org.alfresco.cacheserver.CacheServerIdentityImpl.java Source code

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Here is the source code for org.alfresco.cacheserver.CacheServerIdentityImpl.java

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/*
 * Copyright 2015 Alfresco Software, Ltd.  All rights reserved.
 *
 * License rights for this program may be obtained from Alfresco Software, Ltd. 
 * pursuant to a written agreement and any use of this program without such an 
 * agreement is prohibited. 
 */
package org.alfresco.cacheserver;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;

import org.alfresco.util.GUID;
import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

/**
 * 
 * @author sglover
 *
 */
public class CacheServerIdentityImpl implements CacheServerIdentity {
    private static Log logger = LogFactory.getLog(CacheServerIdentityImpl.class);

    private String id;
    private String hostname;
    private int port;

    private String dataFilename = "cacheserver.json";

    public CacheServerIdentityImpl(String hostname, int port, String dataFilename) {
        this.hostname = hostname;
        this.port = port;
        this.dataFilename = dataFilename;

        File dataFile = dataFile();

        try {
            Data data = readData();
            this.id = data.getId();
        } catch (IOException e) {
            logger.error("Unable to create data file " + dataFile, e);
            throw new RuntimeException("Unable to create data file " + dataFile, e);
        }
    }

    private File dataFile() {
        //      File tmpDir = TempFileProvider.getTempDir();
        //      File dataFile = new File(tmpDir, dataFilename);
        File dataFile = new File(dataFilename);
        return dataFile;
    }

    @SuppressWarnings("unchecked")
    private JSONObject toJSON(Data data) {
        String id = data.getId();
        JSONObject ret = new JSONObject();
        ret.put("cacheServerId", id);
        return ret;
    }

    private Data fromJSON(JSONObject syncDataObject) {
        String id = (String) syncDataObject.get("cacheServerId");
        Data ret = new Data(id);
        return ret;
    }

    private Data readData() throws IOException {
        Data data = null;
        File dataFile = dataFile();

        logger.debug("Reading data from file " + dataFile.getAbsolutePath());

        if (dataFile.exists()) {
            try {
                BufferedInputStream in = new BufferedInputStream(new FileInputStream(dataFile));
                try {
                    String string = IOUtils.toString(in, "UTF-8");
                    JSONParser parser = new JSONParser();
                    JSONObject json = (JSONObject) parser.parse(string);
                    data = fromJSON(json);
                } finally {
                    if (in != null) {
                        in.close();
                    }
                }
            } catch (IOException | ParseException e) {
                // fall back - try to re-create re-create
                data = createData(dataFile);
            }
        } else {
            data = createData(dataFile);
        }

        logger.debug("Data " + data);

        return data;
    }

    private Data createData(File syncFile) throws IOException {
        String id = GUID.generate();
        Data data = new Data(id);
        JSONObject dataObject = toJSON(data);

        Writer writer = new FileWriter(syncFile);
        try {
            dataObject.writeJSONString(writer);
        } finally {
            if (writer != null) {
                writer.close();
            }
        }

        return data;
    }

    private void persistData() {
        File dataFile = dataFile();

        try {
            Data data = new Data(id);
            JSONObject syncDataObject = toJSON(data);

            logger.debug("Persisting data " + data + " to " + dataFile.getAbsolutePath());

            Writer writer = new FileWriter(dataFile);
            try {
                syncDataObject.writeJSONString(writer);
            } finally {
                if (writer != null) {
                    writer.close();
                }
            }
        } catch (IOException e) {
            logger.warn("Unable to persist data to " + dataFile.getAbsolutePath());
        }
    }

    public void shutdown() {
        persistData();
    }

    @Override
    public String getId() {
        return id;
    }

    private static class Data {
        private String id;

        public Data(String id) {
            super();
            this.id = id;
        }

        public String getId() {
            return id;
        }
    }

    @Override
    public String getHostname() {
        return hostname;
    }

    @Override
    public int getPort() {
        return port;
    }
}