librarysource.java

OSGI 的 源码实现,采用JAVA书写

/*
 * ModuleLoader - A generic, policy-driven class loader.
 * Copyright (c) 2004, Richard S. Hall
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of the ungoverned.org nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Contact: Richard S. Hall ([e-mail])
 * Contributor(s):
 *
**/
package org.ungoverned.moduleloader;

/**
 * <p>
 * This interface represents a source for obtaining native libraries for a
 * given module via the module's class loader. The main goal of a library
 * source is to map a library name to a path in the file system.
 * </p>
 * <p>
 * All library sources are initialized before first usage via a call
 * to the <a href="#open()"><tt>LibrarySource.open()</tt></a> method and
 * are also deinitialized via a call to
 * <a href="#open()"><tt>LibrarySource.close()</tt></a>. Library sources
 * should be implemented such that they can be opened, closed, and then
 * re-opened.
 * </p>
 * @see org.ungoverned.moduleloader.Module
 * @see org.ungoverned.moduleloader.ModuleClassLoader
**/
public interface LibrarySource
{
    /**
     * <p>
     * This method initializes the library source. It is called when
     * the associated module is added to the <tt>ModuleManager</tt>. It
     * is acceptable for implementations to ignore duplicate calls to this
     * method if the library source is already opened.
     * </p>
    **/
    public void open();

    /**
     * <p>
     * This method de-initializes the library source. It is called when
     * the associated module is removed from the <tt>ModuleManager</tt> or
     * when the module is reset by the <tt>ModuleManager</tt>.
     * </p>
    **/
    public void close();

    /**
     * <p>
     * Returns a file system path to the specified library.
     * </p>
     * @param name the name of the library that is being requested.
     * @return a file system path to the specified library.
     * @throws java.lang.IllegalStateException if the resource source has not
     *         been opened.
    **/
    public String getPath(String name) throws IllegalStateException;
}