org.eclipse.jetty.util.resource.URLResource Maven / Gradle / Ivy

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// 
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// 
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// 
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// 
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
// 
package org.eclipse.jetty.util.resource;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.channels.ReadableByteChannel;
import org.eclipse.jetty.util.URIUtil;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;

/**
 *  URL resource class.
 *
 * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
 */
@Deprecated(since = "2021-05-27")
public class URLResource extends Resource {

    private static final Logger LOG = Log.getLogger(URLResource.class);

    protected final URL _url;

    protected final String _urlString;

    protected URLConnection _connection;

    protected InputStream _in = null;

    transient boolean _useCaches = Resource.__defaultUseCaches;

    protected URLResource(URL url, URLConnection connection) {
        _url = url;
        _urlString = _url.toExternalForm();
        _connection = connection;
    }

    protected URLResource(URL url, URLConnection connection, boolean useCaches) {
        this(url, connection);
        _useCaches = useCaches;
    }

    protected synchronized boolean checkConnection() {
        if (_connection == null) {
            try {
                _connection = _url.openConnection();
                _connection.setUseCaches(_useCaches);
            } catch (IOException e) {
                LOG.ignore(e);
            }
        }
        return _connection != null;
    }

    /**
     * Release any resources held by the resource.
     */
    @Override
    public synchronized void close() {
        if (_in != null) {
            try {
                _in.close();
            } catch (IOException e) {
                LOG.ignore(e);
            }
            _in = null;
        }
        if (_connection != null)
            _connection = null;
    }

    /**
     * Returns true if the represented resource exists.
     */
    @Override
    public boolean exists() {
        try {
            synchronized (this) {
                if (checkConnection() && _in == null)
                    _in = _connection.getInputStream();
            }
        } catch (IOException e) {
            LOG.ignore(e);
        }
        return _in != null;
    }

    /**
     * Returns true if the represented resource is a container/directory.
     * If the resource is not a file, resources ending with "/" are
     * considered directories.
     */
    @Override
    public boolean isDirectory() {
        return exists() && _urlString.endsWith("/");
    }

    /**
     * Returns the last modified time
     */
    @Override
    public long lastModified() {
        if (checkConnection())
            return _connection.getLastModified();
        return -1;
    }

    /**
     * Return the length of the resource
     */
    @Override
    public long length() {
        if (checkConnection())
            return _connection.getContentLength();
        return -1;
    }

    /**
     * Returns a URL representing the given resource
     */
    @Override
    public URL getURL() {
        return _url;
    }

    /**
     * Returns an File representing the given resource or NULL if this
     * is not possible.
     */
    @Override
    public File getFile() throws IOException {
        return null;
    }

    /**
     * Returns the name of the resource
     */
    @Override
    public String getName() {
        return _url.toExternalForm();
    }

    /**
     * Returns an input stream to the resource. The underlying
     * url connection will be nulled out to prevent re-use.
     */
    @Override
    public synchronized InputStream getInputStream() throws java.io.IOException {
        // backwards compatibility
        return getInputStream(true);
    }

    /**
     * Returns an input stream to the resource, optionally nulling
     * out the underlying url connection. If the connection is not
     * nulled out, a subsequent call to getInputStream() may return
     * an existing and already in-use input stream - this depends on
     * the url protocol. Eg JarURLConnection does not reuse inputstreams.
     *
     * @param resetConnection if true the connection field is set to null
     * @return the inputstream for this resource
     * @throws IOException if unable to open the input stream
     */
    protected synchronized InputStream getInputStream(boolean resetConnection) throws IOException {
        if (!checkConnection())
            throw new IOException("Invalid resource");
        try {
            if (_in != null) {
                InputStream in = _in;
                _in = null;
                return in;
            }
            return _connection.getInputStream();
        } finally {
            if (resetConnection) {
                _connection = null;
                if (LOG.isDebugEnabled())
                    LOG.debug("Connection nulled");
            }
        }
    }

    @Override
    public ReadableByteChannel getReadableByteChannel() throws IOException {
        return null;
    }

    /**
     * Deletes the given resource
     */
    @Override
    public boolean delete() throws SecurityException {
        throw new SecurityException("Delete not supported");
    }

    /**
     * Rename the given resource
     */
    @Override
    public boolean renameTo(Resource dest) throws SecurityException {
        throw new SecurityException("RenameTo not supported");
    }

    /**
     * Returns a list of resource names contained in the given resource
     */
    @Override
    public String[] list() {
        return null;
    }

    /**
     * Returns the resource contained inside the current resource with the
     * given name
     */
    @Override
    public Resource addPath(String path) throws IOException {
        // Check that the path is within the root,
        // but use the original path to create the
        // resource, to preserve aliasing.
        if (URIUtil.canonicalPath(path) == null)
            throw new MalformedURLException(path);
        return newResource(URIUtil.addEncodedPaths(_url.toExternalForm(), URIUtil.encodePath(path)), _useCaches);
    }

    @Override
    public String toString() {
        return _urlString;
    }

    @Override
    public int hashCode() {
        return _urlString.hashCode();
    }

    @Override
    public boolean equals(Object o) {
        return o instanceof URLResource && _urlString.equals(((URLResource) o)._urlString);
    }

    public boolean getUseCaches() {
        return _useCaches;
    }

    @Override
    public boolean isContainedIn(Resource containingResource) throws MalformedURLException {
        return false;
    }
}