com.sun.enterprise.deployment.util.FileClassLoader Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.enterprise.deployment.util;

import com.sun.enterprise.util.LocalStringManagerImpl;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Hashtable;

public class FileClassLoader extends ClassLoader {

    String codebase;
    Hashtable cache = new Hashtable();

    private static LocalStringManagerImpl localStrings = new LocalStringManagerImpl(FileClassLoader.class);

    public FileClassLoader(String codebase) {
        this.codebase = codebase;
    }


    private byte[] loadClassData(String name) throws IOException {
        // load the class data from the codebase
        String sep = System.getProperty("file.separator");
        String c = name.replace('.', sep.charAt(0)) + ".class";
        File file = new File(codebase + sep + c);
        if (!file.exists()) {
            File wf = new File(codebase + sep + "WEB-INF" + sep + "classes" + sep + c);
            if (wf.exists()) {
                file = wf;
            }
        }
        FileInputStream fis = null;
        byte[] buf = null;
        try {
            fis = new FileInputStream(file);
            int avail = fis.available();
            buf = new byte[avail];
            fis.read(buf);
        } finally {
            if (fis != null) {
                fis.close();
            }
        }
        return buf;
    }


    String getClassName(File f) throws IOException, ClassFormatError {
        FileInputStream fis = null;
        byte[] buf = null;
        int avail = 0;
        try {
            fis = new FileInputStream(f);
            avail = fis.available();
            buf = new byte[avail];
            fis.read(buf);
        } finally {
            if (fis != null) {
                fis.close();
            }
        }
        Class c = super.defineClass(null, buf, 0, avail);
        return c.getName();
    }


    /**
     * @exception ClassNotFoundException if class load fails
     */
    @Override
    public synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
        Class c = (Class) cache.get(name);
        if (c == null) {
            try {
                byte data[] = loadClassData(name);
                c = defineClass(null, data, 0, data.length);
                if (!name.equals(c.getName())) {
                    throw new ClassNotFoundException(
                        localStrings.getLocalString("classloader.wrongpackage", "", new Object[] {name, c.getName()}));
                }
            } catch (Exception ex) {
                // Try to use default classloader. If this fails,
                // then a ClassNotFoundException is thrown.
                c = Class.forName(name);
            }
            cache.put(name, c);
        }
        if (resolve) {
            resolveClass(c);
        }
        return c;
    }


    @Override
    public String toString() {
        return "FileClassLoader: Codebase = " + codebase + "\n";
    }
}