Examples with CsvOutputOptions org.apache.nifi.util.hive.CsvOutputOptions used on opensource projects

Example 1 with CsvOutputOptions

use of org.apache.nifi.util.hive.CsvOutputOptions in project nifi by apache.

the class SelectHiveQL method onTrigger.

private void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException {
    FlowFile fileToProcess = (context.hasIncomingConnection() ? session.get() : null);
    FlowFile flowfile = null;
    // we know that we should run only if we have a FlowFile.
    if (context.hasIncomingConnection()) {
        if (fileToProcess == null && context.hasNonLoopConnection()) {
            return;
        }
    }
    final ComponentLog logger = getLogger();
    final HiveDBCPService dbcpService = context.getProperty(HIVE_DBCP_SERVICE).asControllerService(HiveDBCPService.class);
    final Charset charset = Charset.forName(context.getProperty(CHARSET).getValue());
    final boolean flowbased = !(context.getProperty(HIVEQL_SELECT_QUERY).isSet());
    // Source the SQL
    final String selectQuery;
    if (context.getProperty(HIVEQL_SELECT_QUERY).isSet()) {
        selectQuery = context.getProperty(HIVEQL_SELECT_QUERY).evaluateAttributeExpressions(fileToProcess).getValue();
    } else {
        // If the query is not set, then an incoming flow file is required, and expected to contain a valid SQL select query.
        // If there is no incoming connection, onTrigger will not be called as the processor will fail when scheduled.
        final StringBuilder queryContents = new StringBuilder();
        session.read(fileToProcess, in -> queryContents.append(IOUtils.toString(in, charset)));
        selectQuery = queryContents.toString();
    }
    final Integer fetchSize = context.getProperty(FETCH_SIZE).evaluateAttributeExpressions(fileToProcess).asInteger();
    final Integer maxRowsPerFlowFile = context.getProperty(MAX_ROWS_PER_FLOW_FILE).evaluateAttributeExpressions(fileToProcess).asInteger();
    final Integer maxFragments = context.getProperty(MAX_FRAGMENTS).isSet() ? context.getProperty(MAX_FRAGMENTS).evaluateAttributeExpressions(fileToProcess).asInteger() : 0;
    final String outputFormat = context.getProperty(HIVEQL_OUTPUT_FORMAT).getValue();
    final boolean convertNamesForAvro = context.getProperty(NORMALIZE_NAMES_FOR_AVRO).asBoolean();
    final StopWatch stopWatch = new StopWatch(true);
    final boolean header = context.getProperty(HIVEQL_CSV_HEADER).asBoolean();
    final String altHeader = context.getProperty(HIVEQL_CSV_ALT_HEADER).evaluateAttributeExpressions(fileToProcess).getValue();
    final String delimiter = context.getProperty(HIVEQL_CSV_DELIMITER).evaluateAttributeExpressions(fileToProcess).getValue();
    final boolean quote = context.getProperty(HIVEQL_CSV_QUOTE).asBoolean();
    final boolean escape = context.getProperty(HIVEQL_CSV_HEADER).asBoolean();
    final String fragmentIdentifier = UUID.randomUUID().toString();
    try (final Connection con = dbcpService.getConnection();
        final Statement st = (flowbased ? con.prepareStatement(selectQuery) : con.createStatement())) {
        if (fetchSize != null && fetchSize > 0) {
            try {
                st.setFetchSize(fetchSize);
            } catch (SQLException se) {
                // Not all drivers support this, just log the error (at debug level) and move on
                logger.debug("Cannot set fetch size to {} due to {}", new Object[] { fetchSize, se.getLocalizedMessage() }, se);
            }
        }
        final List<FlowFile> resultSetFlowFiles = new ArrayList<>();
        try {
            logger.debug("Executing query {}", new Object[] { selectQuery });
            if (flowbased) {
                // Hive JDBC Doesn't Support this yet:
                // ParameterMetaData pmd = ((PreparedStatement)st).getParameterMetaData();
                // int paramCount = pmd.getParameterCount();
                // Alternate way to determine number of params in SQL.
                int paramCount = StringUtils.countMatches(selectQuery, "?");
                if (paramCount > 0) {
                    setParameters(1, (PreparedStatement) st, paramCount, fileToProcess.getAttributes());
                }
            }
            final ResultSet resultSet;
            try {
                resultSet = (flowbased ? ((PreparedStatement) st).executeQuery() : st.executeQuery(selectQuery));
            } catch (SQLException se) {
                // If an error occurs during the query, a flowfile is expected to be routed to failure, so ensure one here
                flowfile = (fileToProcess == null) ? session.create() : fileToProcess;
                fileToProcess = null;
                throw se;
            }
            int fragmentIndex = 0;
            String baseFilename = (fileToProcess != null) ? fileToProcess.getAttribute(CoreAttributes.FILENAME.key()) : null;
            while (true) {
                final AtomicLong nrOfRows = new AtomicLong(0L);
                flowfile = (flowfile == null) ? session.create() : session.create(flowfile);
                if (baseFilename == null) {
                    baseFilename = flowfile.getAttribute(CoreAttributes.FILENAME.key());
                }
                try {
                    flowfile = session.write(flowfile, out -> {
                        try {
                            if (AVRO.equals(outputFormat)) {
                                nrOfRows.set(HiveJdbcCommon.convertToAvroStream(resultSet, out, maxRowsPerFlowFile, convertNamesForAvro));
                            } else if (CSV.equals(outputFormat)) {
                                CsvOutputOptions options = new CsvOutputOptions(header, altHeader, delimiter, quote, escape, maxRowsPerFlowFile);
                                nrOfRows.set(HiveJdbcCommon.convertToCsvStream(resultSet, out, options));
                            } else {
                                nrOfRows.set(0L);
                                throw new ProcessException("Unsupported output format: " + outputFormat);
                            }
                        } catch (final SQLException | RuntimeException e) {
                            throw new ProcessException("Error during database query or conversion of records.", e);
                        }
                    });
                } catch (ProcessException e) {
                    // Add flowfile to results before rethrowing so it will be removed from session in outer catch
                    resultSetFlowFiles.add(flowfile);
                    throw e;
                }
                if (nrOfRows.get() > 0 || resultSetFlowFiles.isEmpty()) {
                    final Map<String, String> attributes = new HashMap<>();
                    // Set attribute for how many rows were selected
                    attributes.put(RESULT_ROW_COUNT, String.valueOf(nrOfRows.get()));
                    try {
                        // Set input/output table names by parsing the query
                        attributes.putAll(toQueryTableAttributes(findTableNames(selectQuery)));
                    } catch (Exception e) {
                        // If failed to parse the query, just log a warning message, but continue.
                        getLogger().warn("Failed to parse query: {} due to {}", new Object[] { selectQuery, e }, e);
                    }
                    // Set MIME type on output document and add extension to filename
                    if (AVRO.equals(outputFormat)) {
                        attributes.put(CoreAttributes.MIME_TYPE.key(), MIME_TYPE_AVRO_BINARY);
                        attributes.put(CoreAttributes.FILENAME.key(), baseFilename + "." + fragmentIndex + ".avro");
                    } else if (CSV.equals(outputFormat)) {
                        attributes.put(CoreAttributes.MIME_TYPE.key(), CSV_MIME_TYPE);
                        attributes.put(CoreAttributes.FILENAME.key(), baseFilename + "." + fragmentIndex + ".csv");
                    }
                    if (maxRowsPerFlowFile > 0) {
                        attributes.put("fragment.identifier", fragmentIdentifier);
                        attributes.put("fragment.index", String.valueOf(fragmentIndex));
                    }
                    flowfile = session.putAllAttributes(flowfile, attributes);
                    logger.info("{} contains {} Avro records; transferring to 'success'", new Object[] { flowfile, nrOfRows.get() });
                    if (context.hasIncomingConnection()) {
                        // If the flow file came from an incoming connection, issue a Fetch provenance event
                        session.getProvenanceReporter().fetch(flowfile, dbcpService.getConnectionURL(), "Retrieved " + nrOfRows.get() + " rows", stopWatch.getElapsed(TimeUnit.MILLISECONDS));
                    } else {
                        // If we created a flow file from rows received from Hive, issue a Receive provenance event
                        session.getProvenanceReporter().receive(flowfile, dbcpService.getConnectionURL(), stopWatch.getElapsed(TimeUnit.MILLISECONDS));
                    }
                    resultSetFlowFiles.add(flowfile);
                } else {
                    // If there were no rows returned (and the first flow file has been sent, we're done processing, so remove the flowfile and carry on
                    session.remove(flowfile);
                    break;
                }
                fragmentIndex++;
                if (maxFragments > 0 && fragmentIndex >= maxFragments) {
                    break;
                }
            }
            for (int i = 0; i < resultSetFlowFiles.size(); i++) {
                // Set count on all FlowFiles
                if (maxRowsPerFlowFile > 0) {
                    resultSetFlowFiles.set(i, session.putAttribute(resultSetFlowFiles.get(i), "fragment.count", Integer.toString(fragmentIndex)));
                }
            }
        } catch (final SQLException e) {
            throw e;
        }
        session.transfer(resultSetFlowFiles, REL_SUCCESS);
    } catch (final ProcessException | SQLException e) {
        logger.error("Issue processing SQL {} due to {}.", new Object[] { selectQuery, e });
        if (flowfile == null) {
            // This can happen if any exceptions occur while setting up the connection, statement, etc.
            logger.error("Unable to execute HiveQL select query {} due to {}. No FlowFile to route to failure", new Object[] { selectQuery, e });
            context.yield();
        } else {
            if (context.hasIncomingConnection()) {
                logger.error("Unable to execute HiveQL select query {} for {} due to {}; routing to failure", new Object[] { selectQuery, flowfile, e });
                flowfile = session.penalize(flowfile);
            } else {
                logger.error("Unable to execute HiveQL select query {} due to {}; routing to failure", new Object[] { selectQuery, e });
                context.yield();
            }
            session.transfer(flowfile, REL_FAILURE);
        }
    } finally {
        if (fileToProcess != null) {
            session.remove(fileToProcess);
        }
    }
}