io.pivotal.tzolov.gemfire.adapter.GemfireHawqAdapterService.java Source code

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Here is the source code for io.pivotal.tzolov.gemfire.adapter.GemfireHawqAdapterService.java

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/**
 * 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 io.pivotal.tzolov.gemfire.adapter;

import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class GemfireHawqAdapterService {

    private String hostName;

    private String port;

    private String columnDelimiter;

    @Autowired
    public GemfireHawqAdapterService(@Value("${gf.host:localhost}") String gemfireHostName,
            @Value("${gf.port:8081}") String gemfirePort,
            @Value("${gf.columnDelimiter:|}") String columnDelimiter) {

        this.hostName = gemfireHostName;
        this.port = gemfirePort;
        this.columnDelimiter = columnDelimiter;
    }

    @SuppressWarnings("rawtypes")
    public void runAdhocQuery(String oqlQuery, Writer writer) throws Exception {

        List rows = new RestTemplate().getForObject(
                "http://{hostname}:{port}/gemfire-api/v1/queries/adhoc?q={query}", List.class, hostName, port,
                oqlQuery);

        processResponse(rows, writer);
    }

    @SuppressWarnings("rawtypes")
    public void runNamedQuery(String queryId, String requestBody, Writer writer) throws Exception {

        List rows = new RestTemplate().postForObject("http://{hostname}:{port}/gemfire-api/v1/queries/{queryId}",
                requestBody, List.class, hostName, port, queryId);

        processResponse(rows, writer);
    }

    private void processResponse(List rows, Writer writer) throws IOException {
        for (Object row : rows) {

            String outputRow = "";

            if (row instanceof String) {
                outputRow = (String) row;
            } else if (row instanceof Map) {

                Map mapItem = ((Map) row);

                int i = 0;
                for (Object value : mapItem.values()) {
                    i++;
                    String columnValue = toColumnValue(value);
                    outputRow = (i == 1) ? columnValue : outputRow + columnDelimiter + columnValue;
                }
            } else {
                throw new IllegalStateException("Unsupported return class type: " + row.getClass());
            }

            writer.write(outputRow);
            writer.write("\n");
        }
    }

    /**
     * Naive escape logic
     * 
     * @param value
     *            - input value to clean
     * @return Returns escaped value
     */
    private String toColumnValue(Object value) {

        String valueStr = "";

        if (value != null) {
            valueStr = value.toString();
            valueStr = valueStr.replace("\\", "\\\\");
            valueStr = valueStr.replace("|", "\\|");
            valueStr = valueStr.replace("\t", " ");
            valueStr = valueStr.replace("\r", " ");
            valueStr = valueStr.replace("\n", " ");
            valueStr = valueStr.replace("\0", "");
        }

        return valueStr;
    }

}