1/**
2 * Copyright (C) 2008 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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
17package com.google.inject.internal;
18
19import com.google.inject.internal.BytecodeGen.Visibility;
20import com.google.inject.internal.InjectorImpl.MethodInvoker;
21import com.google.inject.spi.InjectionPoint;
22
23import java.lang.reflect.InvocationTargetException;
24import java.lang.reflect.Method;
25import java.lang.reflect.Modifier;
26
27/**
28 * Invokes an injectable method.
29 */
30final class SingleMethodInjector implements SingleMemberInjector {
31  private final MethodInvoker methodInvoker;
32  private final SingleParameterInjector<?>[] parameterInjectors;
33  private final InjectionPoint injectionPoint;
34
35  SingleMethodInjector(InjectorImpl injector, InjectionPoint injectionPoint, Errors errors)
36      throws ErrorsException {
37    this.injectionPoint = injectionPoint;
38    final Method method = (Method) injectionPoint.getMember();
39    methodInvoker = createMethodInvoker(method);
40    parameterInjectors = injector.getParametersInjectors(injectionPoint.getDependencies(), errors);
41  }
42
43  private MethodInvoker createMethodInvoker(final Method method) {
44
45    // We can't use FastMethod if the method is private.
46    int modifiers = method.getModifiers();
47    if (!Modifier.isPrivate(modifiers) && !Modifier.isProtected(modifiers)) {
48      /*if[AOP]*/
49      try {
50      final net.sf.cglib.reflect.FastMethod fastMethod
51          = BytecodeGen.newFastClass(method.getDeclaringClass(), Visibility.forMember(method))
52              .getMethod(method);
53
54      return new MethodInvoker() {
55        public Object invoke(Object target, Object... parameters)
56            throws IllegalAccessException, InvocationTargetException {
57          return fastMethod.invoke(target, parameters);
58        }
59      };
60      } catch (net.sf.cglib.core.CodeGenerationException e) {/* fall-through */}
61      /*end[AOP]*/
62    }
63
64    if (!Modifier.isPublic(modifiers) ||
65        !Modifier.isPublic(method.getDeclaringClass().getModifiers())) {
66      method.setAccessible(true);
67    }
68
69    return new MethodInvoker() {
70      public Object invoke(Object target, Object... parameters)
71          throws IllegalAccessException, InvocationTargetException {
72        return method.invoke(target, parameters);
73      }
74    };
75  }
76
77  public InjectionPoint getInjectionPoint() {
78    return injectionPoint;
79  }
80
81  public void inject(Errors errors, InternalContext context, Object o) {
82    Object[] parameters;
83    try {
84      parameters = SingleParameterInjector.getAll(errors, context, parameterInjectors);
85    } catch (ErrorsException e) {
86      errors.merge(e.getErrors());
87      return;
88    }
89
90    try {
91      methodInvoker.invoke(o, parameters);
92    } catch (IllegalAccessException e) {
93      throw new AssertionError(e); // a security manager is blocking us, we're hosed
94    } catch (InvocationTargetException userException) {
95      Throwable cause = userException.getCause() != null
96          ? userException.getCause()
97          : userException;
98      errors.withSource(injectionPoint).errorInjectingMethod(cause);
99    }
100  }
101}
102