webclient.java

这是远程web服务调用的一个包,可以将JSP直接作为服务

    public void addWindowListener( WebWindowListener listener ) {
        synchronized (_windowListeners) {
            if (listener != null && !_windowListeners.contains( listener )) _windowListeners.add( listener );
        }
    }


    /**
     * Removes a listener to watch for window openings and closings.
     */
    public void removeWindowListener( WebWindowListener listener ) {
        synchronized (_windowListeners) {
            _windowListeners.remove( listener );
        }
    }


    /**
     * Returns the next javascript alert without removing it from the queue.
     */
    public String getNextAlert() {
        return _alerts.isEmpty() ? null : (String) _alerts.getFirst();
    }


    /**
     * Returns the next javascript alert and removes it from the queue. If the queue is empty,
     * will return an empty string.
     */
    public String popNextAlert() {
        if (_alerts.isEmpty()) return "";
        return (String) _alerts.removeFirst();
    }


    /**
     * Specifies the object which will respond to all dialogs.
     **/
    public void setDialogResponder( DialogResponder responder ) {
        _dialogResponder = responder;
    }


//------------------------------------------ protected members -----------------------------------


    protected WebClient() {
        _openWindows.add( _mainWindow );
    }


    /**
     * Creates a web response object which represents the response to the specified web request.
     * @param request the request to which the response should be generated
     * @param targetFrame the frame in which the response should be stored
     **/
    abstract
    protected WebResponse newResponse( WebRequest request, FrameSelector targetFrame ) throws MalformedURLException, IOException;


    /**
     * Writes the message body for the request.
     **/
    final protected void writeMessageBody( WebRequest request, OutputStream stream ) throws IOException {
        request.writeMessageBody( stream );
    }


    /**
     * Returns the value of all current header fields.
     **/
    protected Dictionary getHeaderFields( URL targetURL ) {
        Hashtable result = (Hashtable) _headers.clone();
        result.put( "User-Agent", getClientProperties().getUserAgent() );
        if (getClientProperties().isAcceptGzip()) result.put( "Accept-Encoding", "gzip" );
        AddHeaderIfNotNull( result, "Cookie", _cookieJar.getCookieHeaderField( targetURL ) );
        AddHeaderIfNotNull( result, "Authorization", _authorizationString );
        AddHeaderIfNotNull( result, "Proxy-Authorization", _proxyAuthorizationString );
        return result;
    }


    private void AddHeaderIfNotNull( Hashtable result, final String headerName, final String headerValue ) {
        if (headerValue != null) result.put( headerName, headerValue );
    }


    /**
     * Updates this web client based on a received response. This includes updating
     * cookies and frames.  This method is required by ServletUnit, which cannot call the updateWindow method directly.
     **/
    final
    protected void updateMainWindow( FrameSelector frame, WebResponse response ) throws MalformedURLException, IOException, SAXException {
        getMainWindow().updateWindow( frame.getName(), response, new RequestContext() );
    }


//------------------------------------------------- package members ----------------------------------------------------


    void tellListeners( WebRequest request ) {
        List listeners;

        synchronized (_clientListeners) {
            listeners = new ArrayList( _clientListeners );
        }

        for (Iterator i = listeners.iterator(); i.hasNext();) {
            ((WebClientListener) i.next()).requestSent( this, request );
        }
    }


    void tellListeners( WebResponse response ) {
        List listeners;

        synchronized (_clientListeners) {
            listeners = new ArrayList( _clientListeners );
        }

        for (Iterator i = listeners.iterator(); i.hasNext();) {
            ((WebClientListener) i.next()).responseReceived( this, response );
        }
    }


    void updateClient( WebResponse response ) throws IOException {
        if (getClientProperties().isAcceptCookies()) _cookieJar.updateCookies( response.getCookieJar() );
        validateHeaders( response );
    }


    CookieJar getCookieJar() {
        return _cookieJar;
    }


    void updateFrameContents( WebWindow requestWindow, String requestTarget, WebResponse response, RequestContext requestContext ) throws IOException, SAXException {
        if (response.getFrame() == FrameSelector.NEW_FRAME) {
            WebWindow window = new WebWindow( this, requestWindow.getCurrentPage() );
            if (!WebRequest.NEW_WINDOW.equalsIgnoreCase( requestTarget )) window.setName( requestTarget );
            response.setFrame( window.getTopFrame() );
            window.updateFrameContents( response, requestContext );
            _openWindows.add( window );
            reportWindowOpened( window );
        } else if (response.getFrame().getWindow() != null && response.getFrame().getWindow() != requestWindow) {
            response.getFrame().getWindow().updateFrameContents( response, requestContext );
        } else {
            if (response.getFrame() == FrameSelector.TOP_FRAME) response.setFrame( requestWindow.getTopFrame() );
            requestWindow.updateFrameContents( response, requestContext );
        }
    }


    void close( WebWindow window ) {
        if (!_openWindows.contains( window )) throw new IllegalStateException( "Window is already closed" );
        _openWindows.remove( window );
        if (_openWindows.isEmpty()) _openWindows.add( new WebWindow( this ) );
        if (window.equals( _mainWindow )) _mainWindow = (WebWindow) _openWindows.get(0);
        reportWindowClosed( window );
    }


    private void reportWindowOpened( WebWindow window ) {
        List listeners;

        synchronized (_windowListeners) {
            listeners = new ArrayList( _windowListeners );
        }

        for (Iterator i = listeners.iterator(); i.hasNext();) {
            ((WebWindowListener) i.next()).windowOpened( this, window );
        }
    }


    private void reportWindowClosed( WebWindow window ) {
        List listeners;

        synchronized (_windowListeners) {
            listeners = new ArrayList( _windowListeners );
        }

        for (Iterator i = listeners.iterator(); i.hasNext();) {
            ((WebWindowListener) i.next()).windowClosed( this, window );
        }
    }

//------------------------------------------ package members ------------------------------------


    boolean getConfirmationResponse( String message ) {
        return _dialogResponder.getConfirmation( message );
    }


    String getUserResponse( String message, String defaultResponse ) {
        return _dialogResponder.getUserResponse( message, defaultResponse );
    }


    void postAlert( String message ) {
        _alerts.addLast( message );
    }

//------------------------------------------ private members -------------------------------------

    /** The list of alerts generated by JavaScript. **/
    private LinkedList _alerts = new LinkedList();

    /** The currently defined cookies. **/
    private CookieJar _cookieJar = new CookieJar();


    /** A map of header names to values. **/
    private HeaderDictionary _headers = new HeaderDictionary();

    private boolean _exceptionsThrownOnErrorStatus = HttpUnitOptions.getExceptionsThrownOnErrorStatus();

    private List _clientListeners = new ArrayList();

    private List _windowListeners = new ArrayList();

    private DialogResponder _dialogResponder = new DialogAdapter();

    private ClientProperties _clientProperties = ClientProperties.getDefaultProperties().cloneProperties();


    /**
     * Examines the headers in the response and throws an exception if appropriate.
     **/
    private void validateHeaders( WebResponse response ) throws HttpException {
        if (!getExceptionsThrownOnErrorStatus()) return;

        if (response.getHeaderField( "WWW-Authenticate" ) != null) {
            throw new AuthorizationRequiredException( response.getHeaderField( "WWW-Authenticate" ) );
        } else if (response.getResponseCode() == HttpURLConnection.HTTP_INTERNAL_ERROR) {
            throw new HttpInternalErrorException( response.getURL() );
        } else if (response.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
            throw new HttpNotFoundException( response.getResponseMessage(), response.getURL() );
        } else if (response.getResponseCode() >= HttpURLConnection.HTTP_BAD_REQUEST) {
            throw new HttpException( response.getResponseCode(), response.getResponseMessage(), response.getURL() );
        }
    }


    FrameSelector findFrame( String target ) {
        for (int i = 0; i < _openWindows.size(); i++) {
            WebWindow webWindow = (WebWindow) _openWindows.get( i );
            FrameSelector frame = webWindow.getFrame( target );
            if (frame != null) return frame;
        }
        return null;
    }


//==================================================================================================


    static public class HeaderDictionary extends Hashtable {

        public void addEntries( Dictionary source ) {
            for (Enumeration e = source.keys(); e.hasMoreElements(); ) {
                Object key = e.nextElement();
                put( key, source.get( key ) );
            }
        }


        public boolean containsKey( Object key ) {
            return super.containsKey( matchPreviousFieldName( key.toString() ) );
        }


        public Object get( Object fieldName ) {
            return (String) super.get( matchPreviousFieldName( fieldName.toString() ) );
        }


        public Object put( Object fieldName, Object fieldValue ) {
            fieldName = matchPreviousFieldName( fieldName.toString() );
            Object oldValue = super.get( fieldName );
            if (fieldValue == null) {
                remove( fieldName );
            } else {
                super.put( fieldName, fieldValue );
            }
            return oldValue;
        }


        /**
         * If a matching field name with different case is already known, returns the older name.
         * Otherwise, returns the specified name.
         **/
        private String matchPreviousFieldName( String fieldName ) {
            for (Enumeration e = keys(); e.hasMoreElements(); ) {
                String key = (String) e.nextElement();
                if (key.equalsIgnoreCase( fieldName )) return key;
            }
            return fieldName;
        }


    }

}


//==================================================================================================


class RedirectWebRequest extends WebRequest {


    RedirectWebRequest( WebResponse response ) throws MalformedURLException {
        super( response.getURL(), response.getHeaderField( "Location" ), response.getFrame(), response.getFrameName() );
        if (response.getReferer() != null) setHeaderField( "Referer", response.getReferer() );
    }


    /**
     * Returns the HTTP method defined for this request.
     **/
    public String getMethod() {
        return "GET";
    }
}