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Apache CXF example source code file (JAXRSOutInterceptor.java)

This example Apache CXF source code file (JAXRSOutInterceptor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Apache CXF tags/keywords

annotation, cachedoutputstream, cachingxmleventwriter, io, list, list, log, logging, map, map, multivaluedmap, object, object, operationresourceinfo, outputstream, reflection, response, response, text, util

The Apache CXF JAXRSOutInterceptor.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.cxf.jaxrs.interceptor;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.text.SimpleDateFormat;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.ResourceBundle;
import java.util.logging.Logger;

import javax.ws.rs.core.GenericEntity;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.XMLEvent;

import org.apache.cxf.common.i18n.BundleUtils;
import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.interceptor.AbstractOutDatabindingInterceptor;
import org.apache.cxf.io.CachedOutputStream;
import org.apache.cxf.jaxrs.ext.ResponseHandler;
import org.apache.cxf.jaxrs.impl.MetadataMap;
import org.apache.cxf.jaxrs.lifecycle.ResourceProvider;
import org.apache.cxf.jaxrs.model.ClassResourceInfo;
import org.apache.cxf.jaxrs.model.OperationResourceInfo;
import org.apache.cxf.jaxrs.model.ProviderInfo;
import org.apache.cxf.jaxrs.provider.ProviderFactory;
import org.apache.cxf.jaxrs.utils.HttpUtils;
import org.apache.cxf.jaxrs.utils.InjectionUtils;
import org.apache.cxf.jaxrs.utils.JAXRSUtils;
import org.apache.cxf.message.Exchange;
import org.apache.cxf.message.Message;
import org.apache.cxf.message.MessageContentsList;
import org.apache.cxf.phase.Phase;
import org.apache.cxf.staxutils.CachingXmlEventWriter;
import org.apache.cxf.staxutils.StaxUtils;
import org.apache.cxf.transport.http.AbstractHTTPDestination;

public class JAXRSOutInterceptor extends AbstractOutDatabindingInterceptor {
    private static final Logger LOG = LogUtils.getL7dLogger(JAXRSOutInterceptor.class);
    private static final ResourceBundle BUNDLE = BundleUtils.getBundle(JAXRSOutInterceptor.class);

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

    public void handleMessage(Message message) {
        
        try {
            processResponse(message);
        } finally {
            Object rootInstance = message.getExchange().remove(JAXRSUtils.ROOT_INSTANCE);
            Object rootProvider = message.getExchange().remove(JAXRSUtils.ROOT_PROVIDER);
            if (rootInstance != null && rootProvider != null) {
                try {
                    ((ResourceProvider)rootProvider).releaseInstance(message, rootInstance);
                } catch (Throwable tex) {
                    LOG.warning("Exception occurred during releasing the service instance, "
                                + tex.getMessage());
                }
            }
            ProviderFactory.getInstance(message).clearThreadLocalProxies();
            ClassResourceInfo cri =
                (ClassResourceInfo)message.getExchange().get(JAXRSUtils.ROOT_RESOURCE_CLASS);
            if (cri != null) {
                cri.clearThreadLocalProxies();
            }
        }
            

    }
    
    private void processResponse(Message message) {
        
        if (isResponseAlreadyHandled(message)) {
            return;
        }
        
        MessageContentsList objs = MessageContentsList.getContentsList(message);
        if (objs == null || objs.size() == 0) {
            return;
        }
        
        Object responseObj = objs.get(0);
        
        Response response = null;
        if (responseObj instanceof Response) {
            response = (Response)responseObj;
        } else {
            int status = getStatus(message, responseObj != null ? 200 : 204);
            response = Response.status(status).entity(responseObj).build();
        }
        
        Exchange exchange = message.getExchange();
        OperationResourceInfo ori = (OperationResourceInfo)exchange.get(OperationResourceInfo.class
            .getName());

        List<ProviderInfo handlers = 
            ProviderFactory.getInstance(message).getResponseHandlers();
        for (ProviderInfo<ResponseHandler> rh : handlers) {
            InjectionUtils.injectContextFields(rh.getProvider(), rh, 
                                               message.getExchange().getInMessage());
            InjectionUtils.injectContextFields(rh.getProvider(), rh, 
                                               message.getExchange().getInMessage());
            Response r = rh.getProvider().handleResponse(message, ori, response);
            if (r != null) {
                response = r;
            }
        }
        
        serializeMessage(message, response, ori, true);        
    }

    private int getStatus(Message message, int defaultValue) {
        Object customStatus = message.getExchange().get(Message.RESPONSE_CODE);
        return customStatus == null ? defaultValue : (Integer)customStatus;
    }
    
    @SuppressWarnings("unchecked")
    private void serializeMessage(Message message, 
                                  Response response, 
                                  OperationResourceInfo ori,
                                  boolean firstTry) {
        int status = response.getStatus();
        Object responseObj = response.getEntity();
        if (status == 200 && !isResponseNull(responseObj) && firstTry 
            && ori != null && JAXRSUtils.headMethodPossible(ori.getHttpMethod(), 
                (String)message.getExchange().getInMessage().get(Message.HTTP_REQUEST_METHOD))) {
            LOG.info(new org.apache.cxf.common.i18n.Message("HEAD_WITHOUT_ENTITY", BUNDLE).toString());
            responseObj = null;
        }
        if (status == -1) {
            status = isResponseNull(responseObj) ? 204 : 200;
        }
        
        message.put(Message.RESPONSE_CODE, status);
        Map<String, List theHeaders = 
            (Map<String, List)message.get(Message.PROTOCOL_HEADERS);
        if (firstTry && theHeaders != null) {
            // some headers might've been setup by custom cxf interceptors
            theHeaders.putAll((Map)response.getMetadata());
        } else {
            message.put(Message.PROTOCOL_HEADERS, response.getMetadata());
        }
        Map<String, List rh = 
            (Map<String, List)message.get(Message.PROTOCOL_HEADERS);
        MultivaluedMap<String, Object> responseHeaders;
        if (!(rh instanceof MultivaluedMap)) {
            responseHeaders = new MetadataMap<String, Object>(rh);
        } else {
            responseHeaders = (MultivaluedMap)rh;
        }
        setResponseDate((MultivaluedMap)responseHeaders, firstTry);
        if (isResponseNull(responseObj)) {
            return;
        }
        
        Object ignoreWritersProp = message.getExchange().get(JAXRSUtils.IGNORE_MESSAGE_WRITERS);
        boolean ignoreWriters = 
            ignoreWritersProp == null ? false : Boolean.valueOf(ignoreWritersProp.toString());
        if (ignoreWriters) {
            writeResponseToStream(message.getContent(OutputStream.class), responseObj);
            return;
        }
        
        List<MediaType> availableContentTypes = computeAvailableContentTypes(message, response);  
        
        Method invoked = null;
        if (firstTry) {
            invoked = ori == null ? null : ori.getAnnotatedMethod() == null
                ? ori.getMethodToInvoke() : ori.getAnnotatedMethod();
        }
        Class<?> targetType = getRawResponseClass(responseObj);
        Type genericType = 
            getGenericResponseType(ori == null ? null : ori.getAnnotatedMethod(), responseObj);
        if (genericType instanceof TypeVariable) {
            genericType = InjectionUtils.getSuperType(ori.getClassResourceInfo().getServiceClass(), 
                                                       (TypeVariable)genericType);
        }
        
        MessageBodyWriter writer = null;
        MediaType responseType = null;
        for (MediaType type : availableContentTypes) { 
            writer = ProviderFactory.getInstance(message)
                .createMessageBodyWriter(targetType, genericType, 
                      invoked != null ? invoked.getAnnotations() : new Annotation[]{}, 
                      type,
                      message);
            
            if (writer != null) {
                responseType = type;
                break;
            }
        }
    
        OutputStream outOriginal = message.getContent(OutputStream.class);
        if (writer == null) {
            message.put(Message.CONTENT_TYPE, "text/plain");
            message.put(Message.RESPONSE_CODE, 500);
            writeResponseErrorMessage(outOriginal, "NO_MSG_WRITER", targetType.getSimpleName());
            return;
        }
        boolean enabled = checkBufferingMode(message, writer, firstTry);
        Object entity = getEntity(responseObj);
        try {
            responseType = checkFinalContentType(responseType);
            LOG.fine("Response content type is: " + responseType.toString());
            message.put(Message.CONTENT_TYPE, responseType.toString());
            
            Annotation[] annotations = invoked != null ? invoked.getAnnotations() : new Annotation[]{};
            
            long size = writer.getSize(entity, targetType, genericType, annotations, responseType);
            if (size > 0) {
                LOG.fine("Setting ContentLength to " + size + " as requested by " 
                         + writer.getClass().getName());
                responseHeaders.putSingle(HttpHeaders.CONTENT_LENGTH, Long.toString(size));
            }
            
            LOG.fine("Response EntityProvider is: " + writer.getClass().getName());
            try {
                writer.writeTo(entity, targetType, genericType, 
                               annotations, 
                               responseType, 
                               responseHeaders, 
                               message.getContent(OutputStream.class));
                
                if (isResponseRedirected(message)) {
                    return;
                }
                
                Object newContentType = responseHeaders.getFirst(HttpHeaders.CONTENT_TYPE);
                if (newContentType != null) {
                    message.put(Message.CONTENT_TYPE, newContentType.toString());
                }
                checkCachedStream(message, outOriginal, enabled);
            } finally {
                if (enabled) {
                    message.setContent(OutputStream.class, outOriginal);
                    message.put(XMLStreamWriter.class.getName(), null);
                }
            }
            
        } catch (IOException ex) {
            handleWriteException(message, response, ori, ex, entity, firstTry);
        } catch (Throwable ex) {
            handleWriteException(message, response, ori, ex, entity, firstTry);
        }
    }
    
    private boolean isResponseNull(Object o) {
        return o == null || GenericEntity.class.isAssignableFrom(o.getClass()) 
                            && ((GenericEntity)o).getEntity() == null; 
    }
    
    private Object getEntity(Object o) {
        return GenericEntity.class.isAssignableFrom(o.getClass()) ? ((GenericEntity)o).getEntity() : o; 
    }
    
    private boolean checkBufferingMode(Message m, MessageBodyWriter w, boolean firstTry) {
        if (!firstTry) {
            return false;
        }
        Object outBuf = m.getContextualProperty(OUT_BUFFERING);
        boolean enabled = Boolean.TRUE.equals(outBuf) || "true".equals(outBuf);
        if (!enabled && outBuf == null) {
            enabled = InjectionUtils.invokeBooleanGetter(w, "getEnableBuffering");
        }
        if (enabled) {
            boolean streamingOn = InjectionUtils.invokeBooleanGetter(w, "getEnableStreaming");
            if (streamingOn) {
                m.setContent(XMLStreamWriter.class, new CachingXmlEventWriter());
            } else {
                m.setContent(OutputStream.class, new CachedOutputStream());
            }
        }
        return enabled;
    }
    
    private void checkCachedStream(Message m, OutputStream osOriginal, boolean enabled) throws Exception {
        XMLStreamWriter writer = null;
        if (enabled) {
            writer = m.getContent(XMLStreamWriter.class);
        } else {
            writer = (XMLStreamWriter)m.get(XMLStreamWriter.class.getName());
        }
        if (writer instanceof CachingXmlEventWriter) {
            CachingXmlEventWriter cache = (CachingXmlEventWriter)writer;
            if (cache.getEvents().size() != 0) {
                XMLStreamWriter origWriter = StaxUtils.createXMLStreamWriter(osOriginal);
                for (XMLEvent event : cache.getEvents()) {
                    StaxUtils.writeEvent(event, origWriter);
                }
            }
            m.setContent(XMLStreamWriter.class, null);
            return;
        }
        if (enabled) {
            OutputStream os = m.getContent(OutputStream.class);
            if (os != osOriginal && os instanceof CachedOutputStream) {
                CachedOutputStream cos = (CachedOutputStream)os;
                if (cos.size() != 0) {
                    cos.writeCacheTo(osOriginal);
                }
            }
        }
    }
    
    private void handleWriteException(Message message, 
                                         Response response, 
                                         OperationResourceInfo ori,
                                         Throwable ex,
                                         Object responseObj,
                                         boolean firstTry) {
        OutputStream out = message.getContent(OutputStream.class);
        if (firstTry) {
            Response excResponse = JAXRSUtils.convertFaultToResponse(ex, message);
            if (excResponse != null) {
                serializeMessage(message, excResponse, ori, false);
                return;
            } else {
                ex.printStackTrace();
            }
        }
        message.put(Message.RESPONSE_CODE, 500);
        writeResponseErrorMessage(out, "SERIALIZE_ERROR", 
                                  responseObj.getClass().getSimpleName()); 
            
    }
    
    
    private void writeResponseErrorMessage(OutputStream out, String errorString, 
                                           String parameter) {
        try {
            org.apache.cxf.common.i18n.Message message = 
                new org.apache.cxf.common.i18n.Message(errorString,
                                                   BUNDLE,
                                                   parameter);
            LOG.warning(message.toString());
            out.write(message.toString().getBytes("UTF-8"));
        } catch (IOException another) {
            // ignore
        }
    }
    
    @SuppressWarnings("unchecked")
    private List<MediaType> computeAvailableContentTypes(Message message, Response response) {
        
        Object contentType = 
            response.getMetadata().getFirst(HttpHeaders.CONTENT_TYPE);
        if (contentType != null) {
            return Collections.singletonList(MediaType.valueOf(contentType.toString()));
        }
        Exchange exchange = message.getExchange();
        List<MediaType> produceTypes = null;
        OperationResourceInfo operation = exchange.get(OperationResourceInfo.class);
        if (operation != null) {
            produceTypes = operation.getProduceTypes();
        } else {
            produceTypes = Collections.singletonList(MediaType.APPLICATION_OCTET_STREAM_TYPE);
        }
        List<MediaType> acceptContentTypes = 
            (List<MediaType>)exchange.get(Message.ACCEPT_CONTENT_TYPE);
        if (acceptContentTypes == null) {
            acceptContentTypes = Collections.singletonList(MediaType.WILDCARD_TYPE);
        }        
        return JAXRSUtils.intersectMimeTypes(acceptContentTypes, produceTypes, true);
        
    }
    
    private Class<?> getRawResponseClass(Object targetObject) {
        if (GenericEntity.class.isAssignableFrom(targetObject.getClass())) {
            return ((GenericEntity)targetObject).getRawType();
        } else {
            return targetObject.getClass();
        }
    }
    
    private Type getGenericResponseType(Method invoked, Object targetObject) {
        if (GenericEntity.class.isAssignableFrom(targetObject.getClass())) {
            return ((GenericEntity)targetObject).getType();
        } else {
            return invoked == null ? targetObject.getClass() : invoked.getGenericReturnType();
        }
    }
    
    private MediaType checkFinalContentType(MediaType mt) {
        if (mt.isWildcardType() || mt.isWildcardSubtype()) {
            return MediaType.APPLICATION_OCTET_STREAM_TYPE;
        } else if (mt.getParameters().containsKey("q")) {
            return MediaType.valueOf(JAXRSUtils.removeMediaTypeParameter(mt, "q"));
        } else {
            return mt;
        }
        
    }
    
    private void setResponseDate(MultivaluedMap<String, Object> headers, boolean firstTry) {
        if (!firstTry) {
            return;
        }
        SimpleDateFormat format = HttpUtils.getHttpDateFormat();
        headers.putSingle(HttpHeaders.DATE, format.format(new Date()));
    }
    
    private boolean isResponseAlreadyHandled(Message m) {
        return isResponseAlreadyCommited(m) || isResponseRedirected(m);
    }
    
    private boolean isResponseAlreadyCommited(Message m) {
        return Boolean.TRUE.equals(m.getExchange().get(AbstractHTTPDestination.RESPONSE_COMMITED));
    }

    private boolean isResponseRedirected(Message outMessage) {
        return Boolean.TRUE.equals(outMessage.get(AbstractHTTPDestination.REQUEST_REDIRECTED));
    }
    
    private void writeResponseToStream(OutputStream os, Object responseObj) {
        try {
            byte[] bytes = responseObj.toString().getBytes("UTF-8");
            os.write(bytes, 0, bytes.length);
        } catch (Exception ex) {
            LOG.severe("Problem with writing the data to the output stream");
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }
    }
}

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