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Java > Open Source Codes > org > apache > commons > el > UnaryMinusOperator


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55
56 package org.apache.commons.el;
57
58 import javax.servlet.jsp.el.ELException JavaDoc;
59 import java.math.BigInteger JavaDoc;
60 import java.math.BigDecimal JavaDoc;
61
62 /**
63  *
64  * <p>The implementation of the unary minus operator
65  *
66  * @author Nathan Abramson - Art Technology Group
67  * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: luehe $
68  **/
69
70 public class UnaryMinusOperator
71   extends UnaryOperator
72 {
73   //-------------------------------------
74 // Singleton
75 //-------------------------------------
76
77   public static final UnaryMinusOperator SINGLETON =
78     new UnaryMinusOperator ();
79
80   //-------------------------------------
81 /**
82    *
83    * Constructor
84    **/
85   public UnaryMinusOperator ()
86   {
87   }
88
89   //-------------------------------------
90 // Expression methods
91 //-------------------------------------
92 /**
93    *
94    * Returns the symbol representing the operator
95    **/
96   public String JavaDoc getOperatorSymbol ()
97   {
98     return "-";
99   }
100
101   //-------------------------------------
102 /**
103    *
104    * Applies the operator to the given value
105    **/
106   public Object JavaDoc apply (Object JavaDoc pValue,
107                Logger pLogger)
108     throws ELException JavaDoc
109   {
110     if (pValue == null) {
111       /*
112       if (pLogger.isLoggingWarning ()) {
113     pLogger.logWarning
114       (Constants.ARITH_OP_NULL,
115        getOperatorSymbol ());
116       }
117       */
118       return PrimitiveObjects.getInteger (0);
119     }
120
121     else if (pValue instanceof BigInteger JavaDoc) {
122         return ((BigInteger JavaDoc) pValue).negate();
123     }
124
125     else if (pValue instanceof BigDecimal JavaDoc) {
126         return ((BigDecimal JavaDoc) pValue).negate();
127     }
128
129     else if (pValue instanceof String JavaDoc) {
130       if (Coercions.isFloatingPointString (pValue)) {
131     double dval =
132       ((Number JavaDoc)
133        (Coercions.coerceToPrimitiveNumber
134         (pValue, Double JavaDoc.class, pLogger))).
135       doubleValue ();
136     return PrimitiveObjects.getDouble (-dval);
137       }
138       else {
139     long lval =
140       ((Number JavaDoc)
141        (Coercions.coerceToPrimitiveNumber
142         (pValue, Long JavaDoc.class, pLogger))).
143       longValue ();
144     return PrimitiveObjects.getLong (-lval);
145       }
146     }
147
148     else if (pValue instanceof Byte JavaDoc) {
149       return PrimitiveObjects.getByte
150     ((byte) -(((Byte JavaDoc) pValue).byteValue ()));
151     }
152     else if (pValue instanceof Short JavaDoc) {
153       return PrimitiveObjects.getShort
154     ((short) -(((Short JavaDoc) pValue).shortValue ()));
155     }
156     else if (pValue instanceof Integer JavaDoc) {
157       return PrimitiveObjects.getInteger
158     ((int) -(((Integer JavaDoc) pValue).intValue ()));
159     }
160     else if (pValue instanceof Long JavaDoc) {
161       return PrimitiveObjects.getLong
162     ((long) -(((Long JavaDoc) pValue).longValue ()));
163     }
164     else if (pValue instanceof Float JavaDoc) {
165       return PrimitiveObjects.getFloat
166     ((float) -(((Float JavaDoc) pValue).floatValue ()));
167     }
168     else if (pValue instanceof Double JavaDoc) {
169       return PrimitiveObjects.getDouble
170     ((double) -(((Double JavaDoc) pValue).doubleValue ()));
171     }
172
173     else {
174       if (pLogger.isLoggingError ()) {
175     pLogger.logError
176       (Constants.UNARY_OP_BAD_TYPE,
177        getOperatorSymbol (),
178        pValue.getClass ().getName ());
179       }
180       return PrimitiveObjects.getInteger (0);
181     }
182   }
183
184   //-------------------------------------
185 }
186
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