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1
28
29 package com.caucho.el;
30
31 import com.caucho.vfs.WriteStream;
32
33 import javax.el.ELContext;
34 import javax.el.ELException;
35 import java.io.IOException  ;
36 import java.util.Collection ;
37 import java.util.Map ;
38
39
42 public class UnaryExpr extends Expr {
43 private int _op;
44 private Expr _expr;
45
46
52 private UnaryExpr(int op, Expr expr)
53 {
54 _op = op;
55 _expr = expr;
56 }
57
58 public static Expr create(int op, Expr expr)
59 {
60 switch (op) {
61 case MINUS:
62 return new MinusExpr(expr);
63 }
64
65 return new UnaryExpr(op, expr);
66 }
67
68
71 @Override
72 public boolean isConstant()
73 {
74 return _expr.isConstant();
75 }
76
77
84 @Override
85 public Object getValue(ELContext env)
86 throws ELException
87 {
88 switch (_op) {
89 case NOT:
90 return new Boolean (! _expr.evalBoolean(env));
91
92 case MINUS:
93 {
94 Object obj = _expr.getValue(env);
95
96 if (obj == null)
97 return new Long (0);
98 else if (obj instanceof Double || obj instanceof Float )
99 return new Double (- ((Number ) obj).doubleValue());
100 else if (obj instanceof Number )
101 return new Long (- ((Number ) obj).longValue());
102 else if (obj instanceof String ) {
103 String s = (String ) obj;
104
105 if (s.indexOf('.') < 0)
106 return new Long (- toLong(obj, env));
107 else
108 return new Double (- toDouble(obj, env));
109 }
110 else
111 return new Double (- toDouble(obj, env));
112 }
113
114 case EMPTY:
115 if (evalBoolean(env))
116 return Boolean.TRUE;
117 else
118 return Boolean.FALSE;
119 }
120
121 throw new UnsupportedOperationException ();
122 }
123
124
131 @Override
132 public boolean evalBoolean(ELContext env)
133 throws ELException
134 {
135 switch (_op) {
136 case NOT:
137 return ! _expr.evalBoolean(env);
138
139 case EMPTY:
140 {
141 Object obj = _expr.getValue(env);
142
143 if (obj == null)
144 return true;
145 else if (obj instanceof String )
146 return "".equals(obj);
147 else if (obj instanceof Collection )
148 return ((Collection ) obj).isEmpty();
149 else if (obj instanceof Map )
150 return ((Map ) obj).isEmpty();
151 else if (obj.getClass().isArray())
152 return java.lang.reflect.Array.getLength(obj) == 0;
153 else
154 return false;
155 }
156 }
157
158 ELException e = new ELException(L.l("can't compare."));
159
160 error(e, env);
161
162 return false;
163 }
164
165
172 @Override
173 public long evalLong(ELContext env)
174 throws ELException
175 {
176 if (_op != MINUS) {
177 ELException e = new ELException(L.l("'not' and 'empty' operations can not be converted to long values."));
178 error(e, env);
179
180 return 0;
181 }
182
183 return - _expr.evalLong(env);
185 }
186
187
190 @Override
191 public double evalDouble(ELContext env)
192 throws ELException
193 {
194 if (_op != MINUS) {
195 ELException e = new ELException(L.l("'not' and 'empty' operations can not be converted to double values."));
196
197 error(e, env);
198
199 return 0;
200 }
201
202 return - _expr.evalDouble(env);
204 }
205
206
209 public void printCreate(WriteStream os)
210 throws IOException
211 {
212 os.print("com.caucho.el.UnaryExpr.create(");
213 os.print(_op + ", ");
214 _expr.printCreate(os);
215 os.print(")");
216 }
217
218
221 public boolean equals(Object o)
222 {
223 if (! (o instanceof UnaryExpr))
224 return false;
225
226 UnaryExpr uexpr = (UnaryExpr) o;
227
228 return (_op == uexpr._op && _expr.equals(uexpr._expr));
229 }
230
231
232
235 public String toString()
236 {
237 String op;
238
239 switch (_op) {
240 case MINUS:
241 op = " -";
242 break;
243 case NOT:
244 op = " not ";
245 break;
246 case EMPTY:
247 op = " empty ";
248 break;
249 default:
250 op = " unknown(" + _op + ") ";
251 break;
252 }
253
254 return op + _expr;
255 }
256 }
257 |
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