com.datatorrent.stram.client.WebServicesVersionConversion.java Source code

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Here is the source code for com.datatorrent.stram.client.WebServicesVersionConversion.java

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/**
 * 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 com.datatorrent.stram.client;

import java.io.ByteArrayInputStream;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.http.client.utils.URIBuilder;

import com.sun.jersey.api.client.ClientHandlerException;
import com.sun.jersey.api.client.ClientRequest;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.filter.ClientFilter;

import com.datatorrent.stram.webapp.WebServices;

/**
 * <p>WebServicesVersionConversion class.</p>
 *
 * @since 0.9.2
 */
public class WebServicesVersionConversion {
    public interface Converter {
        String convertCommandPath(String path);

        String convertResponse(String path, String response);

    }

    @SuppressWarnings("serial")
    public static class IncompatibleVersionException extends Exception {
        IncompatibleVersionException(String message) {
            super(message);
        }

    }

    public static class VersionConversionFilter extends ClientFilter {
        private final Converter converter;

        public VersionConversionFilter(Converter converter) {
            this.converter = converter;
        }

        @Override
        public ClientResponse handle(ClientRequest cr) throws ClientHandlerException {
            URIBuilder uriBuilder = new URIBuilder(cr.getURI());
            String path = uriBuilder.getPath();
            uriBuilder.setPath(converter.convertCommandPath(path));
            try {
                cr.setURI(uriBuilder.build());
                ClientResponse response = getNext().handle(cr);
                String newEntity = converter.convertResponse(path, response.getEntity(String.class));
                response.setEntityInputStream(new ByteArrayInputStream(newEntity.getBytes()));
                return response;
            } catch (Exception ex) {
                throw new ClientHandlerException(ex);
            }
        }

    }

    private static final Logger LOG = LoggerFactory.getLogger(WebServicesVersionConversion.class);

    public static boolean isVersionCompatible(String version) {
        if (!version.startsWith("v")) {
            LOG.error("Version {} is invalid", version);
            return false;
        }
        version = version.substring(1);
        int majorVersion = Integer.valueOf(version.split("\\.")[0]);
        int thisVersion = Integer.valueOf(WebServices.VERSION.substring(1).split("\\.")[0]);
        if (majorVersion > thisVersion) {
            LOG.warn("Future stram version {} is incompatible. Please upgrade the DataTorrent Gateway and/or CLI",
                    majorVersion);
            return false;
        }
        // Add old versions that are not supported here in the future

        return true;
    }

    public static Converter getConverter(String version) throws IncompatibleVersionException {
        if (!isVersionCompatible(version)) {
            throw new IncompatibleVersionException("Stram version " + version
                    + " is incompatible with the current build (" + WebServices.VERSION + ")");
        }
        // Add old versions that ARE supported here in the future
        if (version.equals("v1")) {
            return new Converter() {

                @Override
                public String convertCommandPath(String path) {
                    return path.replaceFirst("/ws/v2/", "/ws/v1/");
                }

                @Override
                public String convertResponse(String path, String response) {
                    return response;
                }
            };
        }
        return null;
    }

}