https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2020, 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 sun.net.www.protocol.jar;

import java.io.InputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.BufferedInputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.MalformedURLException;
import java.net.UnknownServiceException;
import java.util.Enumeration;
import java.util.Map;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.security.Permission;


Author:Benjamin Renaud
Since:1.2
/**
 * @author Benjamin Renaud
 * @since 1.2
 */
public class JarURLConnection extends java.net.JarURLConnection {

    private static final boolean debug = false;

    /* the Jar file factory. It handles both retrieval and caching.
     */
    private static final JarFileFactory factory = JarFileFactory.getInstance();

    /* the url for the Jar file */
    private URL jarFileURL;

    /* the permission to get this JAR file. This is the actual, ultimate,
     * permission, returned by the jar file factory.
     */
    private Permission permission;

    /* the url connection for the JAR file */
    private URLConnection jarFileURLConnection;

    /* the entry name, if any */
    private String entryName;

    /* the JarEntry */
    private JarEntry jarEntry;

    /* the jar file corresponding to this connection */
    private JarFile jarFile;

    /* the content type for this connection */
    private String contentType;

    public JarURLConnection(URL url, Handler handler)
    throws MalformedURLException, IOException {
        super(url);

        jarFileURL = getJarFileURL();
        jarFileURLConnection = jarFileURL.openConnection();
        // whether, or not, the embedded URL should use the cache will depend
        // on this instance's cache value
        jarFileURLConnection.setUseCaches(useCaches);
        entryName = getEntryName();
    }

    public JarFile getJarFile() throws IOException {
        connect();
        return jarFile;
    }

    public JarEntry getJarEntry() throws IOException {
        connect();
        return jarEntry;
    }

    public Permission getPermission() throws IOException {
        return jarFileURLConnection.getPermission();
    }

    class JarURLInputStream extends java.io.FilterInputStream {
        JarURLInputStream (InputStream src) {
            super (src);
        }
        public void close () throws IOException {
            try {
                super.close();
            } finally {
                if (!getUseCaches()) {
                    jarFile.close();
                }
            }
        }
    }



    public void connect() throws IOException {
        if (!connected) {
            /* the factory call will do the security checks */
            jarFile = factory.get(getJarFileURL(), getUseCaches());

            /* we also ask the factory the permission that was required
             * to get the jarFile, and set it as our permission.
             */
            if (getUseCaches()) {
                boolean oldUseCaches = jarFileURLConnection.getUseCaches();
                jarFileURLConnection = factory.getConnection(jarFile);
                jarFileURLConnection.setUseCaches(oldUseCaches);
            }

            if ((entryName != null)) {
                jarEntry = (JarEntry)jarFile.getEntry(entryName);
                if (jarEntry == null) {
                    try {
                        if (!getUseCaches()) {
                            jarFile.close();
                        }
                    } catch (Exception e) {
                    }
                    throw new FileNotFoundException("JAR entry " + entryName +
                                                    " not found in " +
                                                    jarFile.getName());
                }
            }
            connected = true;
        }
    }

    public InputStream getInputStream() throws IOException {
        connect();

        InputStream result = null;

        if (entryName == null) {
            throw new IOException("no entry name specified");
        } else {
            if (jarEntry == null) {
                throw new FileNotFoundException("JAR entry " + entryName +
                                                " not found in " +
                                                jarFile.getName());
            }
            result = new JarURLInputStream (jarFile.getInputStream(jarEntry));
        }
        return result;
    }

    public int getContentLength() {
        long result = getContentLengthLong();
        if (result > Integer.MAX_VALUE)
            return -1;
        return (int) result;
    }

    public long getContentLengthLong() {
        long result = -1;
        try {
            connect();
            if (jarEntry == null) {
                /* if the URL referes to an archive */
                result = jarFileURLConnection.getContentLengthLong();
            } else {
                /* if the URL referes to an archive entry */
                result = getJarEntry().getSize();
            }
        } catch (IOException e) {
        }
        return result;
    }

    public Object getContent() throws IOException {
        Object result = null;

        connect();
        if (entryName == null) {
            result = jarFile;
        } else {
            result = super.getContent();
        }
        return result;
    }

    public String getContentType() {
        if (contentType == null) {
            if (entryName == null) {
                contentType = "x-java/jar";
            } else {
                try {
                    connect();
                    InputStream in = jarFile.getInputStream(jarEntry);
                    contentType = guessContentTypeFromStream(
                                        new BufferedInputStream(in));
                    in.close();
                } catch (IOException e) {
                    // don't do anything
                }
            }
            if (contentType == null) {
                contentType = guessContentTypeFromName(entryName);
            }
            if (contentType == null) {
                contentType = "content/unknown";
            }
        }
        return contentType;
    }

    public String getHeaderField(String name) {
        return jarFileURLConnection.getHeaderField(name);
    }

    
Sets the general request property.

Params:
  • key –     the keyword by which the request is known
                 (e.g., "accept").
  • value –   the value associated with it.
/**
     * Sets the general request property.
     *
     * @param   key     the keyword by which the request is known
     *                  (e.g., "<code>accept</code>").
     * @param   value   the value associated with it.
     */
    public void setRequestProperty(String key, String value) {
        jarFileURLConnection.setRequestProperty(key, value);
    }

    
Returns the value of the named general request property for this
connection.

Returns: the value of the named general request property for this
          connection.
/**
     * Returns the value of the named general request property for this
     * connection.
     *
     * @return  the value of the named general request property for this
     *           connection.
     */
    public String getRequestProperty(String key) {
        return jarFileURLConnection.getRequestProperty(key);
    }

    
Adds a general request property specified by a
key-value pair.  This method will not overwrite
existing values associated with the same key.

Params:
  • key –     the keyword by which the request is known
                 (e.g., "accept").
  • value –   the value associated with it.
/**
     * Adds a general request property specified by a
     * key-value pair.  This method will not overwrite
     * existing values associated with the same key.
     *
     * @param   key     the keyword by which the request is known
     *                  (e.g., "<code>accept</code>").
     * @param   value   the value associated with it.
     */
    public void addRequestProperty(String key, String value) {
        jarFileURLConnection.addRequestProperty(key, value);
    }

    
Returns an unmodifiable Map of general request
properties for this connection. The Map keys
are Strings that represent the request-header
field names. Each Map value is a unmodifiable List
of Strings that represents the corresponding
field values.

Returns: a Map of the general request properties for this connection.
/**
     * Returns an unmodifiable Map of general request
     * properties for this connection. The Map keys
     * are Strings that represent the request-header
     * field names. Each Map value is a unmodifiable List
     * of Strings that represents the corresponding
     * field values.
     *
     * @return  a Map of the general request properties for this connection.
     */
    public Map<String,List<String>> getRequestProperties() {
        return jarFileURLConnection.getRequestProperties();
    }

    
Set the value of the allowUserInteraction field of
this URLConnection.

Params:
  • allowuserinteraction –   the new value.
See Also:
  • URLConnection.allowUserInteraction
/**
     * Set the value of the <code>allowUserInteraction</code> field of
     * this <code>URLConnection</code>.
     *
     * @param   allowuserinteraction   the new value.
     * @see     java.net.URLConnection#allowUserInteraction
     */
    public void setAllowUserInteraction(boolean allowuserinteraction) {
        jarFileURLConnection.setAllowUserInteraction(allowuserinteraction);
    }

    
Returns the value of the allowUserInteraction field for
this object.

See Also:
  • URLConnection.allowUserInteraction
Returns: the value of the allowUserInteraction field for
         this object.
/**
     * Returns the value of the <code>allowUserInteraction</code> field for
     * this object.
     *
     * @return  the value of the <code>allowUserInteraction</code> field for
     *          this object.
     * @see     java.net.URLConnection#allowUserInteraction
     */
    public boolean getAllowUserInteraction() {
        return jarFileURLConnection.getAllowUserInteraction();
    }

    /*
     * cache control
     */

    
Sets the value of the useCaches field of this
URLConnection to the specified value.


Some protocols do caching of documents.  Occasionally, it is important
to be able to "tunnel through" and ignore the caches (e.g., the
"reload" button in a browser).  If the UseCaches flag on a connection
is true, the connection is allowed to use whatever caches it can.
 If false, caches are to be ignored.
 The default value comes from DefaultUseCaches, which defaults to
true.

See Also:
  • useCaches.useCaches
/**
     * Sets the value of the <code>useCaches</code> field of this
     * <code>URLConnection</code> to the specified value.
     * <p>
     * Some protocols do caching of documents.  Occasionally, it is important
     * to be able to "tunnel through" and ignore the caches (e.g., the
     * "reload" button in a browser).  If the UseCaches flag on a connection
     * is true, the connection is allowed to use whatever caches it can.
     *  If false, caches are to be ignored.
     *  The default value comes from DefaultUseCaches, which defaults to
     * true.
     *
     * @see     java.net.URLConnection#useCaches
     */
    public void setUseCaches(boolean usecaches) {
        jarFileURLConnection.setUseCaches(usecaches);
    }

    
Returns the value of this URLConnection's
useCaches field.

See Also:
  • URLConnection.useCaches
Returns: the value of this URLConnection's
         useCaches field.
/**
     * Returns the value of this <code>URLConnection</code>'s
     * <code>useCaches</code> field.
     *
     * @return  the value of this <code>URLConnection</code>'s
     *          <code>useCaches</code> field.
     * @see     java.net.URLConnection#useCaches
     */
    public boolean getUseCaches() {
        return jarFileURLConnection.getUseCaches();
    }

    
Sets the value of the ifModifiedSince field of
this URLConnection to the specified value.

Params:
  • ifmodifiedsince –   the new value.
See Also:
  • URLConnection.ifModifiedSince
/**
     * Sets the value of the <code>ifModifiedSince</code> field of
     * this <code>URLConnection</code> to the specified value.
     *
     * @param   ifmodifiedsince   the new value.
     * @see     java.net.URLConnection#ifModifiedSince
     */
    public void setIfModifiedSince(long ifmodifiedsince) {
        jarFileURLConnection.setIfModifiedSince(ifmodifiedsince);
    }

    
Sets the default value of the useCaches field to the
specified value.

Params:
  • defaultusecaches –   the new value.
See Also:
  • URLConnection.useCaches
/**
     * Sets the default value of the <code>useCaches</code> field to the
     * specified value.
     *
     * @param   defaultusecaches   the new value.
     * @see     java.net.URLConnection#useCaches
     */
    public void setDefaultUseCaches(boolean defaultusecaches) {
        jarFileURLConnection.setDefaultUseCaches(defaultusecaches);
    }

    
Returns the default value of a URLConnection's
useCaches flag.


Ths default is "sticky", being a part of the static state of all
URLConnections.  This flag applies to the next, and all following
URLConnections that are created.

See Also:
  • URLConnection.useCaches
Returns: the default value of a URLConnection's
         useCaches flag.
/**
     * Returns the default value of a <code>URLConnection</code>'s
     * <code>useCaches</code> flag.
     * <p>
     * Ths default is "sticky", being a part of the static state of all
     * URLConnections.  This flag applies to the next, and all following
     * URLConnections that are created.
     *
     * @return  the default value of a <code>URLConnection</code>'s
     *          <code>useCaches</code> flag.
     * @see     java.net.URLConnection#useCaches
     */
    public boolean getDefaultUseCaches() {
        return jarFileURLConnection.getDefaultUseCaches();
    }
}