ch.rasc.wampspring.message.WampMessage.java Source code

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Here is the source code for ch.rasc.wampspring.message.WampMessage.java

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/**
 * Copyright 2014-2015 Ralph Schaer <ralphschaer@gmail.com>
 *
 * Licensed 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 ch.rasc.wampspring.message;

/**
 * Base class of the WampMessages
 */
import java.io.IOException;
import java.security.Principal;
import java.util.Map;

import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.handler.annotation.support.DestinationVariableMethodArgumentResolver;
import org.springframework.web.socket.WebSocketSession;

import ch.rasc.wampspring.config.WampSession;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;

public abstract class WampMessage implements Message<Object> {

    protected final static Object EMPTY_OBJECT = new Object();

    private final MutableMessageHeaders messageHeaders = new MutableMessageHeaders();

    WampMessage(WampMessageType type) {
        setHeader(WampMessageHeader.WAMP_MESSAGE_TYPE, type);
    }

    int getTypeId() {
        return getType().getTypeId();
    }

    public WampMessageType getType() {
        return getHeader(WampMessageHeader.WAMP_MESSAGE_TYPE);
    }

    public void setHeader(WampMessageHeader header, Object value) {
        this.messageHeaders.getRawHeaders().put(header.name(), value);
    }

    @SuppressWarnings("unchecked")
    public <T> T getHeader(WampMessageHeader header) {
        return (T) this.messageHeaders.get(header.name());
    }

    public void setDestinationTemplateVariables(Map<String, String> vars) {
        this.messageHeaders.getRawHeaders()
                .put(DestinationVariableMethodArgumentResolver.DESTINATION_TEMPLATE_VARIABLES_HEADER, vars);
    }

    /**
     * Convenient method to retrieve the WebSocket session id.
     */
    public String getWebSocketSessionId() {
        return getHeader(WampMessageHeader.WEBSOCKET_SESSION_ID);
    }

    public void setWebSocketSessionId(String webSocketSessionId) {
        setHeader(WampMessageHeader.WEBSOCKET_SESSION_ID, webSocketSessionId);
    }

    public String getDestination() {
        return null;
    }

    public Principal getPrincipal() {
        return getHeader(WampMessageHeader.PRINCIPAL);
    }

    void setPrincipal(Principal principal) {
        setHeader(WampMessageHeader.PRINCIPAL, principal);
    }

    public WampSession getWampSession() {
        return (WampSession) getHeader(WampMessageHeader.WAMP_SESSION);
    }

    void setWampSession(WampSession wampSession) {
        setHeader(WampMessageHeader.WAMP_SESSION, wampSession);
    }

    @Override
    public Object getPayload() {
        return EMPTY_OBJECT;
    }

    @Override
    public MessageHeaders getHeaders() {
        return this.messageHeaders;
    }

    public static <T extends WampMessage> T fromJson(WebSocketSession session, JsonFactory jsonFactory, String json)
            throws IOException {

        WampSession wampSession = new WampSession(session);

        T newWampMessage = fromJson(jsonFactory, json, wampSession);

        newWampMessage.setWebSocketSessionId(session.getId());
        newWampMessage.setPrincipal(session.getPrincipal());
        newWampMessage.setWampSession(wampSession);

        return newWampMessage;
    }

    public abstract String toJson(JsonFactory jsonFactory) throws IOException;

    public static <T extends WampMessage> T fromJson(JsonFactory jsonFactory, String json) throws IOException {
        return fromJson(jsonFactory, json, null);
    }

    @SuppressWarnings("unchecked")
    public static <T extends WampMessage> T fromJson(JsonFactory jsonFactory, String json, WampSession wampSession)
            throws IOException {

        try (JsonParser jp = jsonFactory.createParser(json)) {
            if (jp.nextToken() != JsonToken.START_ARRAY) {
                throw new IOException("Not a JSON array");
            }
            if (jp.nextToken() != JsonToken.VALUE_NUMBER_INT) {
                throw new IOException("Wrong message format");
            }

            WampMessageType messageType = WampMessageType.fromTypeId(jp.getValueAsInt());

            switch (messageType) {
            case WELCOME:
                return (T) new WelcomeMessage(jp);
            case PREFIX:
                return (T) new PrefixMessage(jp);
            case CALL:
                return (T) new CallMessage(jp, wampSession);
            case CALLRESULT:
                return (T) new CallResultMessage(jp);
            case CALLERROR:
                return (T) new CallErrorMessage(jp);
            case SUBSCRIBE:
                return (T) new SubscribeMessage(jp, wampSession);
            case UNSUBSCRIBE:
                return (T) new UnsubscribeMessage(jp, wampSession);
            case PUBLISH:
                return (T) new PublishMessage(jp, wampSession);
            case EVENT:
                return (T) new EventMessage(jp, wampSession);
            default:
                return null;
            }

        }
    }

    @SuppressWarnings("serial")
    private static class MutableMessageHeaders extends MessageHeaders {

        public MutableMessageHeaders() {
            super(null, MessageHeaders.ID_VALUE_NONE, -1L);
        }

        @Override
        public Map<String, Object> getRawHeaders() {
            return super.getRawHeaders();
        }
    }

    protected String replacePrefix(String uri, WampSession wampSession) {
        if (uri != null && wampSession != null && wampSession.hasPrefixes()) {
            String[] curie = uri.split(":");
            if (curie.length == 2) {
                String prefix = wampSession.getPrefix(curie[0]);
                if (prefix != null) {
                    return prefix + curie[1];
                }
            }
        }
        return uri;
    }

}