com.netflix.exhibitor.core.state.FourLetterWord.java Source code

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Here is the source code for com.netflix.exhibitor.core.state.FourLetterWord.java

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/*
 * Copyright 2012 Netflix, Inc.
 *
 *    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.netflix.exhibitor.core.state;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.io.CharStreams;
import com.netflix.exhibitor.core.config.InstanceConfig;
import com.netflix.exhibitor.core.config.IntConfigs;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.Socket;
import java.util.List;
import java.util.Map;

public class FourLetterWord {
    private final String response;

    public enum Word {
        STAT, RUOK, REQS, DUMP, CONF, CONS, SRVR, WCHS, WCHC, WCHP, MNTR
    }

    public FourLetterWord(Word word, InstanceConfig config, int connectionTimeOutMs) {
        this(word, "localhost", config, connectionTimeOutMs);
    }

    public FourLetterWord(Word word, String hostname, InstanceConfig config, int connectionTimeOutMs) {
        Preconditions.checkNotNull(word);

        String localResponse = "";
        Socket s = null;
        try {
            s = new Socket(hostname, config.getInt(IntConfigs.CLIENT_PORT));
            s.setTcpNoDelay(true);
            s.setSoTimeout(connectionTimeOutMs);

            s.getOutputStream().write(word.name().toLowerCase().getBytes());
            s.getOutputStream().flush();

            localResponse = CharStreams.toString(new InputStreamReader(s.getInputStream()));
        } catch (Exception e) {
            // ignore - treat as server not running
        } finally {
            try {
                if (s != null) {
                    s.close();
                }
            } catch (IOException e) {
                // ignore
            }
        }

        response = localResponse;
    }

    public List<String> getResponseLines() {
        ImmutableList.Builder<String> builder = ImmutableList.builder();
        BufferedReader in = new BufferedReader(new StringReader(response));
        for (;;) {
            try {
                String line = in.readLine();
                if (line == null) {
                    break;
                }
                builder.add(line);
            } catch (IOException ignore) {
                break; // will never happen
            }
        }
        return builder.build();
    }

    public Map<String, String> getResponseMap() {
        ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
        for (String line : getResponseLines()) {
            int colonIndex = line.indexOf(':');
            if (colonIndex > 0) {
                String name = line.substring(0, colonIndex);
                String value = ((colonIndex + 1) < line.length()) ? line.substring(colonIndex + 1) : "";
                builder.put(name.toLowerCase(), value);
            }
        }

        return builder.build();
    }

    public String getResponse() {
        return response;
    }
}