pagecontextimpl.java

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            if (o != null)
                return o;
        }

        return context.getAttribute(name);
    }


    public Enumeration getAttributeNamesInScope(final int scope) {
        if (SecurityUtil.isPackageProtectionEnabled()){
            return (Enumeration)
                    AccessController.doPrivileged(new PrivilegedAction(){
                public Object run(){
                    return doGetAttributeNamesInScope(scope);
                }
            });
        } else {
            return doGetAttributeNamesInScope(scope);
        }
    }

    private Enumeration doGetAttributeNamesInScope(int scope){
        switch (scope) {
        case PAGE_SCOPE:
            return attributes.keys();

        case REQUEST_SCOPE:
            return request.getAttributeNames();

        case SESSION_SCOPE:
            if (session == null) {
            throw new IllegalStateException(
                        Localizer.getMessage("jsp.error.page.noSession"));
            }
            return session.getAttributeNames();

        case APPLICATION_SCOPE:
            return context.getAttributeNames();

        default:
            throw new IllegalArgumentException("Invalid scope");
        }
    }

    public void removeAttribute(final String name) {

        if (name == null) {
            throw new NullPointerException(
                    Localizer.getMessage("jsp.error.attribute.null_name"));
        }

        if (SecurityUtil.isPackageProtectionEnabled()){
            AccessController.doPrivileged(new PrivilegedAction(){
                public Object run(){
                    doRemoveAttribute(name);
                    return null;
                }
            });
        } else {
            doRemoveAttribute(name);
        }
    }


    private void doRemoveAttribute(String name){
        try {
            removeAttribute(name, PAGE_SCOPE);
            removeAttribute(name, REQUEST_SCOPE);
            if( session != null ) {
                    removeAttribute(name, SESSION_SCOPE);
                }
                removeAttribute(name, APPLICATION_SCOPE);
            } catch (Exception ex) {
            // we remove as much as we can, and
            // simply ignore possible exceptions
        }
    }

    public JspWriter getOut() {
    return out;
    }

    public HttpSession getSession() { return session; }
    public Servlet getServlet() { return servlet; }
    public ServletConfig getServletConfig() { return config; }
    public ServletContext getServletContext() {
    return config.getServletContext();
    }
    public ServletRequest getRequest() { return request; }
    public ServletResponse getResponse() { return response; }


    /**
     * Returns the exception associated with this page
     * context, if any.
     * <p/>
     * Added wrapping for Throwables to avoid ClassCastException:
     * see Bugzilla 31171 for details.
     *
     * @return The Exception associated with this page context, if any.
     */
    public Exception getException() {
        Throwable t = JspRuntimeLibrary.getThrowable(request);

        // Only wrap if needed
        if((t != null) && (! (t instanceof Exception))) {
            t = new JspException(t);
        }

        return (Exception) t;
    }


    public Object getPage() { return servlet; }


    private final String getAbsolutePathRelativeToContext(String relativeUrlPath) {
        String path = relativeUrlPath;

        if (!path.startsWith("/")) {
        String uri = (String)
        request.getAttribute("javax.servlet.include.servlet_path");
        if (uri == null)
        uri = ((HttpServletRequest) request).getServletPath();
            String baseURI = uri.substring(0, uri.lastIndexOf('/'));
            path = baseURI+'/'+path;
        }

        return path;
    }

    public void include(String relativeUrlPath)
            throws ServletException, IOException {
        JspRuntimeLibrary.include(request, response, relativeUrlPath, out,
                  true);
    }

    public void include(final String relativeUrlPath, final boolean flush)
            throws ServletException, IOException {
        if (SecurityUtil.isPackageProtectionEnabled()){
            try{
                AccessController.doPrivileged(new PrivilegedExceptionAction(){
                    public Object run() throws Exception{
                        doInclude(relativeUrlPath, flush);
                        return null;
                    }
                });
            } catch (PrivilegedActionException e){
                Exception ex =  e.getException();
                if (ex instanceof IOException){
                    throw (IOException)ex;
                } else {
                    throw (ServletException)ex;
                }
            }
        } else {
            doInclude(relativeUrlPath, flush);
        }
    }

    private void doInclude(String relativeUrlPath, boolean flush)
            throws ServletException, IOException {
        JspRuntimeLibrary.include(request, response, relativeUrlPath, out,
                  flush);
    }

    public VariableResolver getVariableResolver() {
    return this;
    }

    public void forward(final String relativeUrlPath)
        throws ServletException, IOException {
        if (SecurityUtil.isPackageProtectionEnabled()){
            try{
                AccessController.doPrivileged(new PrivilegedExceptionAction(){
                    public Object run() throws Exception{
                        doForward(relativeUrlPath);
                        return null;
                    }
                });
            } catch (PrivilegedActionException e){
                Exception ex =  e.getException();
                if (ex instanceof IOException){
                    throw (IOException)ex;
                } else {
                    throw (ServletException)ex;
                }
            }
        } else {
            doForward(relativeUrlPath);
        }
    }

    private void doForward(String relativeUrlPath)
        throws ServletException, IOException{

        // JSP.4.5 If the buffer was flushed, throw IllegalStateException
        try {
            out.clear();
        } catch (IOException ex) {
            IllegalStateException ise =
                new IllegalStateException(Localizer.getMessage(
                            "jsp.error.attempt_to_clear_flushed_buffer"));
            ise.initCause(ex);
            throw ise;
        }

        // Make sure that the response object is not the wrapper for include
        while (response instanceof ServletResponseWrapperInclude) {
            response = ((ServletResponseWrapperInclude)response).getResponse();
        }

        final String path = getAbsolutePathRelativeToContext(relativeUrlPath);
        String includeUri
            = (String) request.getAttribute(Constants.INC_SERVLET_PATH);

        final ServletResponse fresponse = response;
        final ServletRequest frequest = request;

        if (includeUri != null)
            request.removeAttribute(Constants.INC_SERVLET_PATH);
        try {
            context.getRequestDispatcher(path).forward(request, response);
        } finally {
            if (includeUri != null)
                request.setAttribute(Constants.INC_SERVLET_PATH, includeUri);
            request.setAttribute(Constants.FORWARD_SEEN, "true");
        }
    }

    public BodyContent pushBody() {
    return (BodyContent) pushBody(null);
    }

    public JspWriter pushBody(Writer writer) {
        depth++;
        if (depth >= outs.length) {
            BodyContentImpl[] newOuts = new BodyContentImpl[depth + 1];
            for (int i=0; i<outs.length; i++) {
                newOuts[i] = outs[i];
            }
            newOuts[depth] = new BodyContentImpl(out);
            outs = newOuts;
        }

    outs[depth].setWriter(writer);
        out = outs[depth];

    // Update the value of the "out" attribute in the page scope
    // attribute namespace of this PageContext
    setAttribute(OUT, out);

        return outs[depth];
    }

    public JspWriter popBody() {
        depth--;
        if (depth >= 0) {
            out = outs[depth];
        } else {
            out = baseOut;
        }

    // Update the value of the "out" attribute in the page scope
    // attribute namespace of this PageContext
    setAttribute(OUT, out);

        return out;
    }

    /**
     * Provides programmatic access to the ExpressionEvaluator.
     * The JSP Container must return a valid instance of an
     * ExpressionEvaluator that can parse EL expressions.
     */
    public ExpressionEvaluator getExpressionEvaluator() {
        return elExprEval;
    }

    public void handlePageException(Exception ex)
        throws IOException, ServletException
    {
        // Should never be called since handleException() called with a
        // Throwable in the generated servlet.
        handlePageException((Throwable) ex);
    }

    public void handlePageException(final Throwable t)
        throws IOException, ServletException
    {
        if (t == null)
            throw new NullPointerException("null Throwable");

        if (SecurityUtil.isPackageProtectionEnabled()){
            try{
                AccessController.doPrivileged(new PrivilegedExceptionAction(){
                    public Object run() throws Exception{
                        doHandlePageException(t);
                        return null;
                    }
                });
            } catch (PrivilegedActionException e){
                Exception ex =  e.getException();
                if (ex instanceof IOException){
                    throw (IOException)ex;
                } else {
                    throw (ServletException)ex;
                }
            }
        } else {
            doHandlePageException(t);
        }

    }

    private void doHandlePageException(Throwable t)
        throws IOException, ServletException {

        if (errorPageURL != null && !errorPageURL.equals("")) {

            /*
             * Set request attributes.
             * Do not set the javax.servlet.error.exception attribute here
             * (instead, set in the generated servlet code for the error page)
             * in order to prevent the ErrorReportValve, which is invoked as
             * part of forwarding the request to the error page, from
             * throwing it if the response has not been committed (the response
             * will have been committed if the error page is a JSP page).
             */
            request.setAttribute("javax.servlet.jsp.jspException", t);
            request.setAttribute("javax.servlet.error.status_code",
                new Integer(HttpServletResponse.SC_INTERNAL_SERVER_ERROR));
            request.setAttribute("javax.servlet.error.request_uri",
            ((HttpServletRequest) request).getRequestURI());
            request.setAttribute("javax.servlet.error.servlet_name",
                     config.getServletName());
            try {
                forward(errorPageURL);
            } catch (IllegalStateException ise) {
                include(errorPageURL);
            }

            // The error page could be inside an include.

            Object newException = request.getAttribute("javax.servlet.error.exception");

            // t==null means the attribute was not set.
            if( (newException!= null) && (newException==t) ) {
                request.removeAttribute("javax.servlet.error.exception");
            }

            // now clear the error code - to prevent double handling.
            request.removeAttribute("javax.servlet.error.status_code");
            request.removeAttribute("javax.servlet.error.request_uri");
            request.removeAttribute("javax.servlet.error.status_code");
            request.removeAttribute("javax.servlet.jsp.jspException");

        } else {
            // Otherwise throw the exception wrapped inside a ServletException.
            // Set the exception as the root cause in the ServletException
            // to get a stack trace for the real problem
            if (t instanceof IOException) throw (IOException)t;
            if (t instanceof ServletException) throw (ServletException)t;
            if (t instanceof RuntimeException) throw (RuntimeException)t;

            Throwable rootCause = null;
            if (t instanceof JspException) {
                rootCause = ((JspException) t).getRootCause();
            } else if (t instanceof ELException) {
                rootCause = ((ELException) t).getRootCause();
            }

            if (rootCause != null) {
                // FG start patch
                if (rootCause instanceof RuntimeException)
                {
                    throw (RuntimeException) rootCause;
                }
                rootCause.printStackTrace();
                // FG end patch
                throw new ServletException(t.getClass().getName() + ": " +
                                           t.getMessage(), rootCause);
            }

            throw new ServletException(t);
        }
    }

    /**
     * VariableResolver interface
     */
    public Object resolveVariable(String pName) throws ELException {
    return variableResolver.resolveVariable(pName);
    }

    private static String XmlEscape(String s) {
        if (s == null) return null;
        StringBuffer sb = new StringBuffer();
        for(int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '<') {
                sb.append("&lt;");
            } else if (c == '>') {
                sb.append("&gt;");
            } else if (c == '\'') {
                sb.append("&#039;");    // &apos;
            } else if (c == '&') {
                sb.append("&amp;");
            } else if (c == '"') {
                sb.append("&#034;");    // &quot;
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }

    /**
     * Proprietary method to evaluate EL expressions.
     * XXX - This method should go away once the EL interpreter moves
     * out of JSTL and into its own project.  For now, this is necessary
     * because the standard machinery is too slow.
     *
     * @param expression The expression to be evaluated
     * @param expectedType The expected resulting type
     * @param pageContext The page context
     * @param functionMap Maps prefix and name to Method
     * @return The result of the evaluation
     */
    public static Object proprietaryEvaluate(final String expression,
                         final Class expectedType,
                         final PageContext pageContext,
                         final ProtectedFunctionMapper functionMap,
                         final boolean escape)
    throws ELException
    {
    Object retValue;
        if (SecurityUtil.isPackageProtectionEnabled()){
            try {
                retValue = AccessController.doPrivileged(
            new PrivilegedExceptionAction(){

                    public Object run() throws Exception{
                        return elExprEval.evaluate(expression,
                           expectedType,
                           pageContext.getVariableResolver(),
                           functionMap);
                    }
                });
            } catch (PrivilegedActionException ex) {
                Exception realEx = ex.getException();
        if (realEx instanceof ELException) {
            throw (ELException) realEx;
        } else {
            throw new ELException(realEx);
        }
            }
        } else {
        retValue = elExprEval.evaluate(expression,
                       expectedType,
                       pageContext.getVariableResolver(),
                       functionMap);
        }
    if (escape) {
        retValue = XmlEscape(retValue.toString());
    }

    return retValue;
    }

}