bcv-vf/src/org/codehaus/janino/util/ResourceFinderClassLoader.java

108 lines
4.3 KiB
Java

/*
* Janino - An embedded Java[TM] compiler
*
* Copyright (c) 2001-2010, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
package org.codehaus.janino.util;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.codehaus.janino.JaninoRuntimeException;
import org.codehaus.janino.util.resource.Resource;
import org.codehaus.janino.util.resource.ResourceFinder;
/**
* A {@link ClassLoader} that uses a {@link org.codehaus.janino.util.resource.ResourceFinder} to find ".class" files.
*/
@SuppressWarnings({ "rawtypes", "unchecked" }) public
class ResourceFinderClassLoader extends ClassLoader {
private final ResourceFinder resourceFinder;
public
ResourceFinderClassLoader(ResourceFinder resourceFinder, ClassLoader parent) {
super(parent);
this.resourceFinder = resourceFinder;
}
/** @return The underlying {@link ResourceFinder} */
public ResourceFinder
getResourceFinder() { return this.resourceFinder; }
@Override protected Class
findClass(String className) throws ClassNotFoundException {
// Find the resource containing the class bytecode.
Resource classFileResource = this.resourceFinder.findResource(ClassFile.getClassFileResourceName(className));
if (classFileResource == null) throw new ClassNotFoundException(className);
// Open the class file resource.
InputStream is;
try {
is = classFileResource.open();
} catch (IOException ex) {
throw new JaninoRuntimeException((
"Opening class file resource \""
+ classFileResource.getFileName()
+ "\": "
+ ex.getMessage()
), ex);
}
// Read bytecode from the resource into a byte array.
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
byte[] buffer = new byte[4096];
for (;;) {
int bytesRead = is.read(buffer);
if (bytesRead == -1) break;
baos.write(buffer, 0, bytesRead);
}
} catch (IOException ex) {
throw new ClassNotFoundException("Reading class file from \"" + classFileResource + "\"", ex);
} finally {
try { is.close(); } catch (IOException ex) {}
}
byte[] ba = baos.toByteArray();
// Define the class in this ClassLoader.
Class clazz = super.defineClass(null, ba, 0, ba.length);
if (!clazz.getName().equals(className)) {
// This is a really complicated case: We may find a class file on
// the class path that seemingly defines the class we are looking
// for, but doesn't. This is possible if the underlying file system
// has case-insensitive file names and/or file names that are
// limited in length (e.g. DOS 8.3).
throw new ClassNotFoundException(className);
}
return clazz;
}
}