org.jberet.support.io.ExcelUserModelItemReader Maven / Gradle / Ivy

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/*
 * Copyright (c) 2014 Red Hat, Inc. and/or its affiliates.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 */

package org.jberet.support.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.jberet.support._private.SupportLogger;
import org.jberet.support._private.SupportMessages;

import jakarta.batch.api.BatchProperty;
import jakarta.batch.api.chunk.ItemReader;
import jakarta.enterprise.context.Dependent;
import jakarta.inject.Inject;
import jakarta.inject.Named;

/**
 * An implementation of {@code jakarta.batch.api.chunk.ItemReader} for reading Excel files. Current implementation is
 * based on Apache POI user model API.
 *
 * @see     ExcelUserModelItemWriter
 * @see     ExcelItemReaderWriterBase
 * @see     ExcelEventItemReader
 * @see     ExcelStreamingItemReader
 * @since   1.1.0
 */
@Named
@Dependent
public class ExcelUserModelItemReader extends ExcelItemReaderWriterBase implements ItemReader {
    /**
     * A positive integer indicating the start position in the input resource. It is optional and defaults to 0
     * (starting from the 1st data item).  If a header row is present, the start point should be after the header row.
     */
    @Inject
    @BatchProperty
    protected int start;

    /**
     * A positive integer indicating the end position in the input resource. It is optional and defaults to
     * {@code Integer.MAX_VALUE}.
     */
    @Inject
    @BatchProperty
    protected int end;

    /**
     * The index (0-based) of the target sheet to read, defaults to 0.
     */
    @Inject
    @BatchProperty
    protected int sheetIndex;

    /**
     * The physical row number of the header.
     */
    @Inject
    @BatchProperty
    protected Integer headerRow;

    protected InputStream inputStream;
    protected FormulaEvaluator formulaEvaluator;
    protected Iterator rowIterator;
    protected int minColumnCount;

    /**
     * Mapping between column label -> header name, e.g, {A : name, B: age}, or {1: name, 2: age} for R1C1 notation.
     * Only applicable when {@link #beanType} is not {@code List}.
     */
    protected Map headerMapping;


    @Override
    public void open(final Serializable checkpoint) throws Exception {
        /**
         * The row number to start reading.  It may be different from the injected field start. During a restart,
         * we would start reading from where it ended during the last run.
         */
        if (this.end == 0) {
            this.end = Integer.MAX_VALUE;
        }
        if (headerRow == null) {
            if (header == null) {
                throw SupportMessages.MESSAGES.invalidReaderWriterProperty(null, null, "header | headerRow");
            }
            headerRow = -1;
        }
        if (start == headerRow) {
            start += 1;
        }

        final int startRowNumber = checkpoint == null ? this.start : (Integer) checkpoint;
        if (startRowNumber < this.start || startRowNumber > this.end
                || startRowNumber < 0 || startRowNumber <= headerRow) {
            throw SupportMessages.MESSAGES.invalidStartPosition(startRowNumber, this.start, this.end);
        }

        inputStream = getInputStream(resource, false);
        initWorkbookAndSheet(startRowNumber);

        if (header != null) {
            minColumnCount = header.length;
        }
    }

    @Override
    public Object readItem() throws Exception {
        if (currentRowNum == this.end) {
            return null;
        }
        Row row;
        while (rowIterator.hasNext()) {
            row = rowIterator.next();
            currentRowNum = row.getRowNum();
            final short lastCellNum = row.getLastCellNum();
            if (lastCellNum == -1) {  // no cell in the current row
                continue;
            }
            final int lastColumn = Math.max(lastCellNum, minColumnCount);
            if (java.util.List.class.isAssignableFrom(beanType)) {
                final List