.cast(object).trim();

            try {
                if (value.startsWith("{") && value.endsWith("}")) {
                    return new JSONObject(value);

                } else if (value.startsWith("[") && value.endsWith("]")) {
                    return new JSONArray(value);
                }
            } catch (JSONException e) {
                LOG.warn("Something goes wrong parsing " + value + " as JSON");
            }

        }

        return object;

    }

}