Java tutorial
/************************************************************************* * Copyright 2009-2013 Eucalyptus Systems, Inc. * * This program 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; version 3 of the License. * * This program 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 this program. If not, see http://www.gnu.org/licenses/. * * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need * additional information or have any questions. ************************************************************************/ package com.eucalyptus.ws.util; import org.apache.log4j.Logger; import org.jboss.netty.handler.codec.http.HttpResponseStatus; import org.mule.api.MessagingException; import org.mule.message.ExceptionMessage; import com.eucalyptus.binding.BindingManager; import com.eucalyptus.context.Contexts; import com.eucalyptus.records.EventRecord; import com.eucalyptus.records.EventType; import com.eucalyptus.records.Logs; import com.eucalyptus.system.Ats; import com.eucalyptus.util.CollectionUtils; import com.eucalyptus.util.EucalyptusCloudException; import com.eucalyptus.util.Exceptions; import com.eucalyptus.util.LogUtil; import com.eucalyptus.ws.EucalyptusWebServiceException; import com.eucalyptus.ws.HasHttpStatusCode; import com.eucalyptus.ws.Role; import com.eucalyptus.ws.protocol.QueryBindingInfo; import com.google.common.base.Functions; import com.google.common.base.Optional; import com.google.common.base.Predicates; import com.google.common.collect.Iterables; import edu.ucsb.eucalyptus.msgs.BaseMessage; import edu.ucsb.eucalyptus.msgs.BaseMessageSupplier; import edu.ucsb.eucalyptus.msgs.ErrorDetail; import edu.ucsb.eucalyptus.msgs.ErrorResponse; import edu.ucsb.eucalyptus.msgs.EucalyptusErrorMessageType; /** * Support for service error handler implementations */ public abstract class ErrorHandlerSupport { private final Logger LOG; private final String namespace; private final String defaultCode; protected ErrorHandlerSupport(final Logger logger, final String namespace, final String defaultCode) { this.LOG = logger; this.namespace = namespace; this.defaultCode = defaultCode; } @SuppressWarnings("ThrowableResultOfMethodCallIgnored") public void handle(final ExceptionMessage exMsg) { EventRecord.here(getClass(), EventType.MSG_REPLY, exMsg.getPayload().getClass().getSimpleName()).debug(); final Throwable exception = exMsg.getException(); if (exception instanceof MessagingException && exception.getCause() instanceof EucalyptusCloudException) { try { final EucalyptusCloudException cloudException = (EucalyptusCloudException) exception.getCause(); final BaseMessage payload = parsePayload(exMsg.getPayload()); final HttpResponseStatus status; final Role role; final String code; if (cloudException instanceof EucalyptusWebServiceException) { final EucalyptusWebServiceException webServiceException = (EucalyptusWebServiceException) cloudException; role = webServiceException.getRole(); code = webServiceException.getCode(); } else { role = Role.Receiver; code = defaultCode; } final Optional<Integer> statusCodeOptional = getHttpResponseStatus(cloudException); status = !statusCodeOptional.isPresent() ? HttpResponseStatus.INTERNAL_SERVER_ERROR : new HttpResponseStatus(statusCodeOptional.get(), code); final BaseMessage errorResp = buildErrorResponse(payload.getCorrelationId(), role, code, cloudException.getMessage()); Contexts.response(new BaseMessageSupplier(errorResp, status)); } catch (final PayloadParseException e) { LOG.error("Failed to parse payload ", e.getCause()); } } else { final BaseMessage errorResp = buildFatalResponse(exception); Contexts.response(new BaseMessageSupplier(errorResp, HttpResponseStatus.INTERNAL_SERVER_ERROR)); } } private BaseMessage buildFatalResponse(Throwable exception) { final ErrorResponse errorResponse = new ErrorResponse(); ErrorDetail error = new ErrorDetail(); error.setCode(HttpResponseStatus.INTERNAL_SERVER_ERROR.getCode()); error.setMessage(exception.getMessage()); error.setType(defaultCode); if (Logs.isDebug()) { error.setStackTrace(Exceptions.string(exception)); } return errorResponse; } /** * Implementations construct a service specific message from the parameters. * * @param correlationId The request message identifier * @param role The role for the error * @param code The code for the error * @param message The message for the error * @return The error message */ protected abstract BaseMessage buildErrorResponse(String correlationId, Role role, String code, String message); protected static Optional<Integer> getHttpResponseStatus(final Throwable t) { final QueryBindingInfo info = Ats.inClassHierarchy(t.getClass()).get(QueryBindingInfo.class); final Optional<Integer> status = info == null ? Optional.<Integer>absent() : Optional.of(info.statusCode()); return Iterables.tryFind(Exceptions.causes(t), Predicates.instanceOf(HasHttpStatusCode.class)) .transform(Functions.compose(HasHttpStatusCode.Utils.httpStatusCode(), CollectionUtils.cast(HasHttpStatusCode.class))) .or(status); } private BaseMessage parsePayload(final Object payload) throws PayloadParseException { if (payload instanceof BaseMessage) { return (BaseMessage) payload; } else if (payload instanceof String) { try { return (BaseMessage) BindingManager.getBinding(namespace).fromOM((String) payload); } catch (Exception e) { throw new PayloadParseException(e); } } return new EucalyptusErrorMessageType(getClass().getSimpleName(), LogUtil.dumpObject(payload)); } private static final class PayloadParseException extends Exception { private static final long serialVersionUID = 1L; public PayloadParseException(final Throwable cause) { super(cause); } } }