1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.jexl3;
18
19 import org.apache.commons.jexl3.introspection.JexlPropertyGet;
20 import org.apache.commons.jexl3.introspection.JexlPropertySet;
21
22 /**
23 * Wraps an Object as a JEXL context and NamespaceResolver.
24 *
25 * @param <T> the wrapped object type to use
26 * @since 3.0
27 */
28 public class ObjectContext<T> implements JexlContext, JexlContext.NamespaceResolver {
29
30 /** The property solving jexl engine. */
31 private final JexlEngine jexl;
32
33 /** The object serving as context provider. */
34 private final T object;
35
36 /**
37 * Creates a new ObjectContext.
38 *
39 * @param engine the jexl engine to use to solve properties
40 * @param wrapped the object to wrap in this context
41 */
42 public ObjectContext(final JexlEngine engine, final T wrapped) {
43 this.jexl = engine;
44 this.object = wrapped;
45 }
46
47 @Override
48 public Object get(final String name) {
49 final JexlPropertyGet jget = jexl.getUberspect().getPropertyGet(object, name);
50 if (jget != null) {
51 try {
52 return jget.invoke(object);
53 } catch (final Exception xany) {
54 if (jexl.isStrict()) {
55 throw new JexlException.Property(null, name, true, xany);
56 }
57 }
58 }
59 return null;
60 }
61
62 /**
63 * @return the Jexl engine
64 */
65 protected JexlEngine getJexl() {
66 return jexl;
67 }
68
69 /**
70 * @return the object exposed by this context
71 */
72 protected T getObject() {
73 return object;
74 }
75
76 @Override
77 public boolean has(final String name) {
78 return jexl.getUberspect().getPropertyGet(object, name) != null;
79 }
80
81 @Override
82 public Object resolveNamespace(final String name) {
83 if (name == null || name.isEmpty()) {
84 return object;
85 }
86 return null;
87 }
88
89 @Override
90 public void set(final String name, final Object value) {
91 final JexlPropertySet jset = jexl.getUberspect().getPropertySet(object, name, value);
92 if (jset != null) {
93 try {
94 jset.invoke(object, value);
95 } catch (final Exception xany) {
96 // ignore
97 if (jexl.isStrict()) {
98 throw new JexlException.Property(null, name, true, xany);
99 }
100 }
101 }
102 }
103 }