net.bytebuddy.dynamic.loading.ClassFilePostProcessor Maven / Gradle / Ivy
/*
* Copyright 2014 - Present Rafael Winterhalter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.bytebuddy.dynamic.loading;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.utility.nullability.AlwaysNull;
import net.bytebuddy.utility.nullability.MaybeNull;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.security.AllPermission;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.ProtectionDomain;
import java.util.Collections;
import java.util.Enumeration;
/**
* A post processor for class files.
*/
public interface ClassFilePostProcessor {
/**
* Transforms a class file for a given class.
*
* @param classLoader The class loader which is used to load a class or {@code null} if loaded by the bootstrap loader.
* @param name The binary name of the transformed class.
* @param protectionDomain The protection domain of the transformed class or {@code null} if no protection domain is provided.
* @param binaryRepresentation The binary representation of the class file.
* @return The class file to use.
*/
byte[] transform(@MaybeNull ClassLoader classLoader, String name, @MaybeNull ProtectionDomain protectionDomain, byte[] binaryRepresentation);
/**
* A non-operation class file post processor.
*/
enum NoOp implements ClassFilePostProcessor {
/**
* The singleton instance.
*/
INSTANCE;
/**
* {@inheritDoc}
*/
public byte[] transform(@MaybeNull ClassLoader classLoader, String name, @MaybeNull ProtectionDomain protectionDomain, byte[] binaryRepresentation) {
return binaryRepresentation;
}
}
/**
* A class file post processor that delegates to an {@link ClassFileTransformer}.
*/
@HashCodeAndEqualsPlugin.Enhance
class ForClassFileTransformer implements ClassFilePostProcessor {
/**
* A protection domain that represents all permissions.
*/
protected static final ProtectionDomain ALL_PRIVILEGES = new ProtectionDomain(null, new AllPermissionsCollection());
/**
* Indicates that a class is not currently loaded.
*/
@AlwaysNull
private static final Class UNLOADED_TYPE = null;
/**
* The class file transformer to delegate to.
*/
private final ClassFileTransformer classFileTransformer;
/**
* Creates a new class file post processor for a class file transformer.
*
* @param classFileTransformer The class file transformer to delegate to.
*/
public ForClassFileTransformer(ClassFileTransformer classFileTransformer) {
this.classFileTransformer = classFileTransformer;
}
/**
* {@inheritDoc}
*/
public byte[] transform(@MaybeNull ClassLoader classLoader, String name, @MaybeNull ProtectionDomain protectionDomain, byte[] binaryRepresentation) {
try {
byte[] transformed = classFileTransformer.transform(classLoader, name.replace('.', '/'),
UNLOADED_TYPE,
protectionDomain == null
? ALL_PRIVILEGES
: protectionDomain,
binaryRepresentation);
return transformed == null ? binaryRepresentation : transformed;
} catch (IllegalClassFormatException exception) {
throw new IllegalStateException("Failed to transform " + name, exception);
}
}
/**
* A permission collection that implies all permissions.
*/
@HashCodeAndEqualsPlugin.Enhance
protected static class AllPermissionsCollection extends PermissionCollection {
/**
* The serial version UID.
*/
private static final long serialVersionUID = 1L;
@Override
public void add(Permission permission) {
throw new UnsupportedOperationException("add");
}
@Override
public boolean implies(Permission permission) {
return true;
}
@Override
public Enumeration elements() {
return Collections.enumeration(Collections.singleton(new AllPermission()));
}
}
}
}