KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jexl > junit > Asserter


1 /*
2  * Copyright 2003-2006 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.commons.jexl.junit;
18
19 import java.util.HashMap JavaDoc;
20 import java.util.Map JavaDoc;
21
22 import junit.framework.Assert;
23
24 import org.apache.commons.jexl.Expression;
25 import org.apache.commons.jexl.ExpressionFactory;
26 import org.apache.commons.jexl.JexlContext;
27 import org.apache.commons.jexl.JexlHelper;
28
29 /**
30  * A utility class for performing JUnit based assertions using Jexl
31  * expressions. This class can make it easier to do unit tests using
32  * Jexl navigation expressions.
33  *
34  * @since 1.0
35  * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a>
36  * @version $Revision: 398153 $
37  */
38 public class Asserter extends Assert {
39
40     /** variables used during asserts. */
41     private final Map JavaDoc variables = new HashMap JavaDoc();
42     /** context to use during asserts. */
43     private final JexlContext context = JexlHelper.createContext();
44
45     /**
46      *
47      * Create an asserter.
48      */
49     public Asserter() {
50
51     }
52
53     /**
54      * This constructor will register the given variableValue as the
55      * "this" variable.
56      *
57      * @param variableValue 'this'.
58      */
59     public Asserter(Object JavaDoc variableValue) {
60         setVariable("this", variableValue);
61     }
62
63     /**
64      * Performs an assertion that the value of the given Jexl expression
65      * evaluates to the given expected value.
66      *
67      * @param expression is the Jexl expression to evaluate
68      * @param expected is the expected value of the expression
69      * @throws Exception if the expression could not be evaluationed or an assertion
70      * fails
71      */
72     public void assertExpression(String JavaDoc expression, Object JavaDoc expected) throws Exception JavaDoc {
73         Expression exp = ExpressionFactory.createExpression(expression);
74
75         context.setVars(variables);
76         Object JavaDoc value = exp.evaluate(context);
77
78         assertEquals("expression: " + expression, expected, value);
79     }
80
81     /**
82      * Puts a variable of a certain name in the context so that it can be used from
83      * assertion expressions.
84      *
85      * @param name variable name
86      * @param value variable value
87      */
88     public void setVariable(String JavaDoc name, Object JavaDoc value) {
89         variables.put(name, value);
90     }
91
92 }
93
Popular Tags