# JsonStreamBuilder.java

    /**
     *  Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
     *
     *  WSO2 Inc. 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.synapse.commons.json;

    import org.apache.axiom.om.OMAbstractFactory;
    import org.apache.axiom.om.OMElement;
    import org.apache.axiom.soap.SOAPEnvelope;
    import org.apache.axiom.soap.SOAPFactory;
    import org.apache.axis2.AxisFault;
    import org.apache.axis2.addressing.EndpointReference;
    import org.apache.axis2.builder.Builder;
    import org.apache.axis2.context.MessageContext;
    import org.apache.axis2.transport.http.util.URIEncoderDecoder;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

    import java.io.*;

    public final class JsonStreamBuilder implements Builder {

        private static final Log logger = LogFactory.getLog(JsonStreamBuilder.class.getName());

        public OMElement processDocument(InputStream inputStream, String s,
                                         MessageContext messageContext) throws AxisFault {

            if (inputStream != null) {
                OMElement element = JsonUtil.getNewJsonPayload(messageContext, inputStream, false, false);
                if (element != null) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("#processDocument. Built JSON payload from JSON stream. MessageID: " + messageContext.getMessageID());
                    }
                    return element;
                }
            } else {
                EndpointReference endpointReference = messageContext.getTo();
                if (endpointReference == null) {
                    logger.error("#processDocument. Cannot build payload without a valid EPR. MessageID: " + messageContext.getMessageID());
                    throw new AxisFault("Cannot build payload without a valid EPR.");
                }
                String requestURL;
                try {
                    requestURL = URIEncoderDecoder.decode(endpointReference.getAddress());
                } catch (UnsupportedEncodingException e) {
                    logger.error("#processDocument. Could not decode request URL. MessageID: " + messageContext.getMessageID());
                    throw new AxisFault("Could not decode request URL.", e);
                }
                String jsonString;
                int index;
                //As the message is received through GET, check for "=" sign and consider the second
                //half as the incoming JSON message
                if ((index = requestURL.indexOf('=')) > 0) {
                    jsonString = requestURL.substring(index + 1);
                    messageContext.setProperty(Constants.JSON_STRING, jsonString);
                    ByteArrayInputStream is = new ByteArrayInputStream(jsonString.getBytes());
                    return processDocument(is, s, messageContext);
                } else {
                    messageContext.setProperty(Constants.JSON_STRING, null);
                }
            }
            if (logger.isDebugEnabled()) {
                logger.debug("#processDocument. No JSON payload found in request. MessageID: " + messageContext.getMessageID());
            }
            SOAPFactory factory = OMAbstractFactory.getSOAP12Factory();
            return factory.getDefaultEnvelope();
        }
    }