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Java > Open Source Codes > org > apache > cayenne > exp > parser > ASTNamedParameter


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19
20 package org.apache.cayenne.exp.parser;
21
22 import org.apache.cayenne.exp.Expression;
23 import org.apache.cayenne.exp.ExpressionException;
24 import org.apache.cayenne.exp.ExpressionParameter;
25
26 /**
27  * A named expression parameter.
28  *
29  * @since 1.1
30  * @author Andrus Adamchik
31  */
32 public class ASTNamedParameter extends ASTScalar {
33     ASTNamedParameter(int id) {
34         super(id);
35     }
36
37     public ASTNamedParameter() {
38         super(ExpressionParserTreeConstants.JJTNAMEDPARAMETER);
39     }
40
41     public ASTNamedParameter(Object JavaDoc value) {
42         super(ExpressionParserTreeConstants.JJTNAMEDPARAMETER);
43         setValue(value);
44     }
45
46     protected Object JavaDoc evaluateNode(Object JavaDoc o) throws Exception JavaDoc {
47         throw new ExpressionException(
48             "Uninitialized parameter: " + value + ", call 'expWithParameters' first.");
49     }
50
51     /**
52      * Creates a copy of this expression node, without copying children.
53      */
54     public Expression shallowCopy() {
55         ASTNamedParameter copy = new ASTNamedParameter(id);
56         copy.value = value;
57         return copy;
58     }
59
60     public void setValue(Object JavaDoc value) {
61         if (value == null) {
62             throw new ExpressionException("Null Parameter value");
63         }
64
65         String JavaDoc name = value.toString().trim();
66         if (name.length() == 0) {
67             throw new ExpressionException("Empty Parameter value");
68         }
69
70         super.setValue(new ExpressionParameter(name));
71     }
72 }
73
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