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
18 package org.apache.commons.jexl3.examples;
19
20 import org.apache.commons.jexl3.JexlBuilder;
21 import org.apache.commons.jexl3.JexlExpression;
22 import org.apache.commons.jexl3.JexlContext;
23 import org.apache.commons.jexl3.JexlEngine;
24 import org.apache.commons.jexl3.MapContext;
25 import org.junit.Test;
26
27 /**
28 * Simple example to show how to access method and properties.
29 *
30 * @since 1.0
31 */
32 public class MethodPropertyTest {
33 /**
34 * An example for method access.
35 */
36 public static void example(final Output out) throws Exception {
37 /*
38 * First step is to retrieve an instance of a JexlEngine;
39 * it might be already existing and shared or created anew.
40 */
41 final JexlEngine jexl = new JexlBuilder().create();
42 /*
43 * Second make a jexlContext and put stuff in it
44 */
45 final JexlContext jc = new MapContext();
46
47 /*
48 * The Java equivalents of foo and number for comparison and checking
49 */
50 final Foo foo = new Foo();
51 final Integer number = 10;
52
53 jc.set("foo", foo);
54 jc.set("number", number);
55
56 /*
57 * access a method w/o args
58 */
59 JexlExpression e = jexl.createExpression("foo.getFoo()");
60 Object o = e.evaluate(jc);
61 out.print("value returned by the method getFoo() is : ", o, foo.getFoo());
62
63 /*
64 * access a method w/ args
65 */
66 e = jexl.createExpression("foo.convert(1)");
67 o = e.evaluate(jc);
68 out.print("value of " + e.getParsedText() + " is : ", o, foo.convert(1));
69
70 e = jexl.createExpression("foo.convert(1+7)");
71 o = e.evaluate(jc);
72 out.print("value of " + e.getParsedText() + " is : ", o, foo.convert(1+7));
73
74 e = jexl.createExpression("foo.convert(1+number)");
75 o = e.evaluate(jc);
76 out.print("value of " + e.getParsedText() + " is : ", o, foo.convert(1+ number));
77
78 /*
79 * access a property
80 */
81 e = jexl.createExpression("foo.bar");
82 o = e.evaluate(jc);
83 out.print("value returned for the property 'bar' is : ", o, foo.get("bar"));
84
85 }
86
87 /**
88 * Helper example class.
89 */
90 public static class Foo {
91 /**
92 * Gets foo.
93 * @return a string.
94 */
95 public String getFoo() {
96 return "This is from getFoo()";
97 }
98
99 /**
100 * Gets an arbitrary property.
101 * @param arg property name.
102 * @return arg prefixed with 'This is the property '.
103 */
104 public String get(final String arg) {
105 return "This is the property " + arg;
106 }
107
108 /**
109 * Gets a string from the argument.
110 * @param i a long.
111 * @return The argument prefixed with 'The value is : '
112 */
113 public String convert(final long i) {
114 return "The value is : " + i;
115 }
116 }
117
118
119 /**
120 * Unit test entry point.
121 * @throws Exception
122 */
123 @Test
124 public void testExample() throws Exception {
125 example(Output.JUNIT);
126 }
127
128 /**
129 * Command line entry point.
130 * @param args command line arguments
131 * @throws Exception cos jexl does.
132 */
133 public static void main(final String[] args) throws Exception {
134 example(Output.SYSTEM);
135 }
136 }