| /* |
| * 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. |
| */ |
| |
| package org.apache.pdfbox.cos; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.pdfbox.filter.DecodeOptions; |
| import org.apache.pdfbox.filter.DecodeResult; |
| import org.apache.pdfbox.filter.Filter; |
| |
| /** |
| * An InputStream which reads from an encoded COS stream. |
| * |
| * @author John Hewson |
| */ |
| public final class COSInputStream extends FilterInputStream |
| { |
| /** |
| * Creates a new COSInputStream from an encoded input stream. |
| * |
| * @param filters Filters to be applied. |
| * @param parameters Filter parameters. |
| * @param in Encoded input stream. |
| * @return Decoded stream. |
| * @throws IOException If the stream could not be read. |
| */ |
| static COSInputStream create(List<Filter> filters, COSDictionary parameters, InputStream in) |
| throws IOException |
| { |
| return create(filters, parameters, in, DecodeOptions.DEFAULT); |
| } |
| |
| /** |
| * Creates a new COSInputStream from an encoded input stream. |
| * |
| * @param filters Filters to be applied. |
| * @param parameters Filter parameters. |
| * @param in Encoded input stream. |
| * @param options decode options for the encoded stream |
| * @return Decoded stream. |
| * @throws IOException If the stream could not be read. |
| */ |
| static COSInputStream create(List<Filter> filters, COSDictionary parameters, InputStream in, |
| DecodeOptions options) throws IOException |
| { |
| List<DecodeResult> results = new ArrayList<>(); |
| InputStream input = in; |
| if (!filters.isEmpty()) |
| { |
| Set<Filter> filterSet = new HashSet<>(filters); |
| if (filterSet.size() != filters.size()) |
| { |
| throw new IOException("Duplicate"); |
| } |
| ByteArrayOutputStream output = new ByteArrayOutputStream(); |
| // apply filters |
| for (int i = 0; i < filters.size(); i++) |
| { |
| output.reset(); |
| results.add(filters.get(i).decode(input, output, parameters, i, options)); |
| input = new ByteArrayInputStream(output.toByteArray()); |
| } |
| } |
| return new COSInputStream(input, results); |
| } |
| |
| private final List<DecodeResult> decodeResults; |
| |
| /** |
| * Constructor. |
| * |
| * @param input decoded stream |
| * @param decodeResults results of decoding |
| */ |
| private COSInputStream(InputStream input, List<DecodeResult> decodeResults) |
| { |
| super(input); |
| this.decodeResults = decodeResults; |
| } |
| |
| /** |
| * Returns the result of the last filter, for use by repair mechanisms. |
| */ |
| public DecodeResult getDecodeResult() |
| { |
| if (decodeResults.isEmpty()) |
| { |
| return DecodeResult.DEFAULT; |
| } |
| else |
| { |
| return decodeResults.get(decodeResults.size() - 1); |
| } |
| } |
| } |