001 package org.apache.commons.digester3.binder;
002
003 /*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements. See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership. The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License. You may obtain a copy of the License at
011 *
012 * http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied. See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022 import org.apache.commons.digester3.FactoryCreateRule;
023 import org.apache.commons.digester3.ObjectCreationFactory;
024
025 /**
026 * Builder chained when invoking {@link LinkedRuleBuilder#factoryCreate()}.
027 *
028 * @since 3.0
029 */
030 public final class FactoryCreateBuilder
031 extends AbstractBackToLinkedRuleBuilder<FactoryCreateRule>
032 {
033
034 private final ClassLoader classLoader;
035
036 private Class<? extends ObjectCreationFactory<?>> type;
037
038 private String attributeName;
039
040 private boolean ignoreCreateExceptions;
041
042 private ObjectCreationFactory<?> creationFactory;
043
044 FactoryCreateBuilder( String keyPattern, String namespaceURI, RulesBinder mainBinder,
045 LinkedRuleBuilder mainBuilder, ClassLoader classLoader )
046 {
047 super( keyPattern, namespaceURI, mainBinder, mainBuilder );
048 this.classLoader = classLoader;
049 }
050
051 /**
052 * Construct a factory create rule that will use the specified class name to create an {@link ObjectCreationFactory}
053 * which will then be used to create an object and push it on the stack.
054 *
055 * @param className Java class name of the object creation factory class
056 * @return this builder instance
057 */
058 @SuppressWarnings( "unchecked" ) // if class not assignable, will be notified via exception
059 public FactoryCreateBuilder ofType( String className )
060 {
061 if ( className == null )
062 {
063 reportError( "factoryCreate().ofType( String )", "NULL Java type not allowed" );
064 }
065
066 try
067 {
068 Class<?> type = this.classLoader.loadClass( className );
069 if ( !ObjectCreationFactory.class.isAssignableFrom( type ) )
070 {
071 reportError( "factoryCreate().ofType( String )", "NULL Java type not allowed" );
072 return this;
073 }
074
075 this.type = (Class<? extends ObjectCreationFactory<?>>) type;
076 }
077 catch ( ClassNotFoundException e )
078 {
079 reportError( "factoryCreate().ofType( String )", String.format( "class '%s' cannot be load", className ) );
080 }
081
082 return this;
083 }
084
085 /**
086 * Construct a factory create rule that will use the specified class to create an {@link ObjectCreationFactory}
087 * which will then be used to create an object and push it on the stack.
088 *
089 * @param type Java class of the object creation factory class
090 * @return this builder instance
091 */
092 public FactoryCreateBuilder ofType( Class<? extends ObjectCreationFactory<?>> type )
093 {
094 if ( type == null )
095 {
096 reportError( "factoryCreate().ofType( Class<? extends ObjectCreationFactory<?>> )",
097 "NULL Java type not allowed" );
098 }
099
100 this.type = type;
101
102 return this;
103 }
104
105 /**
106 * Construct a factory create rule using the given, already instantiated, {@link ObjectCreationFactory}.
107 *
108 * @param <T> the type of created object by the given factory
109 * @param creationFactory called on to create the object
110 * @return this builder instance
111 */
112 public <T> FactoryCreateBuilder usingFactory( /* @Nullable */ObjectCreationFactory<T> creationFactory )
113 {
114 this.creationFactory = creationFactory;
115 return this;
116 }
117
118 /**
119 * Allows specify the attribute containing an override class name if it is present.
120 *
121 * @param attributeName The attribute containing an override class name if it is present
122 * @return this builder instance
123 */
124 public FactoryCreateBuilder overriddenByAttribute( /* @Nullable */String attributeName )
125 {
126 this.attributeName = attributeName;
127 return this;
128 }
129
130 /**
131 * Exceptions thrown by the object creation factory will be ignored or not.
132 *
133 * @param ignoreCreateExceptions if true, exceptions thrown by the object creation factory will be ignored
134 * @return this builder instance
135 */
136 public FactoryCreateBuilder ignoreCreateExceptions( boolean ignoreCreateExceptions )
137 {
138 this.ignoreCreateExceptions = ignoreCreateExceptions;
139 return this;
140 }
141
142 /**
143 * {@inheritDoc}
144 */
145 @Override
146 protected FactoryCreateRule createRule()
147 {
148 if ( type == null && attributeName == null && creationFactory == null )
149 {
150 reportError( "factoryCreate()",
151 "at least one between 'className', 'attributeName' or 'creationFactory' has to be specified" );
152 }
153
154 if ( type != null || attributeName != null )
155 {
156 return new FactoryCreateRule( type, attributeName, ignoreCreateExceptions );
157 }
158
159 return new FactoryCreateRule( creationFactory, ignoreCreateExceptions );
160 }
161
162 }