org.apache.hadoop.chukwa.hicc.DatasetMapper.java Source code

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Here is the source code for org.apache.hadoop.chukwa.hicc.DatasetMapper.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 org.apache.hadoop.chukwa.hicc;

import java.util.HashMap;
import java.util.ArrayList;
import java.util.List;
import java.sql.*;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class DatasetMapper {
    private String jdbc;
    private static Log log = LogFactory.getLog(DatasetMapper.class);
    private HashMap<String, ArrayList<Double>> dataset;
    private List<String> labels;

    public DatasetMapper(String jdbc) {
        this.jdbc = jdbc;
        this.dataset = new HashMap<String, ArrayList<Double>>();
        this.labels = new ArrayList<String>();
    }

    public void execute(String query, boolean groupBySecondColumn) {
        dataset.clear();
        try {
            // The newInstance() call is a work around for some
            // broken Java implementations
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception ex) {
            // handle the error
        }
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        int counter = 0;
        int size = 0;
        labels.clear();
        double max = 0.0;
        int labelsCount = 0;
        try {
            conn = DriverManager.getConnection(jdbc);
            stmt = conn.createStatement();
            //rs = stmt.executeQuery(query);
            if (stmt.execute(query)) {
                rs = stmt.getResultSet();
                ResultSetMetaData rmeta = rs.getMetaData();
                int col = rmeta.getColumnCount();
                int i = 0;
                java.util.ArrayList<Double> data = null;
                HashMap<String, Integer> xAxisMap = new HashMap<String, Integer>();
                while (rs.next()) {
                    String label = rs.getString(1);
                    if (!xAxisMap.containsKey(label)) {
                        xAxisMap.put(label, i);
                        labels.add(label);
                        i++;
                    }
                    if (groupBySecondColumn) {
                        String item = rs.getString(2);
                        // Get the data from the row using the series column
                        double current = rs.getDouble(3);
                        if (current > max) {
                            max = current;
                        }
                        data = dataset.get(item);
                        if (data == null) {
                            data = new java.util.ArrayList<Double>();
                        }
                        data.add(rs.getDouble(3));
                        dataset.put(item, data);
                    } else {
                        for (int j = 2; j <= col; j++) {
                            String item = rmeta.getColumnName(j);
                            // Get the data from the row using the column name
                            double current = rs.getDouble(j);
                            if (current > max) {
                                max = current;
                            }
                            data = dataset.get(item);
                            if (data == null) {
                                data = new java.util.ArrayList<Double>();
                            }
                            data.add(rs.getDouble(j));
                            dataset.put(item, data);
                        }
                    }
                }
                labelsCount = i;
            } else {
                log.error("query is not executed.");
            }
            // Now do something with the ResultSet ....
        } catch (SQLException ex) {
            // handle any errors
            log.error("SQLException: " + ex.getMessage());
            log.error("SQLState: " + ex.getSQLState());
            log.error("VendorError: " + ex.getErrorCode());
        } catch (Exception ex) {
        } finally {
            // it is a good idea to release
            // resources in a finally{} block
            // in reverse-order of their creation
            // if they are no-longer needed
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException sqlEx) {
                    // ignore
                }
                rs = null;
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlEx) {
                    // ignore
                }
                stmt = null;
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException sqlEx) {
                    // ignore
                }
                conn = null;
            }
        }
    }

    public List<String> getXAxisMap() {
        return labels;
    }

    public HashMap<String, ArrayList<Double>> getDataset() {
        return dataset;
    }
}