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1
21 package com.db4o.nativequery.optimization;
22
23 import java.lang.reflect.*;
24
25 import com.db4o.nativequery.expr.cmp.*;
26 import com.db4o.nativequery.expr.cmp.field.*;
27
28 final class ComparisonQueryGeneratingVisitor implements ComparisonOperandVisitor {
29 private Object  _predicate;
30
31 private Object _value=null;
32
33 public Object value() {
34 return _value;
35 }
36
37 public void visit(ConstValue operand) {
38 _value = operand.value();
39 }
40
41 public void visit(FieldValue operand) {
42 operand.parent().accept(this);
43 Class clazz=((operand.parent() instanceof StaticFieldRoot) ? (Class )_value : _value.getClass());
44 try {
45 Field field=ReflectUtil.fieldFor(clazz,operand.fieldName());
46 _value=field.get(_value); } catch (Exception exc) {
48 exc.printStackTrace();
49 }
50 }
51
52 Object add(Object a,Object b) {
53 if(a instanceof Double ||b instanceof Double ) {
54 return new Double (((Double )a).doubleValue()+ ((Double )b).doubleValue());
55 }
56 if(a instanceof Float ||b instanceof Float ) {
57 return new Float (((Float )a).floatValue()+ ((Float )b).floatValue());
58 }
59 if(a instanceof Long ||b instanceof Long ) {
60 return new Long (((Long )a).longValue()+ ((Long )b).longValue());
61 }
62 return new Integer (((Integer )a).intValue()+ ((Integer )b).intValue());
63 }
64
65 Object subtract(Object a,Object b) {
66 if(a instanceof Double ||b instanceof Double ) {
67 return new Double (((Double )a).doubleValue()- ((Double )b).doubleValue());
68 }
69 if(a instanceof Float ||b instanceof Float ) {
70 return new Float (((Float )a).floatValue() - ((Float )b).floatValue());
71 }
72 if(a instanceof Long ||b instanceof Long ) {
73 return new Long (((Long )a).longValue() - ((Long )b).longValue());
74 }
75 return new Integer (((Integer )a).intValue() - ((Integer )b).intValue());
76 }
77
78 Object multiply(Object a,Object b) {
79 if(a instanceof Double ||b instanceof Double ) {
80 return new Double (((Double )a).doubleValue() * ((Double )b).doubleValue());
81 }
82 if(a instanceof Float ||b instanceof Float ) {
83 return new Float (((Float )a).floatValue() * ((Float )b).floatValue());
84 }
85 if(a instanceof Long ||b instanceof Long ) {
86 return new Long (((Long )a).longValue() * ((Long )b).longValue());
87 }
88 return new Integer (((Integer )a).intValue() * ((Integer )b).intValue());
89 }
90
91 Object divide(Object a,Object b) {
92 if(a instanceof Double ||b instanceof Double ) {
93 return new Double (((Double )a).doubleValue()/ ((Double )b).doubleValue());
94 }
95 if(a instanceof Float ||b instanceof Float ) {
96 return new Float (((Float )a).floatValue() / ((Float )b).floatValue());
97 }
98 if(a instanceof Long ||b instanceof Long ) {
99 return new Long (((Long )a).longValue() / ((Long )b).longValue());
100 }
101 return new Integer (((Integer )a).intValue() / ((Integer )b).intValue());
102 }
103
104 public void visit(ArithmeticExpression operand) {
105 operand.left().accept(this);
106 Object left=_value;
107 operand.right().accept(this);
108 Object right=_value;
109 switch(operand.op().id()) {
110 case ArithmeticOperator.ADD_ID:
111 _value=add(left,right);
112 break;
113 case ArithmeticOperator.SUBTRACT_ID:
114 _value=subtract(left,right);
115 break;
116 case ArithmeticOperator.MULTIPLY_ID:
117 _value=multiply(left,right);
118 break;
119 case ArithmeticOperator.DIVIDE_ID:
120 _value=divide(left,right);
121 break;
122 }
123 }
124
125 public void visit(CandidateFieldRoot root) {
126 }
127
128 public void visit(PredicateFieldRoot root) {
129 _value=_predicate;
130 }
131
132 public void visit(StaticFieldRoot root) {
133 try {
134 _value=Class.forName(root.className());
135 } catch (ClassNotFoundException e) {
136 e.printStackTrace();
137 }
138 }
139
140 public void visit(ArrayAccessValue operand) {
141 operand.parent().accept(this);
142 Object parent=_value;
143 operand.index().accept(this);
144 Integer index=(Integer )_value;
145 _value=Array.get(parent, index.intValue());
146 }
147
148 public void visit(MethodCallValue operand) {
149 operand.parent().accept(this);
150 Object receiver=_value;
151 Object [] params=new Object [operand.args().length];
152 for (int paramIdx = 0; paramIdx < operand.args().length; paramIdx++) {
153 operand.args()[paramIdx].accept(this);
154 params[paramIdx]=_value;
155 }
156 Class clazz=receiver.getClass();
157 if(operand.parent().root() instanceof StaticFieldRoot&&clazz.equals(Class .class)) {
158 clazz=(Class )receiver;
159 }
160 Method method=ReflectUtil.methodFor(clazz,operand.methodName(),operand.paramTypes());
161 try {
162 _value=method.invoke(receiver, params);
163 } catch (Exception exc) {
164 exc.printStackTrace();
165 _value=null;
166 }
167 }
168
169 public ComparisonQueryGeneratingVisitor(Object predicate) {
170 super();
171 this._predicate = predicate;
172 }
173
174 } |
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