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


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19
20 package org.apache.cayenne.exp.parser;
21
22 import org.apache.cayenne.exp.Expression;
23 import org.apache.commons.collections.Transformer;
24
25 /**
26  * "In" expression.
27  *
28  * @author Andrus Adamchik
29  */
30 public class ASTIn extends ConditionNode {
31
32     /**
33      * Constructor used by expression parser. Do not invoke directly.
34      */
35     ASTIn(int id) {
36         super(id);
37     }
38
39     public ASTIn() {
40         super(ExpressionParserTreeConstants.JJTIN);
41     }
42
43     public ASTIn(ASTPath path, ASTList list) {
44         super(ExpressionParserTreeConstants.JJTIN);
45         jjtAddChild(path, 0);
46         jjtAddChild(list, 1);
47     }
48
49     protected Object JavaDoc evaluateNode(Object JavaDoc o) throws Exception JavaDoc {
50         int len = jjtGetNumChildren();
51         if (len != 2) {
52             return Boolean.FALSE;
53         }
54
55         Object JavaDoc o1 = evaluateChild(0, o);
56         if (o1 == null) {
57             return Boolean.FALSE;
58         }
59
60         Object JavaDoc[] objects = (Object JavaDoc[]) evaluateChild(1, o);
61         if (objects == null) {
62             return Boolean.FALSE;
63         }
64
65         int size = objects.length;
66         for (int i = 0; i < size; i++) {
67             if (o1.equals(objects[i])) {
68                 return Boolean.TRUE;
69             }
70         }
71
72         return Boolean.FALSE;
73     }
74
75     /**
76      * Creates a copy of this expression node, without copying children.
77      */
78     public Expression shallowCopy() {
79         return new ASTIn(id);
80     }
81
82     protected String JavaDoc getExpressionOperator(int index) {
83         return "in";
84     }
85
86     public int getType() {
87         return Expression.IN;
88     }
89
90     protected Object JavaDoc transformExpression(Transformer transformer) {
91         Object JavaDoc transformed = super.transformExpression(transformer);
92         
93         // transform empty ASTIn to ASTFalse
94 if (transformed instanceof ASTIn) {
95             ASTIn exp = (ASTIn) transformed;
96             if (exp.jjtGetNumChildren() == 2) {
97                 ASTList list = (ASTList) exp.jjtGetChild(1);
98                 Object JavaDoc[] objects = (Object JavaDoc[]) list.evaluate(null);
99                 if (objects.length == 0) {
100                     transformed = new ASTFalse();
101                 }
102             }
103         }
104
105         return transformed;
106     }
107
108 }
109
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