urlconnection.java

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	return getHeaderField("content-type");
    }

    /**
     * Returns the value of the <code>content-encoding</code> header field.
     *
     * @return  the content encoding of the resource that the URL references,
     *          or <code>null</code> if not known.
     * @see     java.net.URLConnection#getHeaderField(java.lang.String)
     */
    public String getContentEncoding() {
	return getHeaderField("content-encoding");
    }

    /**
     * Returns the value of the <code>expires</code> header field. 
     *
     * @return  the expiration date of the resource that this URL references,
     *          or 0 if not known. The value is the number of milliseconds since
     *          January 1, 1970 GMT.
     * @see     java.net.URLConnection#getHeaderField(java.lang.String)
     */
    public long getExpiration() {
	return getHeaderFieldDate("expires", 0);
    }

    /**
     * Returns the value of the <code>date</code> header field. 
     *
     * @return  the sending date of the resource that the URL references,
     *          or <code>0</code> if not known. The value returned is the
     *          number of milliseconds since January 1, 1970 GMT.
     * @see     java.net.URLConnection#getHeaderField(java.lang.String)
     */
    public long getDate() {
	return getHeaderFieldDate("date", 0);
    }

    /**
     * Returns the value of the <code>last-modified</code> header field. 
     * The result is the number of milliseconds since January 1, 1970 GMT.
     *
     * @return  the date the resource referenced by this
     *          <code>URLConnection</code> was last modified, or 0 if not known.
     * @see     java.net.URLConnection#getHeaderField(java.lang.String)
     */
    public long getLastModified() {
	return getHeaderFieldDate("last-modified", 0);
    }

    /**
     * Returns the value of the named header field.
     * <p>
     * If called on a connection that sets the same header multiple times
     * with possibly different values, only the last value is returned.
     * 
     *
     * @param   name   the name of a header field.
     * @return  the value of the named header field, or <code>null</code>
     *          if there is no such field in the header.
     */
    public String getHeaderField(String name) {
	return null;
    }

    /**
     * Returns an unmodifiable Map of the header fields.
     * The Map keys are Strings that represent the
     * response-header field names. Each Map value is an
     * unmodifiable List of Strings that represents 
     * the corresponding field values.
     *
     * @return a Map of header fields
     * @since 1.4
     */
    public Map getHeaderFields() {
        return Collections.EMPTY_MAP;
    }

    /**
     * Returns the value of the named field parsed as a number.
     * <p>
     * This form of <code>getHeaderField</code> exists because some 
     * connection types (e.g., <code>http-ng</code>) have pre-parsed 
     * headers. Classes for that connection type can override this method 
     * and short-circuit the parsing. 
     *
     * @param   name      the name of the header field.
     * @param   Default   the default value.
     * @return  the value of the named field, parsed as an integer. The
     *          <code>Default</code> value is returned if the field is
     *          missing or malformed.
     */
    public int getHeaderFieldInt(String name, int Default) {
	String value = getHeaderField(name);
	try {
	    return Integer.parseInt(value);
	} catch (Exception e) { }
	return Default;
    }

    /**
     * Returns the value of the named field parsed as date.
     * The result is the number of milliseconds since January 1, 1970 GMT
     * represented by the named field. 
     * <p>
     * This form of <code>getHeaderField</code> exists because some 
     * connection types (e.g., <code>http-ng</code>) have pre-parsed 
     * headers. Classes for that connection type can override this method 
     * and short-circuit the parsing. 
     *
     * @param   name     the name of the header field.
     * @param   Default   a default value.
     * @return  the value of the field, parsed as a date. The value of the
     *          <code>Default</code> argument is returned if the field is
     *          missing or malformed.
     */
    public long getHeaderFieldDate(String name, long Default) {
	try {
            DateFormat df = DateFormat.getDateInstance();
	    
	    return df.parse(getHeaderField(name)).getTime();
	} catch(Throwable t) {}
	return Default;
    }

    /**
     * Returns the key for the <code>n</code><sup>th</sup> header field.
     * It returns <code>null</code> if there are fewer than <code>n+1</code> fields. 
     *
     * @param   n   an index, where n>=0
     * @return  the key for the <code>n</code><sup>th</sup> header field,
     *          or <code>null</code> if there are fewer than <code>n+1</code>
     *		fields.
     */
    public String getHeaderFieldKey(int n) {
	return null;
    }

    /**
     * Returns the value for the <code>n</code><sup>th</sup> header field. 
     * It returns <code>null</code> if there are fewer than
     * <code>n+1</code>fields. 
     * <p>
     * This method can be used in conjunction with the 
     * {@link #getHeaderFieldKey(int) getHeaderFieldKey} method to iterate through all 
     * the headers in the message. 
     *
     * @param   n   an index, where n>=0
     * @return  the value of the <code>n</code><sup>th</sup> header field
     *		or <code>null</code> if there are fewer than <code>n+1</code> fields
     * @see     java.net.URLConnection#getHeaderFieldKey(int)
     */
    public String getHeaderField(int n) {
	return null;
    }

    /**
     * Retrieves the contents of this URL connection. 
     * <p>
     * This method first determines the content type of the object by 
     * calling the <code>getContentType</code> method. If this is 
     * the first time that the application has seen that specific content 
     * type, a content handler for that content type is created: 
     * <ol>
     * <li>If the application has set up a content handler factory instance
     *     using the <code>setContentHandlerFactory</code> method, the
     *     <code>createContentHandler</code> method of that instance is called
     *     with the content type as an argument; the result is a content
     *     handler for that content type.
     * <li>If no content handler factory has yet been set up, or if the
     *     factory's <code>createContentHandler</code> method returns
     *     <code>null</code>, then the application loads the class named:
     *     <blockquote><pre>
     *         sun.net.www.content.&lt;<i>contentType</i>&gt;
     *     </pre></blockquote>
     *     where &lt;<i>contentType</i>&gt; is formed by taking the
     *     content-type string, replacing all slash characters with a
     *     <code>period</code> ('.'), and all other non-alphanumeric characters
     *     with the underscore character '<code>_</code>'. The alphanumeric
     *     characters are specifically the 26 uppercase ASCII letters
     *     '<code>A</code>' through '<code>Z</code>', the 26 lowercase ASCII
     *     letters '<code>a</code>' through '<code>z</code>', and the 10 ASCII
     *     digits '<code>0</code>' through '<code>9</code>'. If the specified
     *     class does not exist, or is not a subclass of
     *     <code>ContentHandler</code>, then an
     *     <code>UnknownServiceException</code> is thrown.
     * </ol>
     *
     * @return     the object fetched. The <code>instanceof</code> operator
     *               should be used to determine the specific kind of object
     *               returned.
     * @exception  IOException              if an I/O error occurs while
     *               getting the content.
     * @exception  UnknownServiceException  if the protocol does not support
     *               the content type.
     * @see        java.net.ContentHandlerFactory#createContentHandler(java.lang.String)
     * @see        java.net.URLConnection#getContentType()
     * @see        java.net.URLConnection#setContentHandlerFactory(java.net.ContentHandlerFactory)
     */
    public Object getContent() throws IOException {
        // Must call getInputStream before GetHeaderField gets called
        // so that FileNotFoundException has a chance to be thrown up
        // from here without being caught.
        getInputStream();
	return getContentHandler().getContent(this);
    }

    /**
     * Retrieves the contents of this URL connection. 
     *
     * @param classes the <code>Class</code> array 
     * indicating the requested types
     * @return     the object fetched that is the first match of the type
     *               specified in the classes array. null if none of 
     *               the requested types are supported.
     *               The <code>instanceof</code> operator should be used to 
     *               determine the specific kind of object returned.
     * @exception  IOException              if an I/O error occurs while
     *               getting the content.
     * @exception  UnknownServiceException  if the protocol does not support
     *               the content type.
     * @see        java.net.URLConnection#getContent()
     * @see        java.net.ContentHandlerFactory#createContentHandler(java.lang.String)
     * @see        java.net.URLConnection#getContent(java.lang.Class[])
     * @see        java.net.URLConnection#setContentHandlerFactory(java.net.ContentHandlerFactory)
     */
    public Object getContent(Class[] classes) throws IOException {
        // Must call getInputStream before GetHeaderField gets called
        // so that FileNotFoundException has a chance to be thrown up
        // from here without being caught.
        getInputStream();
	return getContentHandler().getContent(this, classes);
    }

    /**  
     * Returns a permission object representing the permission
     * necessary to make the connection represented by this
     * object. This method returns null if no permission is
     * required to make the connection. By default, this method
     * returns <code>java.security.AllPermission</code>. Subclasses
     * should override this method and return the permission
     * that best represents the permission required to make a 
     * a connection to the URL. For example, a <code>URLConnection</code>
     * representing a <code>file:</code> URL would return a 
     * <code>java.io.FilePermission</code> object.
     *
     * <p>The permission returned may dependent upon the state of the
     * connection. For example, the permission before connecting may be
     * different from that after connecting. For example, an HTTP
     * sever, say foo.com, may redirect the connection to a different
     * host, say bar.com. Before connecting the permission returned by
     * the connection will represent the permission needed to connect
     * to foo.com, while the permission returned after connecting will
     * be to bar.com.
     * 
     * <p>Permissions are generally used for two purposes: to protect
     * caches of objects obtained through URLConnections, and to check
     * the right of a recipient to learn about a particular URL. In
     * the first case, the permission should be obtained
     * <em>after</em> the object has been obtained. For example, in an
     * HTTP connection, this will represent the permission to connect
     * to the host from which the data was ultimately fetched. In the
     * second case, the permission should be obtained and tested
     * <em>before</em> connecting.
     *
     * @return the permission object representing the permission
     * necessary to make the connection represented by this
     * URLConnection. 
     *
     * @exception IOException if the computation of the permission
     * requires network or file I/O and an exception occurs while
     * computing it.  
     */
    public Permission getPermission() throws IOException {
	return SecurityConstants.ALL_PERMISSION;
    }

    /**
     * Returns an input stream that reads from this open connection.
     *
     * @return     an input stream that reads from this open connection.
     * @exception  IOException              if an I/O error occurs while
     *               creating the input stream.
     * @exception  UnknownServiceException  if the protocol does not support
     *               input.
     */
    public InputStream getInputStream() throws IOException {
	throw new UnknownServiceException("protocol doesn't support input");
    }

    /**
     * Returns an output stream that writes to this connection.
     *
     * @return     an output stream that writes to this connection.
     * @exception  IOException              if an I/O error occurs while
     *               creating the output stream.
     * @exception  UnknownServiceException  if the protocol does not support
     *               output.
     */
    public OutputStream getOutputStream() throws IOException {
	throw new UnknownServiceException("protocol doesn't support output");
    }

    /**
     * Returns a <code>String</code> representation of this URL connection.
     *
     * @return  a string representation of this <code>URLConnection</code>.
     */
    public String toString() {
	return this.getClass().getName() + ":" + url;
    }

    /**
     * Sets the value of the <code>doInput</code> field for this 
     * <code>URLConnection</code> to the specified value. 
     * <p>
     * A URL connection can be used for input and/or output.  Set the DoInput
     * flag to true if you intend to use the URL connection for input,
     * false if not.  The default is true.
     *
     * @param   doinput   the new value.
     * @throws IllegalStateException if already connected
     * @see     java.net.URLConnection#doInput
     * @see #getDoInput()
     */
    public void setDoInput(boolean doinput) {
	if (connected)
	    throw new IllegalStateException("Already connected");
	doInput = doinput;
    }

    /**
     * Returns the value of this <code>URLConnection</code>'s
     * <code>doInput</code> flag.
     *
     * @return  the value of this <code>URLConnection</code>'s
     *          <code>doInput</code> flag.
     * @see     #setDoInput(boolean)
     */
    public boolean getDoInput() {
	return doInput;
    }

    /**
     * Sets the value of the <code>doOutput</code> field for this 
     * <code>URLConnection</code> to the specified value. 
     * <p>
     * A URL connection can be used for input and/or output.  Set the DoOutput
     * flag to true if you intend to use the URL connection for output,
     * false if not.  The default is false.
     *
     * @param   dooutput   the new value.
     * @throws IllegalStateException if already connected
     * @see #getDoOutput()
     */
    public void setDoOutput(boolean dooutput) {
	if (connected)
	    throw new IllegalStateException("Already connected");
	doOutput = dooutput;
    }

    /**
     * Returns the value of this <code>URLConnection</code>'s
     * <code>doOutput</code> flag.
     *
     * @return  the value of this <code>URLConnection</code>'s
     *          <code>doOutput</code> flag.
     * @see     #setDoOutput(boolean)
     */
    public boolean getDoOutput() {
	return doOutput;
    }

    /**
     * Set the value of the <code>allowUserInteraction</code> field of 
     * this <code>URLConnection</code>. 
     *
     * @param   allowuserinteraction   the new value.
     * @throws IllegalStateException if already connected
     * @see     #getAllowUserInteraction()
     */
    public void setAllowUserInteraction(boolean allowuserinteraction) {
	if (connected)
	    throw new IllegalStateException("Already connected");
	allowUserInteraction = allowuserinteraction;
    }

    /**
     * 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     #setAllowUserInteraction(boolean)
     */
    public boolean getAllowUserInteraction() {
	return allowUserInteraction;
    }

    /**