io.soliton.protobuf.json.JsonRpcRequest.java Source code

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Here is the source code for io.soliton.protobuf.json.JsonRpcRequest.java

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/**
 * Copyright 2013 Julien Silland
 *
 * 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 io.soliton.protobuf.json;

import io.soliton.protobuf.ServerMethod;
import io.soliton.protobuf.Service;
import io.soliton.protobuf.ServiceGroup;

import com.google.common.base.Function;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;
import com.google.protobuf.Message;
import io.netty.handler.codec.http.HttpResponseStatus;

import java.util.List;

/**
 * Structured representation of a JSON-RPC request.
 *
 * @author Julien Silland (julien@soliton.io)
 */
class JsonRpcRequest {

    private static final Joiner DOT_JOINER = Joiner.on('.');
    private static final Splitter DOT_SPLITTER = Splitter.on('.').trimResults().omitEmptyStrings();

    private final String service;
    private final String method;
    private final JsonElement id;
    private final JsonObject parameter;

    /**
     * Exhaustive constructor
     *
     * @param service the service this call is targeting
     * @param method the method this call is targeting
     * @param id the generic identifier of the request, as set by the client
     * @param parameter the sole parameter of this call
     */
    public JsonRpcRequest(String service, String method, JsonElement id, JsonObject parameter) {
        this.service = service;
        this.method = method;
        this.id = id;
        this.parameter = parameter;
    }

    public String service() {
        return service;
    }

    public String method() {
        return method;
    }

    public JsonElement id() {
        return id;
    }

    public JsonObject parameter() {
        return parameter;
    }

    public JsonObject toJson() {
        JsonObject request = new JsonObject();
        request.add(JsonRpcProtocol.ID, id());
        request.add(JsonRpcProtocol.METHOD, new JsonPrimitive(DOT_JOINER.join(service(), method())));
        JsonArray params = new JsonArray();
        params.add(parameter());
        request.add(JsonRpcProtocol.PARAMETERS, params);
        return request;
    }

    public static JsonRpcRequest fromJson(JsonElement root) throws JsonRpcError {
        if (!root.isJsonObject()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Received payload is not a JSON Object");
        }

        JsonObject request = root.getAsJsonObject();
        JsonElement id = request.get(JsonRpcProtocol.ID);
        JsonElement methodNameElement = request.get(JsonRpcProtocol.METHOD);
        JsonElement paramsElement = request.get(JsonRpcProtocol.PARAMETERS);

        if (id == null) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Malformed request, missing 'id' property");
        }

        if (methodNameElement == null) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Malformed request, missing 'method' property");
        }

        if (paramsElement == null) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Malformed request, missing 'params' property");
        }

        if (!methodNameElement.isJsonPrimitive()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Method name is not a JSON primitive");
        }

        JsonPrimitive methodName = methodNameElement.getAsJsonPrimitive();
        if (!methodName.isString()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Method name is not a string");
        }

        if (!paramsElement.isJsonArray()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'params' property is not an array");
        }

        JsonArray params = paramsElement.getAsJsonArray();
        if (params.size() != 1) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'params' property is not an array");
        }

        JsonElement paramElement = params.get(0);
        if (!paramElement.isJsonObject()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "Parameter is not an object");
        }

        JsonObject parameter = paramElement.getAsJsonObject();
        List<String> serviceAndMethod = Lists.newArrayList(DOT_SPLITTER.split(methodName.getAsString()));

        String methodNameString = methodName.getAsString();
        int dotIndex = methodNameString.lastIndexOf('.');

        if (dotIndex < 0) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'method' property is not properly formatted");
        }

        if (dotIndex == methodNameString.length() - 1) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'method' property is not properly formatted");
        }

        String service = methodNameString.substring(0, dotIndex);
        String method = methodNameString.substring(dotIndex + 1);

        if (service.isEmpty() || method.isEmpty()) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'method' property is not properly formatted");
        }

        if (serviceAndMethod.size() < 2) {
            throw new JsonRpcError(HttpResponseStatus.BAD_REQUEST, "'method' property is not properly formatted");
        }

        return new JsonRpcRequest(service, method, id, parameter);
    }
}