org.apache.commons.compress.archivers.ar.ArArchiveOutputStream Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of commons-compress Show documentation
Apache Commons Compress defines an API for working with compression and archive formats. These include bzip2, gzip, pack200, LZMA, XZ, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.
There is a newer version: 1.27.1
Show newest version
/*
 * 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.commons.compress.archivers.ar;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.ArchiveOutputStream;
import org.apache.commons.compress.utils.ArchiveUtils;

/**
 * Implements the "ar" archive format as an output stream.
 * 
 * @NotThreadSafe
 */
public class ArArchiveOutputStream extends ArchiveOutputStream {
    /** Fail if a long file name is required in the archive. */
    public static final int LONGFILE_ERROR = 0;

    /** BSD ar extensions are used to store long file names in the archive. */
    public static final int LONGFILE_BSD = 1;

    private final OutputStream out;
    private long entryOffset = 0;
    private ArArchiveEntry prevEntry;
    private boolean haveUnclosedEntry = false;
    private int longFileMode = LONGFILE_ERROR;

    /** indicates if this archive is finished */
    private boolean finished = false;

    public ArArchiveOutputStream( final OutputStream pOut ) {
        this.out = pOut;
    }

    /**
     * Set the long file mode.
     * This can be LONGFILE_ERROR(0) or LONGFILE_BSD(1).
     * This specifies the treatment of long file names (names >= 16).
     * Default is LONGFILE_ERROR.
     * @param longFileMode the mode to use
     * @since 1.3
     */
    public void setLongFileMode(int longFileMode) {
        this.longFileMode = longFileMode;
    }

    private long writeArchiveHeader() throws IOException {
        byte [] header = ArchiveUtils.toAsciiBytes(ArArchiveEntry.HEADER);
        out.write(header);
        return header.length;
    }

    @Override
    public void closeArchiveEntry() throws IOException {
        if(finished) {
            throw new IOException("Stream has already been finished");
        }
        if (prevEntry == null || !haveUnclosedEntry){
            throw new IOException("No current entry to close");
        }
        if (entryOffset % 2 != 0) {
            out.write('\n'); // Pad byte
        }
        haveUnclosedEntry = false;
    }

    @Override
    public void putArchiveEntry( final ArchiveEntry pEntry ) throws IOException {
        if(finished) {
            throw new IOException("Stream has already been finished");
        }

        ArArchiveEntry pArEntry = (ArArchiveEntry)pEntry;
        if (prevEntry == null) {
            writeArchiveHeader();
        } else {
            if (prevEntry.getLength() != entryOffset) {
                throw new IOException("length does not match entry (" + prevEntry.getLength() + " != " + entryOffset);
            }

            if (haveUnclosedEntry) {
                closeArchiveEntry();
            }
        }

        prevEntry = pArEntry;

        writeEntryHeader(pArEntry);

        entryOffset = 0;
        haveUnclosedEntry = true;
    }

    private long fill( final long pOffset, final long pNewOffset, final char pFill ) throws IOException { 
        final long diff = pNewOffset - pOffset;

        if (diff > 0) {
            for (int i = 0; i < diff; i++) {
                write(pFill);
            }
        }

        return pNewOffset;
    }

    private long write( final String data ) throws IOException {
        final byte[] bytes = data.getBytes("ascii");
        write(bytes);
        return bytes.length;
    }

    private long writeEntryHeader( final ArArchiveEntry pEntry ) throws IOException {

        long offset = 0;
        boolean mustAppendName = false;

        final String n = pEntry.getName();
        if (LONGFILE_ERROR == longFileMode && n.length() > 16) {
            throw new IOException("filename too long, > 16 chars: "+n);
        }
        if (LONGFILE_BSD == longFileMode && 
            (n.length() > 16 || n.indexOf(" ") > -1)) {
            mustAppendName = true;
            offset += write(ArArchiveInputStream.BSD_LONGNAME_PREFIX
                            + String.valueOf(n.length()));
        } else {
            offset += write(n);
        }

        offset = fill(offset, 16, ' ');
        final String m = "" + pEntry.getLastModified();
        if (m.length() > 12) {
            throw new IOException("modified too long");
        }
        offset += write(m);

        offset = fill(offset, 28, ' ');
        final String u = "" + pEntry.getUserId();
        if (u.length() > 6) {
            throw new IOException("userid too long");
        }
        offset += write(u);

        offset = fill(offset, 34, ' ');
        final String g = "" + pEntry.getGroupId();
        if (g.length() > 6) {
            throw new IOException("groupid too long");
        }
        offset += write(g);

        offset = fill(offset, 40, ' ');
        final String fm = "" + Integer.toString(pEntry.getMode(), 8);
        if (fm.length() > 8) {
            throw new IOException("filemode too long");
        }
        offset += write(fm);

        offset = fill(offset, 48, ' ');
        final String s =
            String.valueOf(pEntry.getLength()
                           + (mustAppendName ? n.length() : 0));
        if (s.length() > 10) {
            throw new IOException("size too long");
        }
        offset += write(s);

        offset = fill(offset, 58, ' ');

        offset += write(ArArchiveEntry.TRAILER);

        if (mustAppendName) {
            offset += write(n);
        }

        return offset;
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        out.write(b, off, len);
        count(len);
        entryOffset += len;
    }

    /**
     * Calls finish if necessary, and then closes the OutputStream
     */
    @Override
    public void close() throws IOException {
        if(!finished) {
            finish();
        }
        out.close();
        prevEntry = null;
    }

    @Override
    public ArchiveEntry createArchiveEntry(File inputFile, String entryName)
            throws IOException {
        if(finished) {
            throw new IOException("Stream has already been finished");
        }
        return new ArArchiveEntry(inputFile, entryName);
    }

    @Override
    public void finish() throws IOException {
        if(haveUnclosedEntry) {
            throw new IOException("This archive contains unclosed entries.");
        } else if(finished) {
            throw new IOException("This archive has already been finished");
        }
        finished = true;
    }
}