com.codecrate.shard.transfer.excel.ExcelObjectImporter.java Source code

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Here is the source code for com.codecrate.shard.transfer.excel.ExcelObjectImporter.java

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/*
 * Copyright 2004 codecrate consulting
 *
 *  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.codecrate.shard.transfer.excel;

import java.io.File;
import java.io.FileInputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

import com.codecrate.shard.transfer.ObjectImporter;
import com.codecrate.shard.transfer.progress.ProgressMonitor;

public class ExcelObjectImporter implements ObjectImporter {
    private static final String EXCEL_FILE_EXTENSION = "xls";
    private static final Log LOG = LogFactory.getLog(ExcelObjectImporter.class);
    private final ExcelRowHandler rowHandler;

    public ExcelObjectImporter(ExcelObjectImporter.ExcelRowHandler rowHandler) {
        this.rowHandler = rowHandler;
    }

    public Collection getSupportedFileExtensions() {
        return Collections.singletonList(EXCEL_FILE_EXTENSION);
    }

    public boolean isDirectoryImportSupported() {
        return false;
    }

    public Collection importObjects(File file, ProgressMonitor progress) {
        Collection results = new ArrayList();

        try {
            POIFSFileSystem poifs = new POIFSFileSystem(new FileInputStream(file));

            HSSFWorkbook workbook = new HSSFWorkbook(poifs);
            HSSFSheet sheet = workbook.getSheetAt(0);

            int firstRow = sheet.getFirstRowNum() + 1;
            int lastRow = sheet.getLastRowNum();

            progress.startTask("Import objects from " + file.getName(), lastRow - firstRow);
            for (int currentRow = firstRow; currentRow <= lastRow; currentRow++) {
                HSSFRow row = sheet.getRow(currentRow);

                try {
                    Object result = rowHandler.handleRow(row);
                    results.add(result);
                } catch (Exception e) {
                    LOG.error("Error importing row: " + currentRow, e);
                }

                progress.completeUnitOfWork();
            }
        } catch (Exception e) {
            LOG.error("Error importing file: " + file, e);
        }

        progress.finish();

        return results;
    }

    public interface ExcelRowHandler {
        Object handleRow(HSSFRow row);
    }
}