com.github.ferstl.spring.jdbc.oracle.ParameterizedBatchingPreparedStatementCallback.java Source code

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Here is the source code for com.github.ferstl.spring.jdbc.oracle.ParameterizedBatchingPreparedStatementCallback.java

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/*
 * Copyright (c) 2013 by Stefan Ferstl <st.ferstl@gmail.com>
 *
 * Licensed 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.github.ferstl.spring.jdbc.oracle;

import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.ParameterizedPreparedStatementSetter;
import org.springframework.jdbc.core.PreparedStatementCallback;

import oracle.jdbc.OraclePreparedStatement;

/**
 * {@link PreparedStatementCallback} that uses Oracle Update Batching.
 */
class ParameterizedBatchingPreparedStatementCallback<T> implements PreparedStatementCallback<int[][]> {

    private final ParameterizedPreparedStatementSetter<T> ppss;
    private final int sendBatchSize;
    private final List<T> batchArgs;

    /**
     * Constructor.
     * @param ppss Parameterized Prepared Statement Setter.
     * @param sendBatchSize Size of the batch that will be sent to the DB.
     * @param batchArgs Batch arguments.
     */
    public ParameterizedBatchingPreparedStatementCallback(ParameterizedPreparedStatementSetter<T> ppss,
            int sendBatchSize, Collection<T> batchArgs) {

        this.ppss = ppss;
        this.sendBatchSize = sendBatchSize < batchArgs.size() ? sendBatchSize : batchArgs.size();
        this.batchArgs = new ArrayList<>(batchArgs);
    }

    @Override
    public int[][] doInPreparedStatement(PreparedStatement ps) throws SQLException, DataAccessException {
        OraclePreparedStatement ops = ps.unwrap(OraclePreparedStatement.class);

        List<int[]> rowCounts = new ArrayList<>();
        for (int i = 0; i < this.batchArgs.size(); i += this.sendBatchSize) {
            int remainder = this.batchArgs.size() - i;
            int batchSize = remainder < this.sendBatchSize ? remainder : this.sendBatchSize;

            int[] rowCountsCurrentBatch = new int[batchSize];
            rowCounts.add(rowCountsCurrentBatch);
            ops.setExecuteBatch(batchSize);

            List<T> batch = this.batchArgs.subList(i, i + batchSize);
            for (int j = 0; j < batchSize; j++) {
                this.ppss.setValues(ops, batch.get(j));
                rowCountsCurrentBatch[j] = ops.executeUpdate();
            }
        }

        return rowCounts.toArray(new int[rowCounts.size()][]);
    }

}