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/*
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * glassfish/bootstrap/legal/CDDLv1.0.txt or
 * https://glassfish.dev.java.net/public/CDDLv1.0.html.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * HEADER in each file and include the License file at
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable,
 * add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your
 * own identifying information: Portions Copyright [yyyy]
 * [name of copyright owner]
 *
 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
 *
 * Portions Copyright Apache Software Foundation.
 */ 

package org.apache.taglibs.standard.lang.jstl;

import java.beans.PropertyEditor;
import java.beans.PropertyEditorManager;

/**
 *
 * 

This class contains the logic for coercing data types before * operators are applied to them. * *

The following is the list of rules applied for various type * conversions. * *

     * Applying arithmetic operator
     *   Binary operator - A {+,-,*} B
     *     if A and B are null
     *       return 0
     *     if A or B is Float, Double, or String containing ".", "e", or "E"
     *       coerce both A and B to Double
     *       apply operator
     *     otherwise
     *       coerce both A and B to Long
     *       apply operator
     *     if operator results in exception (such as divide by 0), error
     * 
     *   Binary operator - A {/,div} B
     *     if A and B are null
     *       return 0
     *     otherwise
     *       coerce both A and B to Double
     *       apply operator
     *     if operator results in exception (such as divide by 0), error
     * 
     *   Binary operator - A {%,mod} B
     *     if A and B are null
     *       return 0
     *     if A or B is Float, Double, or String containing ".", "e" or "E"
     *       coerce both to Double
     *       apply operator
     *     otherwise
     *       coerce both A and B to Long
     *       apply operator
     *     if operator results in exception (such as divide by 0), error
     * 
     *   Unary minus operator - -A
     *     if A is null
     *       return 0
     *     if A is String
     *       if A contains ".", "e", or "E"
     *         coerce to Double, apply operator
     *       otherwise
     *         coerce to a Long and apply operator
     *     if A is Byte,Short,Integer,Long,Float,Double
     *       retain type, apply operator
     *     if operator results in exception, error
     *     otherwise
     *       error
     *
     * Applying "empty" operator - empty A
     *   if A is null
     *     return true
     *   if A is zero-length String
     *     return true
     *   if A is zero-length array
     *     return true
     *   if A is List and ((List) A).isEmpty()
     *     return true
     *   if A is Map and ((Map) A).isEmpty()
     *     return true
     *   otherwise
     *     return false
     * 
     * Applying logical operators
     *   Binary operator - A {and,or} B
     *     coerce both A and B to Boolean, apply operator
     *   NOTE - operator stops as soon as expression can be determined, i.e.,
     *     A and B and C and D - if B is false, then only A and B is evaluated
     *   Unary not operator - not A
     *     coerce A to Boolean, apply operator
     * 
     * Applying relational operator
     *   A {<,>,<=,>=,lt,gt,lte,gte} B
     *     if A==B
     *       if operator is >= or <=
     *         return true
     *       otherwise
     *         return false
     *     if A or B is null
     *       return false
     *     if A or B is Float or Double
     *       coerce both A and B to Double
     *       apply operator
     *     if A or B is Byte,Short,Character,Integer,Long
     *       coerce both A and B to Long
     *       apply operator
     *     if A or B is String
     *       coerce both A and B to String, compare lexically
     *     if A is Comparable
     *       if A.compareTo (B) throws exception
     *         error
     *       otherwise
     *         use result of A.compareTo(B)
     *     if B is Comparable
     *       if B.compareTo (A) throws exception
     *         error
     *       otherwise
     *         use result of B.compareTo(A)
     *     otherwise
     *       error
     * 
     * Applying equality operator
     *   A {==,!=} B
     *     if A==B
     *       apply operator
     *     if A or B is null
     *       return false for ==, true for !=
     *     if A or B is Float or Double
     *       coerce both A and B to Double
     *       apply operator
     *     if A or B is Byte,Short,Character,Integer,Long
     *       coerce both A and B to Long
     *       apply operator
     *     if A or B is Boolean
     *       coerce both A and B to Boolean
     *       apply operator
     *     if A or B is String
     *       coerce both A and B to String, compare lexically
     *     otherwise
     *       if an error occurs while calling A.equals(B)
     *         error
     *       apply operator to result of A.equals(B)
     * 
     * coercions
     * 
     *   coerce A to String
     *     A is String
     *       return A
     *     A is null
     *       return ""
     *     A.toString throws exception
     *       error
     *     otherwise
     *       return A.toString
     * 
     *   coerce A to primitive Number type N
     *     A is null or ""
     *       return 0
     *     A is Character
     *       convert to short, apply following rules
     *     A is Boolean
     *       error
     *     A is Number type N
     *       return A
     *     A is Number with less precision than N
     *       coerce quietly
     *     A is Number with greater precision than N
     *       coerce quietly
     *     A is String
     *       new N.valueOf(A) throws exception
     *         error
     *       return N.valueOf(A)
     *     otherwise
     *       error
     * 
     *   coerce A to Character should be
     *     A is null or ""
     *       return (char) 0
     *     A is Character
     *       return A
     *     A is Boolean
     *       error
     *     A is Number with less precision than short
     *       coerce quietly - return (char) A
     *     A is Number with greater precision than short
     *       coerce quietly - return (char) A
     *     A is String
     *       return A.charAt (0)
     *     otherwise
     *       error
     * 
     *   coerce A to Boolean
     *     A is null or ""
     *       return false
     *     A is Boolean
     *       return A
     *     A is String
     *       Boolean.valueOf(A) throws exception
     *         error
     *       return Boolean.valueOf(A)
     *     otherwise
     *       error
     * 
     *   coerce A to any other type T
     *     A is null
     *       return null
     *     A is assignable to T
     *       coerce quietly
     *     A is String
     *       T has no PropertyEditor
     *         if A is "", return null
     *         otherwise error
     *       T's PropertyEditor throws exception
     *         if A is "", return null
     *         otherwise error
     *       otherwise
     *         apply T's PropertyEditor
     *     otherwise
     *       error
     * 
* * @author Nathan Abramson - Art Technology Group * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $ **/ public class Coercions { //------------------------------------- /** * * Coerces the given value to the specified class. **/ public static Object coerce (Object pValue, Class pClass, Logger pLogger) throws ELException { if (pClass == String.class) { return coerceToString (pValue, pLogger); } else if (isPrimitiveNumberClass (pClass)) { return coerceToPrimitiveNumber (pValue, pClass, pLogger); } else if (pClass == Character.class || pClass == Character.TYPE) { return coerceToCharacter (pValue, pLogger); } else if (pClass == Boolean.class || pClass == Boolean.TYPE) { return coerceToBoolean (pValue, pLogger); } else { return coerceToObject (pValue, pClass, pLogger); } } //------------------------------------- /** * * Returns true if the given class is Byte, Short, Integer, Long, * Float, Double **/ static boolean isPrimitiveNumberClass (Class pClass) { return pClass == Byte.class || pClass == Byte.TYPE || pClass == Short.class || pClass == Short.TYPE || pClass == Integer.class || pClass == Integer.TYPE || pClass == Long.class || pClass == Long.TYPE || pClass == Float.class || pClass == Float.TYPE || pClass == Double.class || pClass == Double.TYPE; } //------------------------------------- /** * * Coerces the specified value to a String **/ public static String coerceToString (Object pValue, Logger pLogger) throws ELException { if (pValue == null) { return ""; } else if (pValue instanceof String) { return (String) pValue; } else { try { return pValue.toString (); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.TOSTRING_EXCEPTION, exc, pValue.getClass ().getName ()); } return ""; } } } //------------------------------------- /** * * Coerces a value to the given primitive number class **/ public static Number coerceToPrimitiveNumber (Object pValue, Class pClass, Logger pLogger) throws ELException { if (pValue == null || "".equals (pValue)) { return coerceToPrimitiveNumber (0, pClass); } else if (pValue instanceof Character) { char val = ((Character) pValue).charValue (); return coerceToPrimitiveNumber ((short) val, pClass); } else if (pValue instanceof Boolean) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.BOOLEAN_TO_NUMBER, pValue, pClass.getName ()); } return coerceToPrimitiveNumber (0, pClass); } else if (pValue.getClass () == pClass) { return (Number) pValue; } else if (pValue instanceof Number) { return coerceToPrimitiveNumber ((Number) pValue, pClass); } else if (pValue instanceof String) { try { return coerceToPrimitiveNumber ((String) pValue, pClass); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.STRING_TO_NUMBER_EXCEPTION, (String) pValue, pClass.getName ()); } return coerceToPrimitiveNumber (0, pClass); } } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COERCE_TO_NUMBER, pValue.getClass ().getName (), pClass.getName ()); } return coerceToPrimitiveNumber (0, pClass); } } //------------------------------------- /** * * Coerces a value to an Integer, returning null if the coercion * isn't possible. **/ public static Integer coerceToInteger (Object pValue, Logger pLogger) throws ELException { if (pValue == null) { return null; } else if (pValue instanceof Character) { return PrimitiveObjects.getInteger ((int) (((Character) pValue).charValue ())); } else if (pValue instanceof Boolean) { if (pLogger.isLoggingWarning ()) { pLogger.logWarning (Constants.BOOLEAN_TO_NUMBER, pValue, Integer.class.getName ()); } return PrimitiveObjects.getInteger (((Boolean) pValue).booleanValue () ? 1 : 0); } else if (pValue instanceof Integer) { return (Integer) pValue; } else if (pValue instanceof Number) { return PrimitiveObjects.getInteger (((Number) pValue).intValue ()); } else if (pValue instanceof String) { try { return Integer.valueOf ((String) pValue); } catch (Exception exc) { if (pLogger.isLoggingWarning ()) { pLogger.logWarning (Constants.STRING_TO_NUMBER_EXCEPTION, (String) pValue, Integer.class.getName ()); } return null; } } else { if (pLogger.isLoggingWarning ()) { pLogger.logWarning (Constants.COERCE_TO_NUMBER, pValue.getClass ().getName (), Integer.class.getName ()); } return null; } } //------------------------------------- /** * * Coerces a long to the given primitive number class **/ static Number coerceToPrimitiveNumber (long pValue, Class pClass) throws ELException { if (pClass == Byte.class || pClass == Byte.TYPE) { return PrimitiveObjects.getByte ((byte) pValue); } else if (pClass == Short.class || pClass == Short.TYPE) { return PrimitiveObjects.getShort ((short) pValue); } else if (pClass == Integer.class || pClass == Integer.TYPE) { return PrimitiveObjects.getInteger ((int) pValue); } else if (pClass == Long.class || pClass == Long.TYPE) { return PrimitiveObjects.getLong ((long) pValue); } else if (pClass == Float.class || pClass == Float.TYPE) { return PrimitiveObjects.getFloat ((float) pValue); } else if (pClass == Double.class || pClass == Double.TYPE) { return PrimitiveObjects.getDouble ((double) pValue); } else { return PrimitiveObjects.getInteger (0); } } //------------------------------------- /** * * Coerces a double to the given primitive number class **/ static Number coerceToPrimitiveNumber (double pValue, Class pClass) throws ELException { if (pClass == Byte.class || pClass == Byte.TYPE) { return PrimitiveObjects.getByte ((byte) pValue); } else if (pClass == Short.class || pClass == Short.TYPE) { return PrimitiveObjects.getShort ((short) pValue); } else if (pClass == Integer.class || pClass == Integer.TYPE) { return PrimitiveObjects.getInteger ((int) pValue); } else if (pClass == Long.class || pClass == Long.TYPE) { return PrimitiveObjects.getLong ((long) pValue); } else if (pClass == Float.class || pClass == Float.TYPE) { return PrimitiveObjects.getFloat ((float) pValue); } else if (pClass == Double.class || pClass == Double.TYPE) { return PrimitiveObjects.getDouble ((double) pValue); } else { return PrimitiveObjects.getInteger (0); } } //------------------------------------- /** * * Coerces a Number to the given primitive number class **/ static Number coerceToPrimitiveNumber (Number pValue, Class pClass) throws ELException { if (pClass == Byte.class || pClass == Byte.TYPE) { return PrimitiveObjects.getByte (pValue.byteValue ()); } else if (pClass == Short.class || pClass == Short.TYPE) { return PrimitiveObjects.getShort (pValue.shortValue ()); } else if (pClass == Integer.class || pClass == Integer.TYPE) { return PrimitiveObjects.getInteger (pValue.intValue ()); } else if (pClass == Long.class || pClass == Long.TYPE) { return PrimitiveObjects.getLong (pValue.longValue ()); } else if (pClass == Float.class || pClass == Float.TYPE) { return PrimitiveObjects.getFloat (pValue.floatValue ()); } else if (pClass == Double.class || pClass == Double.TYPE) { return PrimitiveObjects.getDouble (pValue.doubleValue ()); } else { return PrimitiveObjects.getInteger (0); } } //------------------------------------- /** * * Coerces a String to the given primitive number class **/ static Number coerceToPrimitiveNumber (String pValue, Class pClass) throws ELException { if (pClass == Byte.class || pClass == Byte.TYPE) { return Byte.valueOf (pValue); } else if (pClass == Short.class || pClass == Short.TYPE) { return Short.valueOf (pValue); } else if (pClass == Integer.class || pClass == Integer.TYPE) { return Integer.valueOf (pValue); } else if (pClass == Long.class || pClass == Long.TYPE) { return Long.valueOf (pValue); } else if (pClass == Float.class || pClass == Float.TYPE) { return Float.valueOf (pValue); } else if (pClass == Double.class || pClass == Double.TYPE) { return Double.valueOf (pValue); } else { return PrimitiveObjects.getInteger (0); } } //------------------------------------- /** * * Coerces a value to a Character **/ public static Character coerceToCharacter (Object pValue, Logger pLogger) throws ELException { if (pValue == null || "".equals (pValue)) { return PrimitiveObjects.getCharacter ((char) 0); } else if (pValue instanceof Character) { return (Character) pValue; } else if (pValue instanceof Boolean) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.BOOLEAN_TO_CHARACTER, pValue); } return PrimitiveObjects.getCharacter ((char) 0); } else if (pValue instanceof Number) { return PrimitiveObjects.getCharacter ((char) ((Number) pValue).shortValue ()); } else if (pValue instanceof String) { String str = (String) pValue; return PrimitiveObjects.getCharacter (str.charAt (0)); } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COERCE_TO_CHARACTER, pValue.getClass ().getName ()); } return PrimitiveObjects.getCharacter ((char) 0); } } //------------------------------------- /** * * Coerces a value to a Boolean **/ public static Boolean coerceToBoolean (Object pValue, Logger pLogger) throws ELException { if (pValue == null || "".equals (pValue)) { return Boolean.FALSE; } else if (pValue instanceof Boolean) { return (Boolean) pValue; } else if (pValue instanceof String) { String str = (String) pValue; try { return Boolean.valueOf (str); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.STRING_TO_BOOLEAN, exc, (String) pValue); } return Boolean.FALSE; } } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COERCE_TO_BOOLEAN, pValue.getClass ().getName ()); } return Boolean.TRUE; } } //------------------------------------- /** * * Coerces a value to the specified Class that is not covered by any * of the above cases **/ public static Object coerceToObject (Object pValue, Class pClass, Logger pLogger) throws ELException { if (pValue == null) { return null; } else if (pClass.isAssignableFrom (pValue.getClass ())) { return pValue; } else if (pValue instanceof String) { String str = (String) pValue; PropertyEditor pe = PropertyEditorManager.findEditor (pClass); if (pe == null) { if ("".equals (str)) { return null; } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.NO_PROPERTY_EDITOR, str, pClass.getName ()); } return null; } } try { pe.setAsText (str); return pe.getValue (); } catch (IllegalArgumentException exc) { if ("".equals (str)) { return null; } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.PROPERTY_EDITOR_ERROR, exc, pValue, pClass.getName ()); } return null; } } } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COERCE_TO_OBJECT, pValue.getClass ().getName (), pClass.getName ()); } return null; } } //------------------------------------- // Applying operators //------------------------------------- /** * * Performs all of the necessary type conversions, then calls on the * appropriate operator. **/ public static Object applyArithmeticOperator (Object pLeft, Object pRight, ArithmeticOperator pOperator, Logger pLogger) throws ELException { if (pLeft == null && pRight == null) { if (pLogger.isLoggingWarning ()) { pLogger.logWarning (Constants.ARITH_OP_NULL, pOperator.getOperatorSymbol ()); } return PrimitiveObjects.getInteger (0); } else if (isFloatingPointType (pLeft) || isFloatingPointType (pRight) || isFloatingPointString (pLeft) || isFloatingPointString (pRight)) { double left = coerceToPrimitiveNumber (pLeft, Double.class, pLogger). doubleValue (); double right = coerceToPrimitiveNumber (pRight, Double.class, pLogger). doubleValue (); return PrimitiveObjects.getDouble (pOperator.apply (left, right, pLogger)); } else { long left = coerceToPrimitiveNumber (pLeft, Long.class, pLogger). longValue (); long right = coerceToPrimitiveNumber (pRight, Long.class, pLogger). longValue (); return PrimitiveObjects.getLong (pOperator.apply (left, right, pLogger)); } } //------------------------------------- /** * * Performs all of the necessary type conversions, then calls on the * appropriate operator. **/ public static Object applyRelationalOperator (Object pLeft, Object pRight, RelationalOperator pOperator, Logger pLogger) throws ELException { if (isFloatingPointType (pLeft) || isFloatingPointType (pRight)) { double left = coerceToPrimitiveNumber (pLeft, Double.class, pLogger). doubleValue (); double right = coerceToPrimitiveNumber (pRight, Double.class, pLogger). doubleValue (); return PrimitiveObjects.getBoolean (pOperator.apply (left, right, pLogger)); } else if (isIntegerType (pLeft) || isIntegerType (pRight)) { long left = coerceToPrimitiveNumber (pLeft, Long.class, pLogger). longValue (); long right = coerceToPrimitiveNumber (pRight, Long.class, pLogger). longValue (); return PrimitiveObjects.getBoolean (pOperator.apply (left, right, pLogger)); } else if (pLeft instanceof String || pRight instanceof String) { String left = coerceToString (pLeft, pLogger); String right = coerceToString (pRight, pLogger); return PrimitiveObjects.getBoolean (pOperator.apply (left, right, pLogger)); } else if (pLeft instanceof Comparable) { try { int result = ((Comparable) pLeft).compareTo (pRight); return PrimitiveObjects.getBoolean (pOperator.apply (result, -result, pLogger)); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COMPARABLE_ERROR, exc, pLeft.getClass ().getName (), (pRight == null) ? "null" : pRight.getClass ().getName (), pOperator.getOperatorSymbol ()); } return Boolean.FALSE; } } else if (pRight instanceof Comparable) { try { int result = ((Comparable) pRight).compareTo (pLeft); return PrimitiveObjects.getBoolean (pOperator.apply (-result, result, pLogger)); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.COMPARABLE_ERROR, exc, pRight.getClass ().getName (), (pLeft == null) ? "null" : pLeft.getClass ().getName (), pOperator.getOperatorSymbol ()); } return Boolean.FALSE; } } else { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.ARITH_OP_BAD_TYPE, pOperator.getOperatorSymbol (), pLeft.getClass ().getName (), pRight.getClass ().getName ()); } return Boolean.FALSE; } } //------------------------------------- /** * * Performs all of the necessary type conversions, then calls on the * appropriate operator. **/ public static Object applyEqualityOperator (Object pLeft, Object pRight, EqualityOperator pOperator, Logger pLogger) throws ELException { if (pLeft == pRight) { return PrimitiveObjects.getBoolean (pOperator.apply (true, pLogger)); } else if (pLeft == null || pRight == null) { return PrimitiveObjects.getBoolean (pOperator.apply (false, pLogger)); } else if (isFloatingPointType (pLeft) || isFloatingPointType (pRight)) { double left = coerceToPrimitiveNumber (pLeft, Double.class, pLogger). doubleValue (); double right = coerceToPrimitiveNumber (pRight, Double.class, pLogger). doubleValue (); return PrimitiveObjects.getBoolean (pOperator.apply (left == right, pLogger)); } else if (isIntegerType (pLeft) || isIntegerType (pRight)) { long left = coerceToPrimitiveNumber (pLeft, Long.class, pLogger). longValue (); long right = coerceToPrimitiveNumber (pRight, Long.class, pLogger). longValue (); return PrimitiveObjects.getBoolean (pOperator.apply (left == right, pLogger)); } else if (pLeft instanceof Boolean || pRight instanceof Boolean) { boolean left = coerceToBoolean (pLeft, pLogger).booleanValue (); boolean right = coerceToBoolean (pRight, pLogger).booleanValue (); return PrimitiveObjects.getBoolean (pOperator.apply (left == right, pLogger)); } else if (pLeft instanceof String || pRight instanceof String) { String left = coerceToString (pLeft, pLogger); String right = coerceToString (pRight, pLogger); return PrimitiveObjects.getBoolean (pOperator.apply (left.equals (right), pLogger)); } else { try { return PrimitiveObjects.getBoolean (pOperator.apply (pLeft.equals (pRight), pLogger)); } catch (Exception exc) { if (pLogger.isLoggingError ()) { pLogger.logError (Constants.ERROR_IN_EQUALS, exc, pLeft.getClass ().getName (), pRight.getClass ().getName (), pOperator.getOperatorSymbol ()); } return Boolean.FALSE; } } } //------------------------------------- /** * * Returns true if the given Object is of a floating point type **/ public static boolean isFloatingPointType (Object pObject) { return pObject != null && isFloatingPointType (pObject.getClass ()); } //------------------------------------- /** * * Returns true if the given class is of a floating point type **/ public static boolean isFloatingPointType (Class pClass) { return pClass == Float.class || pClass == Float.TYPE || pClass == Double.class || pClass == Double.TYPE; } //------------------------------------- /** * * Returns true if the given string might contain a floating point * number - i.e., it contains ".", "e", or "E" **/ public static boolean isFloatingPointString (Object pObject) { if (pObject instanceof String) { String str = (String) pObject; int len = str.length (); for (int i = 0; i < len; i++) { char ch = str.charAt (i); if (ch == '.' || ch == 'e' || ch == 'E') { return true; } } return false; } else { return false; } } //------------------------------------- /** * * Returns true if the given Object is of an integer type **/ public static boolean isIntegerType (Object pObject) { return pObject != null && isIntegerType (pObject.getClass ()); } //------------------------------------- /** * * Returns true if the given class is of an integer type **/ public static boolean isIntegerType (Class pClass) { return pClass == Byte.class || pClass == Byte.TYPE || pClass == Short.class || pClass == Short.TYPE || pClass == Character.class || pClass == Character.TYPE || pClass == Integer.class || pClass == Integer.TYPE || pClass == Long.class || pClass == Long.TYPE; } //------------------------------------- }




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