Apache CXF example source code file (JSONProvider.java)

This example Apache CXF source code file (JSONProvider.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, class, exception, exception, inputstream, inputstream, io, jaxbelement, object, object, outputstream, qname, reflection, string, string, threading, threads, type, util, webapplicationexception

The Apache CXF JSONProvider.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.provider;


import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.SequenceInputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Collection;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.Provider;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.apache.cxf.jaxrs.ext.MessageContext;
import org.apache.cxf.jaxrs.utils.HttpUtils;
import org.apache.cxf.jaxrs.utils.InjectionUtils;
import org.apache.cxf.jaxrs.utils.schemas.SchemaHandler;
import org.codehaus.jettison.mapped.Configuration;
import org.codehaus.jettison.mapped.SimpleConverter;
import org.codehaus.jettison.mapped.TypeConverter;

@Produces("application/json")
@Consumes("application/json")
@Provider
public class JSONProvider extends AbstractJAXBProvider  {
    
    private static final String MAPPED_CONVENTION = "mapped";
    private static final String BADGER_FISH_CONVENTION = "badgerfish";
    
    private ConcurrentHashMap<String, String> namespaceMap = 
        new ConcurrentHashMap<String, String>();
    private boolean serializeAsArray;
    private List<String> arrayKeys;
    private boolean unwrapped;
    private String wrapperName;
    private Map<String, String> wrapperMap;
    private boolean dropRootElement;
    private boolean dropCollectionWrapperElement;
    private boolean ignoreMixedContent; 
    private boolean writeXsiType = true;
    private boolean readXsiType = true;
    private boolean ignoreNamespaces;
    private String convention = MAPPED_CONVENTION;
    private TypeConverter typeConverter;
    
    public void setConvention(String value) {
        if (!MAPPED_CONVENTION.equals(value) && !BADGER_FISH_CONVENTION.equals(value)) {
            throw new IllegalArgumentException("Unsupported convention \"" + value);
        }
        convention = value;
    }
    
    public void setConvertTypesToStrings(boolean convert) {
        if (convert) {
            this.setTypeConverter(new SimpleConverter());
        }
    }
    
    public void setTypeConverter(TypeConverter converter) {
        this.typeConverter = converter;
    }
    
    public void setIgnoreNamespaces(boolean ignoreNamespaces) {
        this.ignoreNamespaces = ignoreNamespaces;
    }
    
    @Context
    public void setMessageContext(MessageContext mc) {
        super.setContext(mc);
    }
    
    public void setDropRootElement(boolean drop) {
        this.dropRootElement = drop;
    }
    
    public void setDropCollectionWrapperElement(boolean drop) {
        this.dropCollectionWrapperElement = drop;
    }
    
    public void setIgnoreMixedContent(boolean ignore) {
        this.ignoreMixedContent = ignore;
    }
    
    public void setSupportUnwrapped(boolean unwrap) {
        this.unwrapped = unwrap;
    }
    
    public void setWrapperName(String wName) {
        wrapperName = wName;
    }
    
    public void setWrapperMap(Map<String, String> map) {
        wrapperMap = map;
    }
    
    public void setEnableBuffering(boolean enableBuf) {
        super.setEnableBuffering(enableBuf);
    }
    
    public void setConsumeMediaTypes(List<String> types) {
        super.setConsumeMediaTypes(types);
    }
    
    public void setProduceMediaTypes(List<String> types) {
        super.setProduceMediaTypes(types);
    }
    
    public void setSchemas(List<String> locations) {
        super.setSchemaLocations(locations);
    }
    
    public void setSchemaHandler(SchemaHandler handler) {
        super.setSchema(handler.getSchema());
    }
    
    public void setSerializeAsArray(boolean asArray) {
        this.serializeAsArray = asArray;
    }
    
    public void setArrayKeys(List<String> keys) {
        this.arrayKeys = keys;
    }
    
    public void setNamespaceMap(Map<String, String> namespaceMap) {
        this.namespaceMap.putAll(namespaceMap);
    }

    public Object readFrom(Class<Object> type, Type genericType, Annotation[] anns, MediaType mt, 
        MultivaluedMap<String, String> headers, InputStream is) 
        throws IOException {
        
        try {
            Class<?> theType = getActualType(type, genericType, anns);
            Unmarshaller unmarshaller = createUnmarshaller(theType, genericType);
            
            InputStream realStream = getInputStream(type, genericType, is);
            XMLStreamReader xsw = createReader(type, realStream);
            
            Object response = null;
            if (JAXBElement.class.isAssignableFrom(type) 
                || unmarshalAsJaxbElement
                || jaxbElementClassMap != null && jaxbElementClassMap.containsKey(theType.getName())) {
                response = unmarshaller.unmarshal(xsw, theType);
            } else {
                response = unmarshaller.unmarshal(xsw);
            }
            if (response instanceof JAXBElement && !JAXBElement.class.isAssignableFrom(type)) {
                response = ((JAXBElement)response).getValue();    
            }
            response = checkAdapter(response, type, anns, false);
            return response;
            
        } catch (JAXBException e) {
            handleJAXBException(e);
        } catch (XMLStreamException e) {
            throw new WebApplicationException(e);
        } catch (WebApplicationException e) {
            throw e;
        } catch (Exception e) {
            throw new WebApplicationException(e);
        }
        // unreachable
        return null;
    }

    protected XMLStreamReader createReader(Class<?> type, InputStream is) 
        throws Exception {
        if (BADGER_FISH_CONVENTION.equals(convention)) {
            return JSONUtils.createBadgerFishReader(is);
        } else {
            XMLStreamReader reader = JSONUtils.createStreamReader(is, readXsiType, namespaceMap);
            return createTransformReaderIfNeeded(reader, is);
        }
    }
    
    protected InputStream getInputStream(Class<Object> cls, Type type, InputStream is) throws Exception {
        if (unwrapped) {
            String rootName = getRootName(cls, type);
            InputStream isBefore = new ByteArrayInputStream(rootName.getBytes());
            String after = "}";
            InputStream isAfter = new ByteArrayInputStream(after.getBytes());
            final InputStream[] streams = new InputStream[]{isBefore, is, isAfter};
            
            Enumeration<InputStream> list = new Enumeration() {
                private int index; 
                public boolean hasMoreElements() {
                    return index < streams.length;
                }

                public InputStream nextElement() {
                    return streams[index++];
                }  
                
            };
            return new SequenceInputStream(list);
        } else {
            return is;
        }
                 
    }
    
    protected String getRootName(Class<Object> cls, Type type) throws Exception {
        String name = null;
        if (wrapperName != null) {
            name = wrapperName;
        } else if (wrapperMap != null) {
            name = wrapperMap.get(cls.getName());
        }
        if (name == null) {
            QName qname = getQName(cls, type, null, false);
            if (qname != null) {
                name = qname.getLocalPart();
                String prefix = qname.getPrefix();
                if (prefix.length() > 0) {
                    name = prefix + "." + name;
                }
            }
        }
        
        if (name == null) {
            throw new WebApplicationException(500);
        }
        
        return "{\"" + name + "\":";
    }
    
    public void writeTo(Object obj, Class<?> cls, Type genericType, Annotation[] anns,  
        MediaType m, MultivaluedMap<String, Object> headers, OutputStream os)
        throws IOException {
        try {
            
            Object actualObject = checkAdapter(obj, cls, anns, true);
            Class<?> actualClass = obj != actualObject ? actualObject.getClass() : cls;
            if (cls == genericType) {
                genericType = actualClass;
            }
            String encoding = HttpUtils.getSetEncoding(m, headers, "UTF-8");
            
            if (InjectionUtils.isSupportedCollectionOrArray(actualClass)) {
                actualClass = InjectionUtils.getActualType(genericType);
                actualClass = getActualType(actualClass, genericType, anns);
                marshalCollection(cls, actualObject, actualClass, genericType, encoding, os, m);
            } else {
                marshal(actualObject, actualClass, genericType, encoding, os);
            }
            
        } catch (JAXBException e) {
            handleJAXBException(e);
        } catch (XMLStreamException e) {
            throw new WebApplicationException(e);
        } catch (Exception e) {
            throw new WebApplicationException(e);
        }
    }

    protected void marshalCollection(Class<?> originalCls, Object actualObject, Class actualClass,
                                     Type genericType, String encoding, OutputStream os, MediaType m) 
        throws Exception {
        
        String startTag = null;
        String endTag = null;
        if (!dropCollectionWrapperElement) {
            QName qname = getCollectionWrapperQName(actualClass, genericType, actualObject, false);
            if (qname == null) {
                String message = new org.apache.cxf.common.i18n.Message("NO_COLLECTION_ROOT", 
                                                                        BUNDLE).toString();
                throw new WebApplicationException(Response.serverError()
                                                  .entity(message).build());
            }
            if (qname.getNamespaceURI().length() > 0) {
                startTag = "{\"ns1." + qname.getLocalPart() + "\":[";
            } else {
                startTag = "{\"" + qname.getLocalPart() + "\":[";
            }
            endTag = "]}";
        } else if (serializeAsArray) {
            startTag = "[";
            endTag = "]";
        } else {
            startTag = "{";
            endTag = "}";
        }
        os.write(startTag.getBytes());
        Object[] arr = originalCls.isArray() ? (Object[])actualObject : ((Collection)actualObject).toArray();
        for (int i = 0; i < arr.length; i++) {
            Object obj = convertToJaxbElementIfNeeded(arr[i], actualClass, genericType);
            Class<?> cls = actualClass;
            if (obj instanceof JAXBElement && actualClass != JAXBElement.class) {
                cls = JAXBElement.class;
            }
            Marshaller ms = createMarshaller(obj, cls, genericType, encoding);
            marshal(ms, obj, cls, genericType, encoding, os, true);
            if (i + 1 < arr.length) {
                os.write(",".getBytes());
            }
        }
        os.write(endTag.getBytes());
    }
    
    protected void marshal(Marshaller ms, Object actualObject, Class<?> actualClass, 
                  Type genericType, String enc, OutputStream os, boolean isCollection) throws Exception {
        
        XMLStreamWriter writer = createWriter(actualObject, actualClass, genericType, enc, 
                                              os, isCollection);
        ms.marshal(actualObject, writer);
        writer.close();
    }
    
    protected XMLStreamWriter createWriter(Object actualObject, Class<?> actualClass, 
        Type genericType, String enc, OutputStream os, boolean isCollection) throws Exception {
        
        if (BADGER_FISH_CONVENTION.equals(convention)) {
            return JSONUtils.createBadgerFishWriter(os);
        }
        
        QName qname = getQName(actualClass, genericType, actualObject, true);
        
        Configuration config = 
            JSONUtils.createConfiguration(namespaceMap, writeXsiType && !ignoreNamespaces, typeConverter);
        
        XMLStreamWriter writer = JSONUtils.createStreamWriter(os, qname, 
             writeXsiType && !ignoreNamespaces, config, serializeAsArray, arrayKeys,
             isCollection || dropRootElement);
        writer = JSONUtils.createIgnoreMixedContentWriterIfNeeded(writer, ignoreMixedContent);
        writer = JSONUtils.createIgnoreNsWriterIfNeeded(writer, ignoreNamespaces);
        return createTransformWriterIfNeeded(writer, os);
    }
    
    protected void marshal(Object actualObject, Class<?> actualClass, 
                           Type genericType, String enc, OutputStream os) throws Exception {
        
        actualObject = convertToJaxbElementIfNeeded(actualObject, actualClass, genericType);
        if (actualObject instanceof JAXBElement && actualClass != JAXBElement.class) {
            actualClass = JAXBElement.class;
        }
        
        Marshaller ms = createMarshaller(actualObject, actualClass, genericType, enc);
        marshal(ms, actualObject, actualClass, genericType, enc, os, false);
    }
    
    private QName getQName(Class<?> cls, Type type, Object object, boolean allocatePrefix) 
        throws Exception {
        QName qname = getJaxbQName(cls, type, object, false);
        if (qname != null) {
            String prefix = getPrefix(qname.getNamespaceURI(), allocatePrefix);
            return new QName(qname.getNamespaceURI(), qname.getLocalPart(), prefix);
        }
        return null;
    }
    
    private String getPrefix(String namespace, boolean allocatePrefix) {
        String prefix = namespaceMap.get(namespace);
        if (prefix == null) {
            if (allocatePrefix && namespace.length() > 0) {
                prefix = "ns" + (namespaceMap.size() + 1);
                namespaceMap.put(namespace, prefix);
            } else {
                prefix = "";
            }
        }
        return prefix;
    }
    
    public void setWriteXsiType(boolean writeXsiType) {
        this.writeXsiType = writeXsiType;
    }
    
    public void setReadXsiType(boolean readXsiType) {
        this.readXsiType = readXsiType;
    }

}