org.github.evenjn.zip.ZipDecoderBlueprint Maven / Gradle / Ivy

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Functions to encode and decode.
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/**
 *
 * Copyright 2017 Marco Trevisan
 *
 * 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 org.github.evenjn.zip;

import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;
import org.github.evenjn.lang.Rook;
import org.github.evenjn.yarn.Cursor;
import org.github.evenjn.yarn.CursorRingMap;
import org.github.evenjn.yarn.EndOfCursorException;

public class ZipDecoderBlueprint {

	public CursorRingMap build( ) {
		return ZipDecoderBlueprint::decode;
	}

	private static Cursor decode(
			Rook rook,
			InputStream is ) {
		try {

			final ZipArchiveInputStream zais = rook.hook(
					(ZipArchiveInputStream) new ArchiveStreamFactory( )
							.createArchiveInputStream( "zip", is ) );

			return new Cursor( ) {

				@Override
				public ZipEntry next( )
						throws EndOfCursorException {
					ZipEntry result = new ZipEntry( );
					try {
						result.entry = (ZipArchiveEntry) zais.getNextZipEntry( );
						if ( result.entry == null ) {
							throw EndOfCursorException.neo( );
						}

						final long size = result.entry.getSize( );

						result.is = new InputStream( ) {

							long left = size;

							@Override
							public int read( )
									throws IOException {
								if ( left == 0 ) {
									return -1;
								}
								int result = zais.read( );
								left = left - 1;
								return result;
							}
						};
					}
					catch ( IOException t ) {
						throw new RuntimeException( t );
					}
					return result;
				}
			};
		}
		catch ( ArchiveException t ) {
			throw new RuntimeException( t );
		}
	}
}