com.heliosphere.athena.base.file.internal.resource.AbstractResource.java Source code

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Here is the source code for com.heliosphere.athena.base.file.internal.resource.AbstractResource.java

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/*
 * Copyright(c) 2016 - Heliosphere Corp.
 * ---------------------------------------------------------------------------
 * This file is part of the Heliosphere's project which is licensed under the 
 * Apache license version 2 and use is subject to license terms.
 * You should have received a copy of the license with the project's artifact
 * binaries and/or sources.
 * 
 * License can be consulted at http://www.apache.org/licenses/LICENSE-2.0
 * ---------------------------------------------------------------------------
 */
package com.heliosphere.athena.base.file.internal.resource;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;

import org.apache.commons.io.FilenameUtils;

import com.heliosphere.athena.base.resource.ResourceException;

/**
 * Provides an abstract implementation of a resource.
 * <hr>
 * @author <a href="mailto:christophe.resse@gmail.com">Resse Christophe - Heliosphere</a>
 * @version 1.0.0
 */
public abstract class AbstractResource implements IResource {
    /**
     * Default serialization identifier.
     */
    private static final long serialVersionUID = 1L;

    /**
     * Underlying file object.
     */
    private File file = null;

    /**
     * Creates a new abstract resource given a pathname.
     * <hr>
     * @param pathname Resource pathname.
     * @throws ResourceException Thrown in case an error occurred while trying to access the resource.
     */
    @SuppressWarnings("nls")
    public AbstractResource(String pathname) throws ResourceException {
        if (!loadAbsolute(pathname)) {
            if (!loadRelative(pathname)) {
                if (!loadRelativeSeparator(pathname)) {
                    throw new ResourceException(String
                            .format("The resource specified by the path name: %1s can not be found", pathname));
                }
            }
        }
    }

    @Override
    public File getFile() {
        return file;
    }

    /**
     * Loads the file considering its pathname is absolute.
     * <hr>
     * @param pathname Resource path name.
     * @return {@code True} if the resource can be loaded, {@code false} otherwise.
     */
    @SuppressWarnings("unused")
    private final boolean loadAbsolute(String pathname) {
        this.file = new File(pathname);
        if (!file.exists()) {
            try {
                file.createNewFile();
            } catch (IOException ioe) {
                return false;
            }
        }

        //String fullPath = file.getAbsolutePath();

        return this.file.exists();
    }

    /**
     * Loads the file considering its pathname is relative.
     * <hr>
     * @param pathname Resource path name.
     * @return {@code True} if the resource can be loaded, {@code false} otherwise.
     */
    @SuppressWarnings("unused")
    private final boolean loadRelative(String pathname) {
        URL url = null;

        try {
            // Maybe the file pathname is relative.
            url = Thread.currentThread().getContextClassLoader().getResource(pathname);

            this.file = new File(url.toURI());
            if (!file.exists()) {
                try {
                    file.createNewFile();
                } catch (IOException ioe) {
                    return false;
                }
            }
        } catch (Exception e) {
            // Try to get the parent directory of the file ... maybe the file does not exist!
            file = new File(pathname);
            String name = FilenameUtils.getName(pathname);
            File directory = file.getParentFile();
            try {
                url = Thread.currentThread().getContextClassLoader().getResource(file.getParent());

                try {
                    file = new File(url.toURI());
                    if (directory.exists() && directory.isDirectory()) {
                        // OK, found the parent directory, then create the file as it does not exist.
                        file = new File(directory.getAbsolutePath() + File.separator + name);
                        try {
                            file.createNewFile();
                        } catch (IOException e1) {
                            return false;
                        }
                    }
                } catch (URISyntaxException urie) {
                    return false;
                }
            } catch (Exception e2) {
                return false;
            }
        }

        return this.file.exists();
    }

    /**
     * Loads the file considering its pathname is relative.
     * <hr>
     * @param pathname Resource path name.
     * @return {@code True} if the resource can be loaded, {@code false} otherwise.
     */
    @SuppressWarnings({ "nls", "unused" })
    private final boolean loadRelativeSeparator(String pathname) {
        URL url = null;

        // Try to remove the leading file separator, if one exist.
        if (pathname.startsWith(File.separator)) {
            try {
                // Maybe the file pathname is relative.
                url = Thread.currentThread().getContextClassLoader()
                        .getResource(pathname.replaceFirst(File.separator, ""));
                this.file = new File(url.toURI());
                if (!file.exists()) {
                    try {
                        file.createNewFile();
                    } catch (IOException ioe) {
                        return false;
                    }
                }
            } catch (Exception e) {
                // Try to get the parent directory of the file ... maybe the file does not exist!
                file = new File(pathname);
                String name = FilenameUtils.getName(pathname);
                File directory = file.getParentFile();
                try {
                    url = Thread.currentThread().getContextClassLoader()
                            .getResource(file.getParent().replaceFirst(File.separator, ""));

                    try {
                        directory = new File(url.toURI());
                        if (directory.getAbsoluteFile().exists() && directory.getAbsoluteFile().isDirectory()) {
                            // OK, found the parent directory, then create the file as it does not exist.
                            file = new File(directory.getAbsolutePath() + File.separator + name);
                            try {
                                file.createNewFile();
                            } catch (IOException e1) {
                                return false;
                            }
                        }
                    } catch (URISyntaxException urie) {
                        return false;
                    }
                } catch (Exception e2) {
                    return false;
                }
            }
        }

        if (file == null) {
            return false;
        }

        return this.file.exists();
    }
}