summaryrefslogtreecommitdiffstats
path: root/sca-java-2.x/trunk/modules/binding-comet-runtime/src/main/java/org/apache/tuscany/sca/binding/comet/runtime/handler/CometBindingHandler.java
blob: c2d21818148608875ae33246b22e5b2b45ea6a6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/*
 * 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.tuscany.sca.binding.comet.runtime.handler;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;

import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;

import org.apache.tuscany.sca.assembly.EndpointReference;
import org.apache.tuscany.sca.binding.comet.runtime.manager.CometEndpointManager;
import org.apache.tuscany.sca.binding.comet.runtime.manager.CometOperationManager;
import org.apache.tuscany.sca.binding.comet.runtime.manager.CometSessionManager;
import org.apache.tuscany.sca.core.assembly.impl.RuntimeEndpointImpl;
import org.apache.tuscany.sca.core.assembly.impl.RuntimeEndpointReferenceImpl;
import org.apache.tuscany.sca.core.invocation.Constants;
import org.apache.tuscany.sca.core.invocation.impl.MessageImpl;
import org.apache.tuscany.sca.interfacedef.DataType;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.invocation.Message;
import org.apache.tuscany.sca.runtime.RuntimeEndpoint;
import org.atmosphere.cpr.Broadcaster;
import org.atmosphere.jersey.JerseyBroadcaster;
import org.atmosphere.jersey.SuspendResponse;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

@Path("/")
public class CometBindingHandler {

    private static Gson gson = new GsonBuilder().serializeNulls().create();

    @GET
    @Path("/connect")
    public SuspendResponse<String> connect(@QueryParam("sessionId") String sessionId) {
        System.out.println("-- connect -- Session Id: " + sessionId);
        Broadcaster broadcaster = CometSessionManager.get(sessionId);
        if (broadcaster == null) {
            broadcaster = new JerseyBroadcaster(sessionId);
            CometSessionManager.add(sessionId, broadcaster);
        }
        return new SuspendResponse.SuspendResponseBuilder<String>().broadcaster(broadcaster).outputComments(true)
                .build();
    }

    @POST
    @Path("/{service}/{method}")
    public void handleRequest(@PathParam("service") String service, @PathParam("method") String method,
            @FormParam("sessionId") String sessionId, @FormParam("callbackMethod") String callbackMethod,
            @FormParam("params") String jsonData) throws InvocationTargetException {
        System.out.println("-- handleRequest -- Session Id: " + sessionId);
        String url = "/" + service + "/" + method;
        RuntimeEndpoint wire = CometEndpointManager.get(url);
        Operation operation = CometOperationManager.get(url);

        final Object[] args = decodeJsonDataForOperation(jsonData, operation);
        Message msg = createMessageWithMockedCometReference(args, sessionId, callbackMethod);
        boolean isVoidReturnType = operation.getOutputType().getLogical().isEmpty();
        if (!isVoidReturnType) {
            Object response = wire.invoke(operation, args);
            Broadcaster broadcaster = CometSessionManager.get(sessionId);
            broadcaster.broadcast(callbackMethod + "($.secureEvalJSON('" + gson.toJson(response) + "'))");
            if (broadcaster.getAtmosphereResources().isEmpty()) {
                CometSessionManager.remove(sessionId);
            }
        } else {
            wire.invoke(operation, msg);
        }
    }

    /**
     * Convert request parameters from JSON to operation parameter types.
     * 
     * @param jsonData
     * @param operation
     * @return
     */
    private Object[] decodeJsonDataForOperation(String jsonData, Operation operation) {
        Object[] args = new Object[operation.getInputType().getLogical().size()];
        final String[] json = this.parseArray(jsonData);
        int index = 0;
        // convert each argument to the corresponding class
        for (final DataType<?> dataType : operation.getInputType().getLogical()) {
            args[index] = gson.fromJson(json[index], dataType.getPhysical());
            index++;
        }
        return args;
    }

    /**
     * Creates the message to be sent with a mocked EndpointReference in the
     * 'from' field as the request comes from a browser (there is no actual
     * comet reference running in a controlled environment).
     * 
     * @param args
     * @param callbackMethod
     * @return
     */
    private Message createMessageWithMockedCometReference(Object[] args, String sessionId, String callbackMethod) {
        Message msg = new MessageImpl();
        msg.getHeaders().put(Constants.MESSAGE_ID, sessionId);
        msg.setBody(args);
        EndpointReference re = new RuntimeEndpointReferenceImpl();
        RuntimeEndpointImpl callbackEndpoint = new RuntimeEndpointImpl();
        callbackEndpoint.setURI(callbackMethod);
        re.setCallbackEndpoint(callbackEndpoint);
        msg.setFrom(re);
        return msg;
    }

    /**
     * Parse the JSON array containing the arguments for the method call in
     * order to avoid converting JSON to Object[]. Converting each object
     * separately to it's corresponding type avoids type mismatch problems at
     * service invocation.
     * 
     * @param jsonArray
     *            the JSON array
     * @return an array of JSON formatted objects
     */
    private String[] parseArray(final String jsonArray) {
        final List<String> objects = new ArrayList<String>();
        int bracketNum = 0;
        int parNum = 0;
        int startPos = 1;
        for (int i = 0; i < jsonArray.length(); i++) {
            switch (jsonArray.charAt(i)) {
            case '{':
                bracketNum++;
                break;
            case '}':
                bracketNum--;
                break;
            case '[':
                parNum++;
                break;
            case ']':
                parNum--;
                break;
            case ',':
                if ((bracketNum == 0) && (parNum == 1)) {
                    objects.add(jsonArray.substring(startPos, i));
                    startPos = i + 1;
                }
            }
        }
        // add last object
        objects.add(jsonArray.substring(startPos, jsonArray.length() - 1));
        return objects.toArray(new String[] {});
    }

}