Ant example source code file (TarResource.java)

This example Ant source code file (TarResource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

buildexception, inputstream, io, ioexception, resource, resource, string, string, tarentry, tarentry, tarinputstream, tarresource, tarresource, unsupportedoperationexception, use

The TarResource.java source code

/*
 *  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.tools.ant.types.resources;

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

import org.apache.tools.ant.Project;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.tar.TarEntry;
import org.apache.tools.tar.TarInputStream;

/**
 * A Resource representation of an entry in a tar archive.
 * @since Ant 1.7
 */
public class TarResource extends ArchiveResource {

    private String userName = "";
    private String groupName = "";
    private int    uid;
    private int    gid;

    /**
     * Default constructor.
     */
    public TarResource() {
    }

    /**
     * Construct a TarResource representing the specified
     * entry in the specified archive.
     * @param a the archive as File.
     * @param e the TarEntry.
     */
    public TarResource(File a, TarEntry e) {
        super(a, true);
        setEntry(e);
    }

    /**
     * Construct a TarResource representing the specified
     * entry in the specified archive.
     * @param a the archive as Resource.
     * @param e the TarEntry.
     */
    public TarResource(Resource a, TarEntry e) {
        super(a, true);
        setEntry(e);
    }

    /**
     * Return an InputStream for reading the contents of this Resource.
     * @return an InputStream object.
     * @throws IOException if the tar file cannot be opened,
     *         or the entry cannot be read.
     */
    public InputStream getInputStream() throws IOException {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getInputStream();
        }
        Resource archive = getArchive();
        final TarInputStream i = new TarInputStream(archive.getInputStream());
        TarEntry te = null;
        while ((te = i.getNextEntry()) != null) {
            if (te.getName().equals(getName())) {
                return i;
            }
        }

        FileUtils.close(i);
        throw new BuildException("no entry " + getName() + " in "
                                 + getArchive());
    }

    /**
     * Get an OutputStream for the Resource.
     * @return an OutputStream to which content can be written.
     * @throws IOException if unable to provide the content of this
     *         Resource as a stream.
     * @throws UnsupportedOperationException if OutputStreams are not
     *         supported for this Resource type.
     */
    public OutputStream getOutputStream() throws IOException {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getOutputStream();
        }
        throw new UnsupportedOperationException(
            "Use the tar task for tar output.");
    }

    /**
     * @return the user name for the tar entry
     */
    public String getUserName() {
        if (isReference()) {
            return ((TarResource) getCheckedRef()).getUserName();
        }
        return userName;
    }

    /**
     * @return the group name for the tar entry
     */
    public String getGroup() {
        if (isReference()) {
            return ((TarResource) getCheckedRef()).getGroup();
        }
        return groupName;
    }

    /**
     * @return the uid for the tar entry
     */
    public int getUid() {
        if (isReference()) {
            return ((TarResource) getCheckedRef()).getUid();
        }
        return uid;
    }

    /**
     * @return the uid for the tar entry
     */
    public int getGid() {
        if (isReference()) {
            return ((TarResource) getCheckedRef()).getGid();
        }
        return uid;
    }

    /**
     * fetches information from the named entry inside the archive.
     */
    protected void fetchEntry() {
        Resource archive = getArchive();
        TarInputStream i = null;
        try {
            i = new TarInputStream(archive.getInputStream());
            TarEntry te = null;
            while ((te = i.getNextEntry()) != null) {
                if (te.getName().equals(getName())) {
                    setEntry(te);
                    return;
                }
            }
        } catch (IOException e) {
            log(e.getMessage(), Project.MSG_DEBUG);
            throw new BuildException(e);
        } finally {
            if (i != null) {
                FileUtils.close(i);
            }
        }
        setEntry(null);
    }

    private void setEntry(TarEntry e) {
        if (e == null) {
            setExists(false);
            return;
        }
        setName(e.getName());
        setExists(true);
        setLastModified(e.getModTime().getTime());
        setDirectory(e.isDirectory());
        setSize(e.getSize());
        setMode(e.getMode());
        userName = e.getUserName();
        groupName = e.getGroupName();
        uid = e.getUserId();
        gid = e.getGroupId();
    }

}