01: /*
02: * Copyright 2002-2006 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.springframework.instrument.classloading;
18:
19: import java.lang.instrument.ClassFileTransformer;
20:
21: /**
22: * Defines the contract for adding one or more
23: * {@link ClassFileTransformer ClassFileTransformers} to a
24: * {@link ClassLoader} - typically the current context class loader.
25: *
26: * <p>Implementations may of course provide their own class loader as well.
27: *
28: * @author Rod Johnson
29: * @author Costin Leau
30: * @since 2.0
31: */
32: public interface LoadTimeWeaver {
33:
34: /**
35: * Add a class file transformer to be applied by this load-time weaver.
36: * @param transformer the class file transformer to add
37: */
38: void addTransformer(ClassFileTransformer transformer);
39:
40: /**
41: * Return a class loader that supports instrumentation through AspectJ-style load-time
42: * weaving based on user-defined {@link ClassFileTransformer ClassFileTransformers}.
43: * <p>May be the current class loader, or a class loader created by this
44: * {@link LoadTimeWeaver} instance.
45: * @return a class loader that supports instrumentation through AspectJ-style load-time
46: * weaving based on user-defined {@link ClassFileTransformer ClassFileTransformers}
47: */
48: ClassLoader getInstrumentableClassLoader();
49:
50: /**
51: * Return a throwaway class loader, enabling classes to be loaded and
52: * inspected without affecting the parent class loader.
53: * <p>Should <i>not</i> return the same instance of the {@link ClassLoader}
54: * returned from an invocation of {@link #getInstrumentableClassLoader()}.
55: * @return a temporary throwaway class loader; should return a new
56: * instance for each call, with no existing state
57: */
58: ClassLoader getThrowawayClassLoader();
59:
60: }
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