examples/src/main/java/org/apache/poi/examples/xssf/usermodel/LoadPasswordProtectedXlsx.java

/*
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 *    Licensed to 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.
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package org.apache.poi.examples.xssf.usermodel;

import java.io.FileInputStream;
import java.io.InputStream;

import org.apache.poi.examples.util.TempFileUtils;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.poifs.crypt.Decryptor;
import org.apache.poi.poifs.crypt.EncryptionInfo;
import org.apache.poi.poifs.crypt.temp.AesZipFileZipEntrySource;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/**
 * An example that loads a password protected workbook and counts the sheets.
 * <p><ul>
 * <li>The example demonstrates that all temp files are removed.
 * <li><code>AesZipFileZipEntrySource</code> is used to ensure that temp files are encrypted.
 * </ul></p>
 */
@SuppressWarnings({"java:S106","java:S4823","java:S1192"})
public final class LoadPasswordProtectedXlsx {

    private LoadPasswordProtectedXlsx() {}

    public interface EncryptionHandler {
        void handle(final InputStream inputStream) throws Exception;
    }

    public static void main(String[] args) throws Exception {
        execute(args, LoadPasswordProtectedXlsx::printSheetCount);
    }

    public static void execute(String[] args, EncryptionHandler handler) throws Exception {
        if(args.length != 2) {
            throw new IllegalArgumentException("Expected 2 params: filename and password");
        }
        TempFileUtils.checkTempFiles();
        String filename = args[0];
        String password = args[1];
        try (FileInputStream fis = new FileInputStream(filename);
             POIFSFileSystem fs = new POIFSFileSystem(fis)) {
            EncryptionInfo info = new EncryptionInfo(fs);
            Decryptor d = Decryptor.getInstance(info);
            if (!d.verifyPassword(password)) {
                throw new RuntimeException("incorrect password");
            }
            try (InputStream unencryptedStream = d.getDataStream(fs)) {
                handler.handle(unencryptedStream);
            }
        }
        TempFileUtils.checkTempFiles();
    }


    private static void printSheetCount(final InputStream inputStream) throws Exception {
        try (AesZipFileZipEntrySource source = AesZipFileZipEntrySource.createZipEntrySource(inputStream);
             OPCPackage pkg = OPCPackage.open(source);
             XSSFWorkbook workbook = new XSSFWorkbook(pkg)) {
            System.out.println("sheet count: " + workbook.getNumberOfSheets());
        }
    }

}