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.JexlExpression;
21 import org.apache.commons.jexl3.JexlContext;
22 import org.apache.commons.jexl3.JexlEngine;
23 import org.apache.commons.jexl3.MapContext;
24
25 import java.util.List;
26 import java.util.ArrayList;
27 import org.apache.commons.jexl3.JexlBuilder;
28 import org.junit.Test;
29
30 /**
31 * Simple example to show how to access arrays.
32 *
33 * @since 1.0
34 */
35 public class ArrayTest {
36 /**
37 * An example for array access.
38 */
39 static void example(final Output out) throws Exception {
40 /*
41 * First step is to retrieve an instance of a JexlEngine;
42 * it might be already existing and shared or created anew.
43 */
44 final JexlEngine jexl = new JexlBuilder().create();
45 /*
46 * Second make a jexlContext and put stuff in it
47 */
48 final JexlContext jc = new MapContext();
49
50 final List<Object> l = new ArrayList<>();
51 l.add("Hello from location 0");
52 final Integer two = 2;
53 l.add(two);
54 jc.set("array", l);
55
56 JexlExpression e = jexl.createExpression("array[1]");
57 Object o = e.evaluate(jc);
58 out.print("Object @ location 1 = ", o, two);
59
60 e = jexl.createExpression("array[0].length()");
61 o = e.evaluate(jc);
62
63 out.print("The length of the string at location 0 is : ", o, 21);
64 }
65
66 /**
67 * Unit test entry point.
68 * @throws Exception
69 */
70 @Test
71 public void testExample() throws Exception {
72 example(Output.JUNIT);
73 }
74
75 /**
76 * Command line entry point.
77 * @param args command line arguments
78 * @throws Exception cos jexl does.
79 */
80 public static void main(final String[] args) throws Exception {
81 example(Output.SYSTEM);
82 }
83 }