com.alta189.deskbin.util.KeyStore.java Source code

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Here is the source code for com.alta189.deskbin.util.KeyStore.java

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/*
 * This file is part of DeskBin.
 *
 * Copyright (c) 2012, alta189 <http://github.com/alta189/DeskBin/>
 * DeskBin is licensed under the GNU Lesser General Public License.
 *
 * DeskBin is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * DeskBin is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.alta189.deskbin.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.concurrent.ConcurrentHashMap;

import com.alta189.commons.util.CastUtil;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.SerializationUtils;
import org.yaml.snakeyaml.external.biz.base64Coder.Base64Coder;

public class KeyStore {
    private static final KeyStore instance;
    private final ConcurrentHashMap<String, String> map = new ConcurrentHashMap<String, String>();
    private final File saveFile = new File(PlatformUtils.getWorkingDirectory(),
            "data" + File.separator + "store.ser");
    private final Object key = new Object();

    static {
        instance = new KeyStore();

        // Ensure CryptUtils key is loaded
        CryptUtils.getSecretKey();

        // Load
        load();

        // Add shutdown hook to save the store
        Runtime.getRuntime().addShutdownHook(new Thread(new SafeSaveRunnable()));
    }

    public static void store(String key, Object o) {
        if (key == null || key.isEmpty()) {
            throw new IllegalAccessError();
        }
        instance.storeImpl(key, o);
    }

    public static <T> T get(String key) {
        if (key == null || key.isEmpty()) {
            throw new IllegalAccessError();
        }
        return instance.getImpl(key);
    }

    public static boolean contains(String key) {
        return !(key == null || key.isEmpty()) && instance.map.containsKey(key);
    }

    public static void remove(String key) {
        if (key != null && !key.isEmpty()) {
            instance.map.remove(key);
        }
    }

    public static void load() {
        ConcurrentHashMap<String, String> loadedMap = instance.loadImpl();
        instance.map.clear();
        instance.map.putAll(loadedMap);
    }

    public static void save() {
        instance.saveImpl();
    }

    private void storeImpl(String key, Object o) {
        if (o == null) {
            o = new NullObject();
        }
        String data = toString(CastUtil.safeCast(o, Serializable.class));
        String encryptedData = CryptUtils.encrypt(data);
        map.put(key, encryptedData);
    }

    private <T> T getImpl(String key) {
        String data = map.get(key);
        if (data == null || data.isEmpty()) {
            return null;
        }
        String decryptedData = CryptUtils.decrypt(data);
        Object o = fromString(decryptedData);
        if (o instanceof NullObject) {
            return null;
        }
        return CastUtil.safeCast(o);
    }

    private ConcurrentHashMap<String, String> loadImpl() {
        synchronized (key) {
            String data = null;

            if (saveFile.exists()) {
                try {
                    data = FileUtils.readFileToString(saveFile);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (data == null || data.isEmpty()) {
                return new ConcurrentHashMap<String, String>();
            } else {
                return CastUtil.safeCast(fromString(data));
            }
        }
    }

    private void saveImpl() {
        synchronized (key) {
            if (!map.isEmpty()) {
                String data = toString(map);
                try {
                    FileUtils.write(saveFile, data);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                saveFile.delete();
            }
        }
    }

    private Object fromString(String s) {
        ObjectInputStream ois = null;
        try {
            byte[] data = Base64Coder.decode(s);
            ois = new ObjectInputStream(new ByteArrayInputStream(data));
            return SerializationUtils.deserialize(ois);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IOUtils.closeQuietly(ois);
        }
        return null;
    }

    private String toString(Serializable o) {
        ByteArrayOutputStream baos = null;
        ObjectOutputStream oos = null;
        try {
            baos = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(baos);
            SerializationUtils.serialize(o, oos);
            return new String(Base64Coder.encode(baos.toByteArray()));
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IOUtils.closeQuietly(oos);
            IOUtils.closeQuietly(baos);
        }
        return null;
    }

    static class NullObject implements Serializable {
        private static final long serialVersionUID = 6437740969004810019L;
    }

    static class SafeSaveRunnable implements Runnable {
        @Override
        public void run() {
            save();
        }
    }
}