com.github.cjwizard.FlatWizardSettings.java Source code

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Here is the source code for com.github.cjwizard.FlatWizardSettings.java

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/**
 * Copyright 2008 Eugene Creswick
 * 
 * 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.github.cjwizard;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.HashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * This settings can save pairs of key and values in a plain {@link HashMap}.
 * 
 * Note that this class doesn't implement the transaction model, and
 * so {@link #newPage(String)}, {@link #rollBack()} and {@link #commit()}
 * methods don't do anything.
 * 
 * @author ddearing
 */
public class FlatWizardSettings extends HashMap<String, Object> implements WizardSettings {
    /**
     * Serial version number, remember to change it when the class isn't binary
     * compatible with older versions.
     */
    private static final long serialVersionUID = 20141205L;

    /**
     * Commons logging log instance
     */
    private static Log log = LogFactory.getLog(FlatWizardSettings.class);

    /* (non-Javadoc)
     * @see com.github.cjwizard.WizardSettings#newPage(java.lang.String)
     */
    @Override
    public void newPage(String id) {
        // no-op
    }

    /* (non-Javadoc)
     * @see com.github.cjwizard.WizardSettings#rollBack()
     */
    @Override
    public void rollBack() {
        // no-op
    }

    /*
     * (non-Javadoc)
     * @see com.github.cjwizard.WizardSettings#commit()
     */
    @Override
    public void commit() {
        // no-op
    }

    /**
     * Serialize the current instance of {@link FlatWizardSettings} to the given
     * filename.
     * 
     * @param filename
     *           The filename.
     */
    public void serialize(String filename) {
        ObjectOutputStream out = null;
        FileOutputStream fout = null;
        try {
            fout = new FileOutputStream(filename);
            out = new ObjectOutputStream(fout);
            out.writeObject(this);
        } catch (IOException ioe) {
            log.error("Error writing settings", ioe);
        } finally {
            if (null != out) {
                try {
                    out.close();
                } catch (IOException ioe) {
                    log.error("Error closing output stream", ioe);
                }
            }
            if (null != fout) {
                try {
                    fout.close();
                } catch (IOException ioe) {
                    log.error("Error closing file", ioe);
                }
            }
        }
    }

    /**
     * Deserialize a {@link FlatWizardSettings} object from the specified file.
     * 
     * @param filename
     *           The filename.
     * @return The deserialized {@link FlatWizardSettings}.
     */
    static public FlatWizardSettings deserialize(String filename) {
        ObjectInputStream in = null;
        FileInputStream fin = null;
        try {
            fin = new FileInputStream(filename);
            in = new ObjectInputStream(fin);
            return (FlatWizardSettings) in.readObject();
        } catch (IOException ioe) {
            log.error("Error reading settings", ioe);
        } catch (ClassNotFoundException cnfe) {
            log.error("Couldn't instantiate seralized class", cnfe);
        } finally {
            if (null != in) {
                try {
                    in.close();
                } catch (IOException ioe) {
                    log.error("Error closing inputstream", ioe);
                }
            }
            if (null != fin) {
                try {
                    fin.close();
                } catch (IOException ioe) {
                    log.error("Error closing file", ioe);
                }
            }
        }
        return null;
    }

}