// Copyright 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.tapestry.portlet;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.portlet.ActionResponse;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.describe.RenderStrategy;
import org.apache.tapestry.error.ErrorMessages;
import org.apache.tapestry.error.ExceptionPresenter;
import org.apache.tapestry.error.RequestExceptionReporter;
import org.apache.tapestry.markup.MarkupWriterSource;
import org.apache.tapestry.services.ServiceConstants;
import org.apache.tapestry.util.ContentType;
import org.apache.tapestry.util.exception.ExceptionAnalyzer;
import org.apache.tapestry.util.exception.ExceptionDescription;
import org.apache.tapestry.util.exception.ExceptionProperty;
import org.apache.tapestry.web.WebRequest;
import org.apache.tapestry.web.WebResponse;
/**
* Service used to present a runtime exception to the user. This is very tricky in the Portlet world
* because of the split between the action and render requests (much more likely to get an error
* during the action request than during the render request, but both are possible).
* <p>
* During an action request, this code will render the HTML markup for the exception into a buffer
* that is stored as persistent attribute in the portal session.
*
* @author Howard M. Lewis Ship
* @since 4.0
*/
public class PortletExceptionPresenter implements ExceptionPresenter
{
private PortletRequestGlobals _globals;
private RenderStrategy _renderStrategy;
private WebRequest _request;
private RequestExceptionReporter _requestExceptionReporter;
private WebResponse _response;
private MarkupWriterSource _markupWriterSource;
public void presentException(IRequestCycle cycle, Throwable cause)
{
try
{
if (_globals.isRenderRequest())
reportRenderRequestException(cycle, cause);
else
reportActionRequestException(cycle, cause);
}
catch (Exception ex)
{
// Worst case scenario. The exception page itself is broken, leaving
// us with no option but to write the cause to the output.
// Also, write the exception thrown when redendering the exception
// page, so that can get fixed as well.
_requestExceptionReporter.reportRequestException(PortletMessages
.errorReportingException(ex), ex);
// And throw the exception.
throw new ApplicationRuntimeException(ex.getMessage(), ex);
}
_requestExceptionReporter.reportRequestException(ErrorMessages
.unableToProcessClientRequest(cause), cause);
}
private void reportActionRequestException(IRequestCycle cycle, Throwable cause)
{
CharArrayWriter caw = new CharArrayWriter();
PrintWriter pw = new PrintWriter(caw);
IMarkupWriter writer = _markupWriterSource
.newMarkupWriter(pw, new ContentType("text/html"));
writeException(writer, cycle, cause);
writer.close();
String markup = caw.toString();
_request.getSession(true).setAttribute(
PortletConstants.PORTLET_EXCEPTION_MARKUP_ATTRIBUTE,
markup);
ActionResponse response = _globals.getActionResponse();
response.setRenderParameter(ServiceConstants.SERVICE, PortletConstants.EXCEPTION_SERVICE);
}
private void reportRenderRequestException(IRequestCycle cycle, Throwable cause)
throws IOException
{
PrintWriter pw = _response.getPrintWriter(new ContentType("text/html"));
IMarkupWriter writer = _markupWriterSource
.newMarkupWriter(pw, new ContentType("text/html"));
writeException(writer, cycle, cause);
}
public void setGlobals(PortletRequestGlobals globals)
{
_globals = globals;
}
public void setRenderStrategy(RenderStrategy renderStrategy)
{
_renderStrategy = renderStrategy;
}
public void setRequest(WebRequest request)
{
_request = request;
}
public void setRequestExceptionReporter(RequestExceptionReporter requestExceptionReporter)
{
_requestExceptionReporter = requestExceptionReporter;
}
public void setResponse(WebResponse response)
{
_response = response;
}
public void setMarkupWriterSource(MarkupWriterSource markupWriterSource)
{
_markupWriterSource = markupWriterSource;
}
private void writeException(IMarkupWriter writer, IRequestCycle cycle,
ExceptionDescription exception, boolean showStackTrace)
{
writer.begin("div");
writer.attribute("class", "portlet-section-header");
writer.print(exception.getExceptionClassName());
writer.end();
writer.println();
writer.begin("div");
writer.attribute("class", "portlet-msg-error");
writer.print(exception.getMessage());
writer.end();
writer.println();
ExceptionProperty[] properties = exception.getProperties();
if (properties.length > 0)
{
writer.begin("table");
writer.attribute("class", "portlet-section-subheader");
for (int i = 0; i < properties.length; i++)
{
writer.begin("tr");
writer.attribute("class", i % 2 == 0 ? "portlet-section-body"
: "portlet-section-alternate");
writer.begin("th");
writer.print(properties[i].getName());
writer.end();
writer.println();
writer.begin("td");
_renderStrategy.renderObject(properties[i].getValue(), writer, cycle);
writer.end("tr");
writer.println();
}
writer.end();
writer.println();
}
if (!showStackTrace)
return;
writer.begin("ul");
String[] trace = exception.getStackTrace();
for (int i = 0; i < trace.length; i++)
{
writer.begin("li");
writer.print(trace[i]);
writer.end();
writer.println();
}
writer.end();
writer.println();
}
private void writeException(IMarkupWriter writer, IRequestCycle cycle, Throwable cause)
{
ExceptionDescription[] exceptions = new ExceptionAnalyzer().analyze(cause);
for (int i = 0; i < exceptions.length; i++)
writeException(writer, cycle, exceptions[i], i + 1 == exceptions.length);
}
}