net.java.dev.openim.tools.XStreamStore.java Source code

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Here is the source code for net.java.dev.openim.tools.XStreamStore.java

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/**
 * Copyright (c) 2008 Sonatype, Inc. All rights reserved.
 *
 * This program is licensed to you under the Apache License Version 2.0,
 * and you may not use this file except in compliance with the Apache License Version 2.0.
 * You may obtain a copy of the Apache License Version 2.0 at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the Apache License Version 2.0 is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
 */
package net.java.dev.openim.tools;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.codehaus.plexus.logging.Logger;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.DomDriver;

public class XStreamStore {
    public static final String DEFAULT_ENCODING = "UTF-8";

    private File file;
    private XStream xstream;
    private Logger logger;
    private Map map;

    private String substituteFrom;
    private String substituteTo;
    private String xmlProlog;

    public XStreamStore(File file, Logger logger) {
        this(file, logger, DEFAULT_ENCODING);
    }

    public XStreamStore(File file, Logger logger, String encoding) {
        this.file = file;
        this.logger = logger;
        xstream = new XStream(new DomDriver());
        String enc = encoding != null ? encoding : DEFAULT_ENCODING;
        xmlProlog = "<?xml version='1.0' encoding='" + enc + "'?>";
    }

    public void load() {
        map = loadMap();
    }

    //  --------------------------------------------------------------------------    
    public void alias(String name, Class classz) {
        xstream.alias(name, classz);
    }

    //  --------------------------------------------------------------------------    
    public void substitute(String from, String to) {
        substituteFrom = from;
        substituteTo = to;
    }

    //  --------------------------------------------------------------------------
    public Object get(Object key) {
        Object value = null;
        synchronized (map) {
            value = map.get(key);
        }
        return value;
    }

    //  --------------------------------------------------------------------------
    public Object remove(Object key) {
        Object value = null;
        synchronized (map) {
            value = map.remove(key);
            saveMap(map);
        }
        return value;
    }

    //  --------------------------------------------------------------------------
    @SuppressWarnings("unchecked")
    public void put(Object key, Object value) {
        synchronized (map) {
            value = map.put(key, value);
            saveMap(map);
        }
    }

    //  --------------------------------------------------------------------------    
    private Logger getLogger() {
        return logger;
    }

    //--------------------------------------------------------------------------
    //--------------------------------------------------------------------------
    //--------------------------------------------------------------------------
    //--------------------------------------------------------------------------
    private void saveMap(Map map) {
        String xstreamData = xstream.toXML(map);
        if (substituteFrom != null && substituteTo != null) {
            xstreamData = StringUtils.replace(xstreamData, substituteFrom, substituteTo);
        }
        xstreamData = xmlProlog + "\n" + xstreamData;
        //getLogger().info("saving roster " + xstreamData);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            fos.write(xstreamData.getBytes());
        } catch (IOException e) {
            getLogger().error(e.getMessage(), e);
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    getLogger().error(e.getMessage());
                }
            }
        }

    }

    //--------------------------------------------------------------------------
    private Map loadMap() {
        Map map = null;

        if (file.exists()) {
            try {
                FileInputStream fis = new FileInputStream(file);
                String xmlData = IOUtils.toString(fis);
                fis.close();
                if (substituteFrom != null && substituteTo != null) {
                    xmlData = StringUtils.replace(xmlData, substituteTo, substituteFrom);
                }
                map = (Map) xstream.fromXML(xmlData);
            } catch (Exception e) {
                getLogger().error(e.getMessage(), e);
            }

        } else {
            getLogger().info("No " + file + " => starting with void store");
            map = new HashMap();
        }

        return map;
    }

}