com.seleritycorp.common.base.coreservices.RawCoreServiceClient.java Source code

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Here is the source code for com.seleritycorp.common.base.coreservices.RawCoreServiceClient.java

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/*
 * Copyright (C) 2016 Selerity, Inc. (support@seleritycorp.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 com.seleritycorp.common.base.coreservices;

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

import com.seleritycorp.common.base.config.ApplicationConfig;
import com.seleritycorp.common.base.config.Config;
import com.seleritycorp.common.base.config.ConfigUtils;
import com.seleritycorp.common.base.logging.Log;
import com.seleritycorp.common.base.logging.LogFactory;
import com.seleritycorp.common.base.meta.MetaDataFormatter;
import com.seleritycorp.common.base.uuid.UuidGenerator;
import org.apache.commons.io.IOUtils;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.TimeUnit;

import javax.inject.Inject;
import javax.inject.Singleton;

@Singleton
public class RawCoreServiceClient {
    private static final Log log = LogFactory.getLog(RawCoreServiceClient.class);

    private final UuidGenerator uuidGenerator;
    private final URL apiUrl;
    private final int timeoutMillis;
    private final String user;
    private final String client;

    /**
     * Creates a raw client for CoreService calls.
     * 
     * @param appConfig The application config to use.
     * @param uuidGenerator Used for request ids.
     * @param metaDataFormatter Formatter for the used user agent.
     * @throws MalformedURLException if the CoreServices URL is malformed
     */
    @Inject
    public RawCoreServiceClient(@ApplicationConfig Config appConfig, UuidGenerator uuidGenerator,
            MetaDataFormatter metaDataFormatter) throws MalformedURLException {
        this.uuidGenerator = uuidGenerator;
        Config config = ConfigUtils.subconfig(appConfig, "CoreServices");
        apiUrl = new URL(config.get("url"));
        this.user = config.get("user");

        this.timeoutMillis = (int) config.getDurationMillis("timeout", 300, TimeUnit.SECONDS);

        this.client = metaDataFormatter.getUserAgent();
    }

    private String getRawResponse(String rawRequest, int timeoutMillis) throws IOException {
        URLConnection connection = apiUrl.openConnection();
        connection.setRequestProperty("Accept", "text/plain");
        connection.setRequestProperty("Content-type", "application/json");
        connection.setRequestProperty("User-Agent", client);
        connection.setDoOutput(true);
        connection.setReadTimeout(timeoutMillis);

        final OutputStream out = connection.getOutputStream();
        out.write(rawRequest.getBytes(StandardCharsets.UTF_8));
        out.flush();
        out.close();

        log.debug("wrote request " + rawRequest + " (timeout wanted: " + timeoutMillis + ", actual: "
                + connection.getReadTimeout() + ")");

        String response = null;
        try (final InputStream in = connection.getInputStream()) {
            response = IOUtils.toString(in, StandardCharsets.UTF_8);
        }

        return response;
    }

    public JsonElement call(String method, JsonElement params, int timeout) throws IOException, CallErrorException {
        return call(method, params, null, -1);
    }

    JsonElement call(String method, JsonElement params, String token, int timeoutMillis)
            throws IOException, CallErrorException {
        JsonObject header = new JsonObject();
        header.addProperty("user", user);
        if (token != null) {
            header.addProperty("token", token);
        }
        header.addProperty("client", client);

        JsonObject request = new JsonObject();
        request.addProperty("id", uuidGenerator.generate().toString());
        request.addProperty("method", method);
        request.add("params", params);
        request.add("header", header);

        final int effectiveTimeoutMillis = (timeoutMillis > 0) ? timeoutMillis : this.timeoutMillis;

        final String responseString = getRawResponse(request.toString(), effectiveTimeoutMillis);

        final JsonParser parser = new JsonParser();
        final JsonObject responseObj = parser.parse(responseString).getAsJsonObject();

        final JsonElement error = responseObj.get("error");
        if (error != null && !error.isJsonNull()) {
            throw new CallErrorException("Error: " + error.toString());
        }
        return responseObj.get("result");
    }
}