JsonHubProtocol.java Source code

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Here is the source code for JsonHubProtocol.java

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// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

import com.google.gson.Gson;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import java.util.ArrayList;
import java.util.List;

public class JsonHubProtocol implements HubProtocol {
    private final JsonParser jsonParser = new JsonParser();
    private final Gson gson = new Gson();
    private static final String RECORD_SEPARATOR = "\u001e";

    @Override
    public String getName() {
        return "json";
    }

    @Override
    public int getVersion() {
        return 1;
    }

    @Override
    public TransferFormat getTransferFormat() {
        return TransferFormat.Text;
    }

    @Override
    public HubMessage[] parseMessages(String payload) {
        String[] messages = payload.split(RECORD_SEPARATOR);
        List<HubMessage> hubMessages = new ArrayList<>();
        for (String splitMessage : messages) {

            JsonObject jsonMessage = jsonParser.parse(splitMessage).getAsJsonObject();
            HubMessageType messageType = HubMessageType.values()[jsonMessage.get("type").getAsInt() - 1];
            switch (messageType) {
            case INVOCATION:
                //Invocation Message
                String target = jsonMessage.get("target").getAsString();
                JsonElement args = jsonMessage.get("arguments");
                hubMessages.add(new InvocationMessage(target, new Object[] { args }));
                break;
            case STREAM_ITEM:
                throw new UnsupportedOperationException("Support for streaming is not yet available");
            case COMPLETION:
                //Don't care yet
                break;
            case STREAM_INVOCATION:
                //Don't care yet;
                throw new UnsupportedOperationException("Support for streaming is not yet available");
            case CANCEL_INVOCATION:
                // Not tracking invocations yet
                break;
            case PING:
                //Ping
                hubMessages.add(new PingMessage());
                break;
            case CLOSE:
                //Don't care yet;
                break;
            }
        }
        return hubMessages.toArray(new HubMessage[hubMessages.size()]);
    }

    @Override
    public String writeMessage(HubMessage hubMessage) {
        return gson.toJson(hubMessage) + RECORD_SEPARATOR;
    }
}