com.streamsets.pipeline.lib.jdbc.MultiRowInsertMap.java Source code

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Here is the source code for com.streamsets.pipeline.lib.jdbc.MultiRowInsertMap.java

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/**
 * Copyright 2015 StreamSets Inc.
 *
 * Licensed under 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 com.streamsets.pipeline.lib.jdbc;

import com.google.common.base.Joiner;
import org.apache.commons.lang3.StringUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedMap;

class MultiRowInsertMap {
    private final Connection connection;
    private final String tableName;
    private final Map<SortedMap<String, String>, PreparedStatement> cache = new HashMap<>();

    public MultiRowInsertMap(Connection connection, String tableName) {
        this.connection = connection;
        this.tableName = tableName;
    }

    public PreparedStatement getInsertFor(SortedMap<String, String> columns, int numRecords) throws SQLException {
        // The INSERT query we're going to perform (parameterized).
        if (cache.containsKey(columns)) {
            return cache.get(columns);
        } else {
            String valuePlaceholder = String.format("(%s)", Joiner.on(", ").join(columns.values()));
            String valuePlaceholders = StringUtils.repeat(valuePlaceholder, ", ", numRecords);
            String query = String.format("INSERT INTO %s (%s) VALUES %s", tableName,
                    // keySet and values will both return the same ordering, due to using a SortedMap
                    Joiner.on(", ").join(columns.keySet()), valuePlaceholders);
            PreparedStatement statement = connection.prepareStatement(query);
            cache.put(columns, statement);
            return statement;
        }
    }

    public final Collection<PreparedStatement> getStatements() {
        return cache.values();
    }

    public void executeStatements() throws SQLException {
        for (PreparedStatement statement : cache.values()) {
            statement.executeBatch();
            statement.close();
        }
    }
}