com.caucho.el

Class NullLiteral

java.lang.Object

ValueExpression

com.caucho.el.Expr

com.caucho.el.NullLiteral

public class NullLiteral
extends Expr

Represents a null literal expression.

Field Summary

Fields inherited from class com.caucho.el.Expr

L, log

Constructor Summary

Constructors

Constructor and Description
NullLiteral() Create the literal.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o) Returns true for equal strings.
java.lang.Object	getValue(ELContext env) Evaluate the expression as an object.
boolean	isConstant() Returns true if the expression is constant.
boolean	print(WriteStream out, ELContext env, boolean isEscaped) Evalutes directly to the output.
void	printCreate(WriteStream os) Prints the code to create an LongLiteral.
java.lang.String	toString() Returns a printable view.

Methods inherited from class com.caucho.el.Expr

coerceToType, createField, createField, createMethod, error, evalBigDecimal, evalBigInteger, evalBoolean, evalCharacter, evalDouble, evalLong, evalObject, evalPeriod, evalString, evalStringWithNull, getExpectedType, getExpressionString, getMethodInfo, getType, hashCode, invocationError, invoke, isDouble, isDoubleString, isLiteralText, isReadOnly, printEscaped, printEscapedString, setProperty, setValue, toBigDecimal, toBigInteger, toBoolean, toCharacter, toClass, toDouble, toEnum, toLong, toStream, toStream, toStream, toStreamEscaped, toStreamEscaped, toStreamEscaped, toString, toString, toString, toString, toString, toStringWithNull

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NullLiteral

public NullLiteral()

Create the literal.

Method Detail

isConstant

public boolean isConstant()

Returns true if the expression is constant.

Overrides:

isConstant in class Expr

getValue

public java.lang.Object getValue(ELContext env)
                          throws ELException

Evaluate the expression as an object.

Specified by:

getValue in class Expr

Parameters:

env - the variable environment

Returns:

null

Throws:

ELException

print

public boolean print(WriteStream out,
                     ELContext env,
                     boolean isEscaped)
              throws java.io.IOException,
                     ELException

Evalutes directly to the output.

Overrides:

print in class Expr

Parameters:

out - the output writer

env - the variable environment

isEscaped - if true, escape reserved XML

Returns:

true if the object is null, otherwise false

Throws:

java.io.IOException

ELException

printCreate

public void printCreate(WriteStream os)
                 throws java.io.IOException

Prints the code to create an LongLiteral.

Overrides:

printCreate in class Expr

Parameters:

os - the stream to the *.java page

Throws:

java.io.IOException

equals

public boolean equals(java.lang.Object o)

Returns true for equal strings.

Overrides:

equals in class Expr

toString

public java.lang.String toString()

Returns a printable view.

Specified by:

toString in class Expr