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Java > Open Source Codes > org > apache > jasper > el > ExpressionEvaluatorImpl


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.jasper.el;
18
19 import javax.el.ELContext;
20 import javax.el.ExpressionFactory;
21 import javax.el.ValueExpression;
22 import javax.servlet.jsp.el.ELException JavaDoc;
23 import javax.servlet.jsp.el.ELParseException JavaDoc;
24 import javax.servlet.jsp.el.Expression JavaDoc;
25 import javax.servlet.jsp.el.ExpressionEvaluator JavaDoc;
26 import javax.servlet.jsp.el.FunctionMapper JavaDoc;
27 import javax.servlet.jsp.el.VariableResolver JavaDoc;
28
29
30 public final class ExpressionEvaluatorImpl extends ExpressionEvaluator JavaDoc {
31
32     private final ExpressionFactory factory;
33     
34     public ExpressionEvaluatorImpl(ExpressionFactory factory) {
35         this.factory = factory;
36     }
37
38     public Expression parseExpression(String JavaDoc expression, Class JavaDoc expectedType,
39             FunctionMapper JavaDoc fMapper) throws ELException JavaDoc {
40         try {
41             ELContextImpl ctx = new ELContextImpl(ELResolverImpl.DefaultResolver);
42             if (fMapper != null) {
43                 ctx.setFunctionMapper(new FunctionMapperImpl(fMapper));
44             }
45             ValueExpression ve = this.factory.createValueExpression(ctx, expression, expectedType);
46             return new ExpressionImpl(ve);
47         } catch (javax.el.ELException e) {
48             throw new ELParseException JavaDoc(e.getMessage());
49         }
50     }
51
52     public Object JavaDoc evaluate(String JavaDoc expression, Class JavaDoc expectedType,
53             VariableResolver JavaDoc vResolver, FunctionMapper JavaDoc fMapper)
54             throws ELException JavaDoc {
55         return this.parseExpression(expression, expectedType, fMapper).evaluate(vResolver);
56     }
57
58 }
59
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