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	/*
	* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.net;

	import java.io.IOException;
	import java.util.jar.JarFile;
	import java.util.jar.JarEntry;
	import java.util.jar.Attributes;
	import java.util.jar.Manifest;
	import java.security.Permission;
	import sun.net.www.ParseUtil;

	/**
	* A URL Connection to a Java ARchive (JAR) file or an entry in a JAR
	* file.
	*
	* <p>The syntax of a JAR URL is:
	*
	* <pre>
	* jar:<url>!/{entry}
	* </pre>
	*
	* <p>for example:
	*
	* <p>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
	*
	* <p>Jar URLs should be used to refer to a JAR file or entries in
	* a JAR file. The example above is a JAR URL which refers to a JAR
	* entry. If the entry name is omitted, the URL refers to the whole
	* JAR file:
	*
	* {@code jar:http://www.foo.com/bar/baz.jar!/}
	*
	* <p>Users should cast the generic URLConnection to a
	* JarURLConnection when they know that the URL they created is a JAR
	* URL, and they need JAR-specific functionality. For example:
	*
	* <pre>
	* URL url = new URL("jar:file:/home/duke/duke.jar!/");
	* JarURLConnection jarConnection = (JarURLConnection)url.openConnection();
	* Manifest manifest = jarConnection.getManifest();
	* </pre>
	*
	* <p>JarURLConnection instances can only be used to read from JAR files.
	* It is not possible to get a {@link java.io.OutputStream} to modify or write
	* to the underlying JAR file using this class.
	* <p>Examples:
	*
	* <dl>
	*
	* <dt>A Jar entry
	* <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
	*
	* <dt>A Jar file
	* <dd>{@code jar:http://www.foo.com/bar/baz.jar!/}
	*
	* <dt>A Jar directory
	* <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/}
	*
	* </dl>
	*
	* <p>{@code !/} is referred to as the <em>separator</em>.
	*
	* <p>When constructing a JAR url via {@code new URL(context, spec)},
	* the following rules apply:
	*
	* <ul>
	*
	* <li>if there is no context URL and the specification passed to the
	* URL constructor doesn't contain a separator, the URL is considered
	* to refer to a JarFile.
	*
	* <li>if there is a context URL, the context URL is assumed to refer
	* to a JAR file or a Jar directory.
	*
	* <li>if the specification begins with a '/', the Jar directory is
	* ignored, and the spec is considered to be at the root of the Jar
	* file.
	*
	* <p>Examples:
	*
	* <dl>
	*
	* <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/</b>,
	* spec:<b>baz/entry.txt</b>
	*
	* <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
	*
	* <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
	* spec:<b>entry.txt</b>
	*
	* <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
	*
	* <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
	* spec:<b>/entry.txt</b>
	*
	* <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/entry.txt</b>
	*
	* </dl>
	*
	* </ul>
	*
	* @see java.net.URL
	* @see java.net.URLConnection
	*
	* @see java.util.jar.JarFile
	* @see java.util.jar.JarInputStream
	* @see java.util.jar.Manifest
	* @see java.util.zip.ZipEntry
	*
	* @author Benjamin Renaud
	* @since 1.2
	*/
	public abstract class JarURLConnection extends URLConnection {

	private URL jarFileURL;
	private String entryName;

	/**
	* The connection to the JAR file URL, if the connection has been
	* initiated. This should be set by connect.
	*/
	protected URLConnection jarFileURLConnection;

	/**
	* Creates the new JarURLConnection to the specified URL.
	* @param url the URL
	* @throws MalformedURLException if no legal protocol
	* could be found in a specification string or the
	* string could not be parsed.
	*/

	protected JarURLConnection(URL url) throws MalformedURLException {
	super(url);
	parseSpecs(url);
	}

	/* get the specs for a given url out of the cache, and compute and
	* cache them if they're not there.
	*/
	private void parseSpecs(URL url) throws MalformedURLException {
	String spec = url.getFile();

	int separator = spec.indexOf("!/");
	/*
	* REMIND: we don't handle nested JAR URLs
	*/
	if (separator == -1) {
	throw new MalformedURLException("no !/ found in url spec:" + spec);
	}

	jarFileURL = new URL(spec.substring(0, separator++));
	/*
	* The url argument may have had a runtime fragment appended, so
	* we need to add a runtime fragment to the jarFileURL to enable
	* runtime versioning when the underlying jar file is opened.
	*/
	if ("runtime".equals(url.getRef())) {
	jarFileURL = new URL(jarFileURL, "#runtime");
	}
	entryName = null;

	/* if ! is the last letter of the innerURL, entryName is null */
	if (++separator != spec.length()) {
	entryName = spec.substring(separator, spec.length());
	entryName = ParseUtil.decode (entryName);
	}
	}

	/**
	* Returns the URL for the Jar file for this connection.
	*
	* @return the URL for the Jar file for this connection.
	*/
	public URL getJarFileURL() {
	return jarFileURL;
	}

	/**
	* Return the entry name for this connection. This method
	* returns null if the JAR file URL corresponding to this
	* connection points to a JAR file and not a JAR file entry.
	*
	* @return the entry name for this connection, if any.
	*/
	public String getEntryName() {
	return entryName;
	}

	/**
	* Return the JAR file for this connection.
	*
	* @return the JAR file for this connection. If the connection is
	* a connection to an entry of a JAR file, the JAR file object is
	* returned
	*
	* @throws IOException if an IOException occurs while trying to
	* connect to the JAR file for this connection.
	*
	* @see #connect
	*/
	public abstract JarFile getJarFile() throws IOException;

	/**
	* Returns the Manifest for this connection, or null if none.
	*
	* @return the manifest object corresponding to the JAR file object
	* for this connection.
	*
	* @throws IOException if getting the JAR file for this
	* connection causes an IOException to be thrown.
	*
	* @see #getJarFile
	*/
	public Manifest getManifest() throws IOException {
	return getJarFile().getManifest();
	}

	/**
	* Return the JAR entry object for this connection, if any. This
	* method returns null if the JAR file URL corresponding to this
	* connection points to a JAR file and not a JAR file entry.
	*
	* @return the JAR entry object for this connection, or null if
	* the JAR URL for this connection points to a JAR file.
	*
	* @throws IOException if getting the JAR file for this
	* connection causes an IOException to be thrown.
	*
	* @see #getJarFile
	* @see #getJarEntry
	*/
	public JarEntry getJarEntry() throws IOException {
	return entryName == null ? null : getJarFile().getJarEntry(entryName);
	}

	/**
	* Return the Attributes object for this connection if the URL
	* for it points to a JAR file entry, null otherwise.
	*
	* @return the Attributes object for this connection if the URL
	* for it points to a JAR file entry, null otherwise.
	*
	* @throws IOException if getting the JAR entry causes an
	* IOException to be thrown.
	*
	* @see #getJarEntry
	*/
	public Attributes getAttributes() throws IOException {
	JarEntry e = getJarEntry();
	return e != null ? e.getAttributes() : null;
	}

	/**
	* Returns the main Attributes for the JAR file for this
	* connection.
	*
	* @return the main Attributes for the JAR file for this
	* connection.
	*
	* @throws IOException if getting the manifest causes an
	* IOException to be thrown.
	*
	* @see #getJarFile
	* @see #getManifest
	*/
	public Attributes getMainAttributes() throws IOException {
	Manifest man = getManifest();
	return man != null ? man.getMainAttributes() : null;
	}

	/**
	* Returns the Certificate objects for this connection if the URL
	* for it points to a JAR file entry, null otherwise. This method
	* can only be called once
	* the connection has been completely verified by reading
	* from the input stream until the end of the stream has been
	* reached. Otherwise, this method will return {@code null}
	*
	* @return the Certificate object for this connection if the URL
	* for it points to a JAR file entry, null otherwise.
	*
	* @throws IOException if getting the JAR entry causes an
	* IOException to be thrown.
	*
	* @see #getJarEntry
	*/
	public java.security.cert.Certificate[] getCertificates()
	throws IOException
	{
	JarEntry e = getJarEntry();
	return e != null ? e.getCertificates() : null;
	}
	}

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