org.apache.el.lang
Class ELSupport

java.lang.Object
  org.apache.el.lang.ELSupport

Direct Known Subclasses:

SimpleNode

public class ELSupport
extends java.lang.Object

A helper class that implements the EL Specification

Author:

Jacob Hookom [jacob@hookom.net]

ELSupport

public ELSupport()

throwUnhandled

public static final void throwUnhandled(java.lang.Object base,
                                        java.lang.Object property)
                                 throws javax.el.ELException

Throws:

javax.el.ELException

compare

public static final int compare(java.lang.Object obj0,
                                java.lang.Object obj1)
                         throws javax.el.ELException

Compare two objects, after coercing to the same type if appropriate. If the objects are identical, or they are equal according to equals(Object, Object) then return 0. If either object is a BigDecimal, then coerce both to BigDecimal first. Similarly for Double(Float), BigInteger, and Long(Integer, Char, Short, Byte). Otherwise, check that the first object is an instance of Comparable, and compare against the second object. If that is null, return 1, otherwise return the result of comparing against the second object. Similarly, if the second object is Comparable, if the first is null, return -1, else return the result of comparing against the first object. A null object is considered as:

• ZERO when compared with Numbers
• the empty string for String compares
• Otherwise null is considered to be lower than anything else.

Parameters:

obj0 - first object

obj1 - second object

Returns:

-1, 0, or 1 if this object is less than, equal to, or greater than val.

Throws:

javax.el.ELException - if neither object is Comparable

java.lang.ClassCastException - if the objects are not mutually comparable

equals

public static final boolean equals(java.lang.Object obj0,
                                   java.lang.Object obj1)
                            throws javax.el.ELException

Compare two objects for equality, after coercing to the same type if appropriate. If the objects are identical (including both null) return true. If either object is null, return false. If either object is Boolean, coerce both to Boolean and check equality. Similarly for Enum, String, BigDecimal, Double(Float), Long(Integer, Short, Byte, Character) Otherwise default to using Object.equals().

Parameters:

obj0 - the first object

obj1 - the second object

Returns:

true if the objects are equal

Throws:

javax.el.ELException

coerceToEnum

public static final java.lang.Enum<?> coerceToEnum(java.lang.Object obj,
                                                   java.lang.Class type)

coerceToBoolean

public static final java.lang.Boolean coerceToBoolean(java.lang.Object obj)
                                               throws javax.el.ELException

Convert an object to Boolean. Null and empty string are false.

Parameters:

obj - the object to convert

Returns:

the Boolean value of the object

Throws:

javax.el.ELException - if object is not Boolean or String

coerceToCharacter

public static final java.lang.Character coerceToCharacter(java.lang.Object obj)
                                                   throws javax.el.ELException

Throws:

javax.el.ELException

coerceToNumber

public static final java.lang.Number coerceToNumber(java.lang.Object obj)

coerceToNumber

protected static final java.lang.Number coerceToNumber(java.lang.Number number,
                                                       java.lang.Class<?> type)
                                                throws javax.el.ELException

Throws:

javax.el.ELException

coerceToNumber

public static final java.lang.Number coerceToNumber(java.lang.Object obj,
                                                    java.lang.Class<?> type)
                                             throws javax.el.ELException

Throws:

javax.el.ELException

coerceToNumber

protected static final java.lang.Number coerceToNumber(java.lang.String val,
                                                       java.lang.Class<?> type)
                                                throws javax.el.ELException

Throws:

javax.el.ELException

coerceToString

public static final java.lang.String coerceToString(java.lang.Object obj)

checkType

public static final void checkType(java.lang.Object obj,
                                   java.lang.Class type)
                            throws javax.el.ELException

Throws:

javax.el.ELException

coerceToType

public static final java.lang.Object coerceToType(java.lang.Object obj,
                                                  java.lang.Class<?> type)
                                           throws javax.el.ELException

Throws:

javax.el.ELException

containsNulls

public static final boolean containsNulls(java.lang.Object[] obj)

isBigDecimalOp

public static final boolean isBigDecimalOp(java.lang.Object obj0,
                                           java.lang.Object obj1)

isBigIntegerOp

public static final boolean isBigIntegerOp(java.lang.Object obj0,
                                           java.lang.Object obj1)

isDoubleOp

public static final boolean isDoubleOp(java.lang.Object obj0,
                                       java.lang.Object obj1)

isDoubleStringOp

public static final boolean isDoubleStringOp(java.lang.Object obj0,
                                             java.lang.Object obj1)

isLongOp

public static final boolean isLongOp(java.lang.Object obj0,
                                     java.lang.Object obj1)

isStringFloat

public static final boolean isStringFloat(java.lang.String str)

toFloat

public static final java.lang.Number toFloat(java.lang.String value)

toNumber

public static final java.lang.Number toNumber(java.lang.String value)