55 lines
1.8 KiB
Java
55 lines
1.8 KiB
Java
// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
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//
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// SPDX-License-Identifier: Apache-2.0
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package org.pgpainless.decryption_verification.cleartext_signatures;
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import java.io.File;
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import java.io.FileInputStream;
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import java.io.FileOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.OutputStream;
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/**
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* Implementation of the {@link MultiPassStrategy}.
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* When processing signed data the first time, the data is being written out into a file.
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* For the second pass, that file is being read again.
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*
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* This strategy is recommended when larger amounts of data need to be processed.
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* For smaller files, {@link InMemoryMultiPassStrategy} yields higher efficiency.
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*/
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public class WriteToFileMultiPassStrategy implements MultiPassStrategy {
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private final File file;
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/**
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* Create a {@link MultiPassStrategy} which writes data to a file.
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* Note that {@link #getMessageOutputStream()} will create the file if necessary.
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*
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* @param file file to write the data to and read from
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*/
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public WriteToFileMultiPassStrategy(File file) {
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this.file = file;
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}
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@Override
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public OutputStream getMessageOutputStream() throws IOException {
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if (!file.exists()) {
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boolean created = file.createNewFile();
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if (!created) {
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throw new IOException("New file '" + file.getAbsolutePath() + "' was not created.");
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}
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}
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return new FileOutputStream(file);
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}
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@Override
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public InputStream getMessageInputStream() throws IOException {
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if (!file.exists()) {
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throw new IOException("File '" + file.getAbsolutePath() + "' does no longer exist.");
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}
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return new FileInputStream(file);
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}
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}
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