CustomFaultInterceptor.java

/*
    This file is part of Cyclos (www.cyclos.org).
    A project of the Social Trade Organisation (www.socialtrade.org).

    Cyclos is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    Cyclos 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 for more details.

    You should have received a copy of the GNU General Public License
    along with Cyclos; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 */
package nl.strohalm.cyclos.webservices.interceptor;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map.Entry;

import javax.servlet.http.HttpServletRequest;

import nl.strohalm.cyclos.utils.MessageResolver;
import nl.strohalm.cyclos.utils.validation.ValidationError;
import nl.strohalm.cyclos.utils.validation.ValidationException;
import nl.strohalm.cyclos.webservices.WebServiceContext;
import nl.strohalm.cyclos.webservices.utils.WebServiceHelper;

import org.apache.commons.lang.StringUtils;
import org.apache.cxf.binding.soap.SoapFault;
import org.apache.cxf.binding.soap.SoapMessage;
import org.apache.cxf.binding.soap.interceptor.AbstractSoapInterceptor;
import org.apache.cxf.interceptor.Fault;
import org.apache.cxf.phase.Phase;

/**
 * An interceptor used to map known exceptions to fault codes
 * 
 * @author luis
 */
public class CustomFaultInterceptor extends AbstractSoapInterceptor {

    private WebServiceHelper webServiceHelper;
    private MessageResolver  messageResolver;

    public CustomFaultInterceptor() {
        super(Phase.MARSHAL);
    }

    @Override
    public void handleMessage(final SoapMessage message) throws Fault {
        final Fault fault = (Fault) message.getContent(Exception.class);
        // Only change the fault code if it was not generated by Cyclos
        if (!WebServiceHelper.isFromCyclos(fault)) {
            final Throwable exception = fault.getCause() == null ? fault : fault.getCause();
            final SoapFault soapFault = WebServiceHelper.fault(exception);
            fault.setDetail(null);
            fault.setFaultCode(soapFault.getFaultCode());
            fault.setMessage(message(exception));
        }
        // there are cases where this interceptor is invoked but the context wasn't initialized
        // (e.g.: there is a unmarshalling error when CXF is trying to convert the request parameters)
        //
        if (WebServiceContext.isInitialized()) {
            final HttpServletRequest request = WebServiceContext.getRequest();
            request.setAttribute("soapFault", fault);
        }
        webServiceHelper.error(fault);
    }

    public void setMessageResolver(final MessageResolver messageResolver) {
        this.messageResolver = messageResolver;
    }

    public void setWebServiceHelper(final WebServiceHelper webServiceHelper) {
        this.webServiceHelper = webServiceHelper;
    }

    private String message(final Throwable exception) {
        if (exception == null) {
            return "null";
        } else if (exception instanceof ValidationException) {
            return message((ValidationException) exception);
        } else {
            return exception.getMessage();
        }
    }

    private String message(final ValidationException e) {
        String key = "error.validation";
        List<Object> args = Collections.emptyList();
        if (!e.getGeneralErrors().isEmpty()) {
            final ValidationError error = e.getGeneralErrors().iterator().next();
            key = error.getKey();
            args = error.getArguments();
        } else if (!e.getErrorsByProperty().isEmpty()) {
            final Entry<String, Collection<ValidationError>> entry = e.getErrorsByProperty().entrySet().iterator().next();
            final Collection<ValidationError> errors = entry.getValue();
            if (!errors.isEmpty()) {
                // We must show the validation error in a friendly way
                final String propertyName = entry.getKey();
                final ValidationError error = errors.iterator().next();
                key = error.getKey();
                args = new ArrayList<Object>();
                // First, check if there's a fixed display name for the property...
                String propertyLabel = e.getPropertyDisplayName(propertyName);
                if (StringUtils.isEmpty(propertyLabel)) {
                    // ... it doesn't. Check if there's a message key...
                    final String propertyKey = e.getPropertyKey(propertyName);
                    if (StringUtils.isNotEmpty(propertyKey)) {
                        // ... the key is set! Get the property label from the message bundle.
                        propertyLabel = messageResolver.message(e.getPropertyKey(propertyName));
                    } else {
                        // ... we're out of luck! There's no property key. Use the raw property name as label, which is ugly!
                        propertyLabel = propertyName;
                    }
                }
                // The first message argument is always the property label
                args.add(propertyLabel);
                if (error.getArguments() != null) {
                    // If there are more, add them as well.
                    args.addAll(error.getArguments());
                }
            }
        }
        // With the key and arguments, we can show a friendly message to the user
        return messageResolver.message(key, args.toArray());
    }
}