01: package org.drools.ruleflow.common.datatype.impl;
02:
03: /*
04: * Copyright 2005 JBoss Inc
05: *
06: * Licensed under the Apache License, Version 2.0 (the "License");
07: * you may not use this file except in compliance with the License.
08: * You may obtain a copy of the License at
09: *
10: * http://www.apache.org/licenses/LICENSE-2.0
11: *
12: * Unless required by applicable law or agreed to in writing, software
13: * distributed under the License is distributed on an "AS IS" BASIS,
14: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15: * See the License for the specific language governing permissions and
16: * limitations under the License.
17: */
18:
19: import org.drools.ruleflow.common.datatype.DataType;
20: import org.drools.ruleflow.common.datatype.DataTypeFactory;
21:
22: /**
23: * A data type factory that always returns the same instance of a given class.
24: *
25: * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>
26: */
27: public class InstanceDataTypeFactory implements DataTypeFactory {
28:
29: private Class dataTypeClass;
30: private DataType instance;
31:
32: public InstanceDataTypeFactory(final Class dataTypeClass) {
33: this .dataTypeClass = dataTypeClass;
34: }
35:
36: public DataType createDataType() {
37: if (this .instance == null) {
38: try {
39: this .instance = (DataType) this .dataTypeClass
40: .newInstance();
41: } catch (final IllegalAccessException e) {
42: throw new RuntimeException(
43: "Could not create data type for class "
44: + this .dataTypeClass, e);
45: } catch (final InstantiationException e) {
46: throw new RuntimeException(
47: "Could not create data type for class "
48: + this.dataTypeClass, e);
49: }
50: }
51: return this.instance;
52: }
53:
54: }
|