edu.harvard.hms.dbmi.bd2k.irct.ws.rs.resultconverter.CSVTabularDataConverter.java Source code

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Here is the source code for edu.harvard.hms.dbmi.bd2k.irct.ws.rs.resultconverter.CSVTabularDataConverter.java

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/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package edu.harvard.hms.dbmi.bd2k.irct.ws.rs.resultconverter;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.StreamingOutput;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import edu.harvard.hms.dbmi.bd2k.irct.dataconverter.ResultDataConverter;
import edu.harvard.hms.dbmi.bd2k.irct.model.result.Result;
import edu.harvard.hms.dbmi.bd2k.irct.model.result.ResultDataType;
import edu.harvard.hms.dbmi.bd2k.irct.model.result.exception.PersistableException;
import edu.harvard.hms.dbmi.bd2k.irct.model.result.exception.ResultSetException;
import edu.harvard.hms.dbmi.bd2k.irct.model.result.tabular.ResultSet;

/**
 * A data converter that returns a CSV Stream
 * 
 * @author Jeremy R. Easton-Marks
 *
 */
public class CSVTabularDataConverter implements ResultDataConverter {

    private Log log;

    public CSVTabularDataConverter() {
        log = LogFactory.getLog("CSV Tabular Data Converter");
    }

    @Override
    public ResultDataType getResultDataType() {
        return ResultDataType.TABULAR;
    }

    @Override
    public String getFileExtension() {
        return ".csv";
    }

    @Override
    public String getName() {
        return "CSV";
    }

    @Override
    public String getMediaType() {
        return "text/csv";
    }

    @Override
    public StreamingOutput createStream(final Result result) {
        StreamingOutput stream = new StreamingOutput() {
            @Override
            public void write(OutputStream outputStream) throws IOException, WebApplicationException {
                ResultSet rs = null;
                CSVPrinter printer = null;
                try {
                    rs = (ResultSet) result.getData();
                    rs.load(result.getResultSetLocation());

                    printer = new CSVPrinter(new OutputStreamWriter(outputStream), CSVFormat.DEFAULT);

                    String[] columnHeaders = new String[rs.getColumnSize()];
                    for (int i = 0; i < rs.getColumnSize(); i++) {
                        columnHeaders[i] = rs.getColumn(i).getName();
                    }
                    printer.printRecord((Object[]) columnHeaders);

                    rs.beforeFirst();
                    while (rs.next()) {
                        String[] row = new String[rs.getColumnSize()];
                        for (int i = 0; i < rs.getColumnSize(); i++) {
                            row[i] = rs.getString(i);
                        }
                        printer.printRecord((Object[]) row);
                    }
                    printer.flush();

                } catch (ResultSetException | PersistableException e) {
                    log.info("Error creating CSV Stream: " + e.getMessage());
                } finally {
                    if (printer != null) {
                        printer.close();
                    }

                    if (rs != null && !rs.isClosed()) {
                        try {
                            rs.close();
                        } catch (ResultSetException e) {
                            e.printStackTrace();
                        }
                    }
                    if (outputStream != null) {
                        outputStream.close();
                    }
                }

            }
        };
        return stream;
    }
}