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/*
* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package nsk.share;
import java.io.*;
/**
* The <code>CustomClassLoader</code> class is used in <code>ClassUnloader</code>.
*
* <p>This class loader can load classes and notify <code>ClassUnloader</code>
* about own finalization to make sure that all loaded classes have been unloaded.
*
* <p>By default this class loader loads class from .class file located in directory
* specified with <code>setClassPath()</code> method. To use any other technique
* of class loading one should implement derived class, which would override
* <code>findClass</code> method.
*
* @see nsk.share.ClassUnloader
*
* @see #setClassPath(String)
* @see #findClass(String)
*/
public class CustomClassLoader extends ClassLoader {
private ClassUnloader classUnloader;
protected String classPath;
/**
* Initializes a newly created <code>CustomClassloader</code> object
* not yet linked with any <code>ClassUnloader</code> object.
*
*/
public CustomClassLoader() {
super(CustomClassLoader.class.getClassLoader());
this.classUnloader = null;
}
/**
* Initializes a newly created <code>CustomClassloader</code> object
* linked with specified <code>ClassUnloader</code> object.
*
* @param classUnloader an instance of <code>ClassUnloader</code>
*/
public CustomClassLoader(ClassUnloader classUnloader) {
super(CustomClassLoader.class.getClassLoader());
this.classUnloader = classUnloader;
}
/**
* Links this class loader with specified <code>ClassUnloader</code> object.
*
* @param classUnloader an instance of <code>ClassUnloader</code>
*/
public void setClassUnloader(ClassUnloader classUnloader) {
this.classUnloader = classUnloader;
}
/**
* Specifies path to .class file location.
*
* @param classPath a path to .class file location
*/
public void setClassPath(String classPath) {
this.classPath = classPath;
}
/**
* Finds and loads class for specified class name.
* This method loads class from .class file located in a directory
* previously specified by <code>setClassPath()</code>.
*
* @param name The name of the class.
*
* @throws ClassNotFoundException if no .class file found
* for specified class name
*
* @see #setClassPath(String)
*/
protected synchronized Class findClass(String name) throws ClassNotFoundException {
java.nio.file.Path path = ClassFileFinder.findClassFile(name, classPath);
if (path == null) {
throw new ClassNotFoundException(name);
}
String classFileName = path.toString();
FileInputStream in;
try {
in = new FileInputStream(classFileName);
if (in == null) {
throw new ClassNotFoundException(classFileName);
}
} catch (FileNotFoundException e) {
throw new ClassNotFoundException(classFileName, e);
}
int len;
byte data[];
try {
len = in.available();
data = new byte[len];
for (int total = 0; total < data.length; ) {
total += in.read(data, total, data.length - total);
}
} catch (IOException e) {
throw new ClassNotFoundException(classFileName, e);
} finally {
try {
in.close();
} catch (IOException e) {
throw new ClassNotFoundException(classFileName, e);
}
}
return defineClass(name, data, 0, data.length);
}
/**
* Notifies <code>ClassUnloader</code> about finalization.
*/
protected void finalize() throws Throwable {
// notify ClassUnloader about finalization
if (classUnloader != null) {
classUnloader.finalized = true;
}
super.finalize();
}
}
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