Groovy example source code file (BatchingStatementWrapper.java)

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Java - Groovy tags/keywords

arraylist, batchingstatementwrapper, batchingstatementwrapper, groovyobjectsupport, jdbc, log, logger, logging, object, object, override, problem, problem, sql, sqlexception, sqlexception, statement, successfully, util

The Groovy BatchingStatementWrapper.java source code

/*
 * Copyright 2003-2011 the original author or authors.
 *
 * 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 groovy.sql;

import groovy.lang.GroovyObjectSupport;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;
import org.codehaus.groovy.runtime.InvokerHelper;

import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;

/**
 * Class which delegates to a Statement but keeps track of a batch count size.
 * If the batch count reaches the predefined number, this Statement does an executeBatch()
 * automatically. If batchSize is zero, then no batching is performed.
 */
public class BatchingStatementWrapper extends GroovyObjectSupport {
    private Statement delegate;
    protected int batchSize;
    protected int batchCount;
    protected Logger log;
    protected List<Integer> results;

    public BatchingStatementWrapper(Statement delegate, int batchSize, Logger log) {
        this.delegate = delegate;
        this.batchSize = batchSize;
        this.log = log;
        reset();
    }

    protected void reset() {
        batchCount = 0;
        results = new ArrayList<Integer>();
    }

    @Override
    public Object invokeMethod(String name, Object args) {
        return InvokerHelper.invokeMethod(delegate, name, args);
    }

    public void addBatch(String sql) throws SQLException {
        delegate.addBatch(sql);
        batchCount++;
        if (batchCount == batchSize /* never true for batchSize of 0 */) {
            int[] result = delegate.executeBatch();
            processResult(result);
            batchCount = 0;
        }
    }

    public void clearBatch() throws SQLException {
        if (batchSize != 0) {
            reset();
        }
        delegate.clearBatch();
    }

    public int[] executeBatch() throws SQLException {
        int[] lastResult = delegate.executeBatch();
        processResult(lastResult);
        int[] result = new int[results.size()];
        for (int i = 0; i < results.size(); i++) {
            result[i] = results.get(i);
        }
        reset();
        return result;
    }

    protected void processResult(int[] lastResult) {
        boolean foundError = false;
        for (int i : lastResult) {
            if (i == Statement.EXECUTE_FAILED) foundError = true;
            results.add(i);
        }
        // A little bit of paranoid checking here? Most drivers will throw BatchUpdateException perhaps?
        if (batchCount != lastResult.length) {
            log.warning("Problem executing batch - expected result length of " + batchCount + " but got " + lastResult.length);
        } else if (foundError) {
            log.warning("Problem executing batch - at least one result failed in: " + DefaultGroovyMethods.toList(lastResult));
        } else {
            log.fine("Successfully executed batch with " + lastResult.length + " command(s)");
        }
    }

    public void close() throws SQLException {
        delegate.close();
    }
}