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Java > Open Source Codes > org > objectweb > medor > expression > lib > Concat


1 /**
2  * MEDOR: Middleware Enabling Distributed Object Requests
3  *
4  * Copyright (C) 2001-2003 France Telecom R&D
5  * Contact: alexandre.lefebvre@rd.francetelecom.com
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  *
21  * Initial developers: M. Alia, A. Lefebvre
22  */
23
24 package org.objectweb.medor.expression.lib;
25
26 import org.objectweb.jorm.type.api.PType;
27 import org.objectweb.jorm.type.api.PTypeSpace;
28 import org.objectweb.medor.expression.api.BinaryOperator;
29 import org.objectweb.medor.expression.api.Expression;
30 import org.objectweb.medor.expression.api.ExpressionException;
31 import org.objectweb.medor.expression.api.MalformedExpressionException;
32 import org.objectweb.medor.expression.api.Operand;
33 import org.objectweb.medor.expression.api.Operator;
34 import org.objectweb.medor.expression.api.ParameterOperand;
35 import org.objectweb.medor.expression.api.TypingException;
36
37 public class Concat extends BasicBinaryOperator implements BinaryOperator {
38
39     /**
40      * Returns the concatenation of two strings.
41      * @param e0 the first Expression to be concatenated
42      * @param e1 the second Expression to be concatenated
43      */
44     public Concat(Expression e0, Expression e1) {
45         super(PTypeSpace.STRING, e0, e1);
46     }
47
48     public Concat() {
49         super(PTypeSpace.STRING);
50     }
51
52     public org.objectweb.medor.expression.api.Operand evaluate(ParameterOperand[] pos, Object JavaDoc o)
53         throws ExpressionException {
54         try {
55             result.setValue(
56                     evaluate(
57                             expressions[0].evaluate(pos, o).getString(),
58                             expressions[1].evaluate(pos, o).getString()));
59         }
60         catch (NullPointerException JavaDoc e) {
61             // result == null or missing children objects
62 throw new IllegalStateException JavaDoc("Unevaluable Expression: Not compiled");
63         }
64         return result;
65     }
66
67     public String JavaDoc evaluate(String JavaDoc op1, String JavaDoc op2) {
68         return op1.concat(op2);
69     }
70
71     public Operand compileExpression()
72         throws ExpressionException, MalformedExpressionException {
73         if ((expressions[0] != null) && (expressions[1] != null)) {
74             expressions[0].compileExpression();
75             expressions[1].compileExpression();
76             if (!(expressions[0].getType() == null || expressions[1].getType() == null)) {
77                 if ((expressions[0].getType().getTypeCode() == PType.TYPECODE_STRING) &&
78                     (expressions[1].getType().getTypeCode() == PType.TYPECODE_STRING)) {
79                     type = PTypeSpace.STRING;
80                     result = new BasicVariableOperand(type);
81                     verified = true;
82                 }
83                 else
84                 // it is not a string type
85 throw new TypingException("Attempt arg type : String, String");
86             }
87             else
88                 throw new MalformedExpressionException("null children value");
89         }
90         else
91         // Operands not yet assigned
92 throw new MalformedExpressionException("null children value");
93         return result;
94     }
95
96     public String JavaDoc getOperatorString() {
97         return Operator.CONCAT;
98     }
99 }
100
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