1 package org.apache.onami.lifecycle.core;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import com.google.inject.TypeLiteral;
23 import com.google.inject.spi.TypeEncounter;
24 import com.google.inject.spi.TypeListener;
25
26 import java.lang.annotation.Annotation;
27 import java.lang.reflect.Method;
28 import java.util.List;
29
30 /**
31 * A Guice {@code TypeListener} to hear annotated methods with lifecycle annotations.
32 */
33 abstract class AbstractMethodTypeListener
34 implements TypeListener
35 {
36
37 /**
38 * The {@code java} package constants.
39 */
40 private static final String JAVA_PACKAGE = "java";
41
42 /**
43 * The lifecycle annotations to search on methods in the order to be searched.
44 */
45 protected final List<? extends Class<? extends Annotation>> annotationTypes;
46
47 /**
48 * Creates a new methods listener instance.
49 *
50 * @param annotationTypes the lifecycle annotations to search on methods in the order to be searched.
51 */
52 public AbstractMethodTypeListener( List<? extends Class<? extends Annotation>> annotationTypes )
53 {
54 this.annotationTypes = annotationTypes;
55 }
56
57 /**
58 * {@inheritDoc}
59 */
60 @Override
61 public final <I> void hear( TypeLiteral<I> type, TypeEncounter<I> encounter )
62 {
63 hear( type, type.getRawType(), encounter );
64 }
65
66 /**
67 * Allows traverse the input klass hierarchy.
68 *
69 * @param parentType the owning type being heard
70 * @param klass encountered by Guice.
71 * @param encounter the injection context.
72 */
73 private <I> void hear( final TypeLiteral<I> parentType, Class<? super I> klass, TypeEncounter<I> encounter )
74 {
75 Package pkg;
76 if ( klass == null || ( ( pkg = klass.getPackage() ) != null && pkg.getName().startsWith( JAVA_PACKAGE ) ) )
77 {
78 return;
79 }
80
81 for ( Class<? extends Annotation> annotationType : annotationTypes )
82 {
83 for ( Method method : klass.getDeclaredMethods() )
84 {
85 if ( method.isAnnotationPresent( annotationType ) )
86 {
87 if ( method.getParameterTypes().length != 0 )
88 {
89 encounter.addError( "Annotated methods with @%s must not accept any argument, found %s",
90 annotationType.getName(), method );
91 }
92
93 hear( method, parentType, encounter, annotationType );
94 }
95 }
96 }
97
98 hear( parentType, klass.getSuperclass(), encounter );
99 }
100
101 /**
102 * Allows implementations to define the behavior when lifecycle annotation is found on the method.
103 *
104 * @param method encountered by this type handler.
105 * @param parentType the owning type being heard
106 * @param encounter the injection context.
107 * @param annotationType the annotation type that was specified.
108 */
109 protected abstract <I> void hear( Method method, TypeLiteral<I> parentType, TypeEncounter<I> encounter,
110 Class<? extends Annotation> annotationType );
111
112 }