com.google.shipshape.util.rpc.HttpTransport.java Source code

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Here is the source code for com.google.shipshape.util.rpc.HttpTransport.java

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/*
 * Copyright 2014 Google Inc. All rights reserved.
 *
 * 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.google.shipshape.util.rpc;

import static com.google.shipshape.util.rpc.HttpServerFrontend.DEFAULT_CHARSET;

import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.gson.Gson;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/** K-RPC over HTTP {@link Connection.Transport}. */
public class HttpTransport implements Connection.Transport {
    private static final Pattern ADDRESS_PATTERN = Pattern.compile("\\s*(.*?):(\\d+)\\s*");

    private final URL url;

    private HttpTransport(URL url) {
        Preconditions.checkNotNull(url, "url must be non-null");
        this.url = url;
    }

    public static Connection newHttpConnection(URL url) {
        return new Connection(new HttpTransport(url));
    }

    /** Returns a {@link Connection} to the given host over HTTP. */
    public static Connection newHttpConnection(String host, int port) {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(host), "host must be non-empty");
        Preconditions.checkArgument(port > 0, "port must be positive");
        try {
            return newHttpConnection(new URL("http", host, port, "/"));
        } catch (MalformedURLException e) {
            throw new IllegalArgumentException(e);
        }
    }

    /** Returns a {@link Connection} from a "host:port" formatted {@link String}. */
    public static Connection parse(String address) {
        Matcher m = ADDRESS_PATTERN.matcher(address);
        Preconditions.checkArgument(m.matches(), "serverAddress does not match host:port format");
        return newHttpConnection(m.group(1), Integer.parseInt(m.group(2)));
    }

    @Override
    public Reader sendRequest(Gson gson, Protocol.Request request) throws IOException {
        String json = gson.toJson(request);

        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Encoding", "application/json; charset=" + DEFAULT_CHARSET);
        connection.setRequestProperty("Content-Length", "" + json.length());
        connection.setDoOutput(true);
        connection.setDoInput(true);
        connection.setInstanceFollowRedirects(false);
        connection.setUseCaches(false);

        try (OutputStream stream = connection.getOutputStream();
                OutputStreamWriter writer = new OutputStreamWriter(stream, DEFAULT_CHARSET)) {
            writer.write(json);
        }

        return new InputStreamReader(connection.getInputStream(), DEFAULT_CHARSET);
    }
}