Expr (Resin 4.0.s170329)

java.lang.Object
- javax.el.Expression
- - javax.el.ValueExpression
  - - com.caucho.el.Expr

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

AbstractBooleanExpr, AddExpr, ArrayExpr, ArrayResolverExpr, BinaryExpr, CandiExpr, ConditionalExpr, ConditionalNullExpr, DivExpr, DoubleLiteral, FunctionExpr, IdExpr, ImplicitFieldExpr, ImplicitObjectExpr, InterpolateExpr, LongLiteral, MethodExpr, MinusExpr, ModExpr, MulExpr, NullLiteral, PathExpr, StaticMethodExpr, StringLiteral, SubExpr, UnaryExpr, ValueExpr
```
public abstract class Expr
extends ValueExpression
```
Abstract implementation class for an expression.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

protected static L10N L

protected static java.util.logging.Logger log

Fields
Modifier and Type	Field and Description
`protected static L10N`	`L`
`protected static java.util.logging.Logger`	`log`

Constructor Summary

Constructors
Constructor and Description

Expr()

Constructors
Constructor and Description
`Expr()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static java.lang.Object`	`coerceToType(java.lang.Object obj, java.lang.Class<?> targetType)`
`Expr`	`createField(Expr field)` Creates a field reference using this expression as the base object.
`Expr`	`createField(java.lang.String field)` Creates a field reference using this expression as the base object.
`Expr`	`createMethod(Expr[] args)` Creates a method call using this as the `obj.method` expression
`boolean`	`equals(java.lang.Object o)`
`static java.lang.Object`	`error(java.lang.Throwable e, ELContext env)` Returns an error object
`java.math.BigDecimal`	`evalBigDecimal(ELContext env)` Evaluate the expression, knowing the value should be a BigDecimal.
`java.math.BigInteger`	`evalBigInteger(ELContext env)` Evaluate the expression, knowing the value should be a BigInteger.
`boolean`	`evalBoolean(ELContext env)` Evaluate the expression, knowing the value should be a boolean.
`char`	`evalCharacter(ELContext env)` Evaluate the expression, knowing the value should be a string
`double`	`evalDouble(ELContext env)` Evaluate the expression, knowing the value should be a double.
`long`	`evalLong(ELContext env)` Evaluate the expression, knowing the value should be a long
`java.lang.Object`	`evalObject(ELContext env)` Evaluates the expression, returning an object.
`long`	`evalPeriod(ELContext env)` Evaluate the expression, knowing the value should be a period
`java.lang.String`	`evalString(ELContext env)` Evaluate the expression, knowing the value should be a string
`java.lang.String`	`evalStringWithNull(ELContext env)` Evaluate the expression, knowing the value should be a string
`java.lang.Class<?>`	`getExpectedType()`
`java.lang.String`	`getExpressionString()`
`MethodInfo`	`getMethodInfo(ELContext env, java.lang.Class<?> returnType, java.lang.Class<?>[] argTypes)` Evaluates the expression, returning an object.
`java.lang.Class<?>`	`getType(ELContext context)`
`abstract java.lang.Object`	`getValue(ELContext env)` Evaluates the expression, returning an object.
`int`	`hashCode()`
`static java.lang.Object`	`invocationError(java.lang.Throwable e)` Returns an error object
`java.lang.Object`	`invoke(ELContext env, java.lang.Class<?>[] argTypes, java.lang.Object[] args)` Evaluates the expression, returning an object.
`boolean`	`isConstant()` Returns true if the expression is constant.
`static boolean`	`isDouble(java.lang.Object o)` Returns true for a double or double-equivalent.
`protected static boolean`	`isDoubleString(java.lang.Object obj)`
`boolean`	`isLiteralText()` Returns true if the expression is literal text
`boolean`	`isReadOnly(ELContext env)` Returns true if the expression is read-only.
`boolean`	`print(JspWriter out, ELContext env, boolean escapeXml)` Evaluates directly to the output.
`boolean`	`print(WriteStream out, ELContext env, boolean escapeXml)` Evaluates directly to the output.
`void`	`printCreate(WriteStream os)` Generates the code to regenerate the expression.
`static void`	`printEscaped(WriteStream os, ReadStream is)` Write to the *.java stream escaping Java reserved characters.
`static void`	`printEscapedString(WriteStream os, java.lang.String string)` Write to the *.java stream escaping Java reserved characters.
`static void`	`setProperty(java.lang.Object target, java.lang.String property, java.lang.Object value)`
`void`	`setValue(ELContext env, java.lang.Object value)` Evaluates the expression, setting an object.
`static java.math.BigDecimal`	`toBigDecimal(java.lang.Object value, ELContext env)` Converts some unknown value to a big decimal
`static java.math.BigInteger`	`toBigInteger(java.lang.Object value, ELContext env)` Converts some unknown value to a big integer
`static boolean`	`toBoolean(java.lang.Object value, ELContext env)` Converts some unknown value to a boolean.
`static char`	`toCharacter(java.lang.Object value, ELContext env)` Converts some unknown value to a string.
`static java.lang.Class<?>`	`toClass(java.lang.Object value, ELContext env)` jsp/3019
`static double`	`toDouble(java.lang.Object value, ELContext env)` Converts some unknown value to a double.
`static java.lang.Object`	`toEnum(java.lang.Object obj, java.lang.Class<? extends java.lang.Enum> enumType)`
`static long`	`toLong(java.lang.Object value, ELContext env)` Converts some unknown value to a long.
`static void`	`toStream(JspWriter out, java.lang.Object value)` Write to the stream.
`static boolean`	`toStream(JspWriter out, java.lang.Object value, boolean isEscaped)` Write to the stream.
`static void`	`toStream(WriteStream out, java.lang.Object value)` Write to the stream.
`static void`	`toStreamEscaped(java.io.Writer out, java.lang.Object value)` Write to the stream.
`static void`	`toStreamEscaped(java.io.Writer out, java.io.Reader in)` Write to the stream escaping XML reserved characters.
`static void`	`toStreamEscaped(WriteStream out, java.lang.Object value)` Write to the stream escaping XML reserved characters.
`abstract java.lang.String`	`toString()`
`static java.lang.String`	`toString(boolean value, ELContext env)` Converts some unknown value to a string.
`static java.lang.String`	`toString(char value, ELContext env)` Converts some unknown value to a string.
`static java.lang.String`	`toString(double value, ELContext env)` Converts some unknown value to a string.
`static java.lang.String`	`toString(long value, ELContext env)` Converts some unknown value to a string.
`static java.lang.String`	`toString(java.lang.Object value, ELContext env)` Converts some unknown value to a string.
`static java.lang.String`	`toStringWithNull(java.lang.Object value, ELContext env)` Converts some unknown value to a string.

Methods inherited from class javax.el.ValueExpression
getValueReference

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

log

protected static final java.util.logging.Logger log

L
```
protected static final L10N L
```

Constructor Detail
- Expr
```
public Expr()
```

Method Detail

isConstant
```
public boolean isConstant()
```
Returns true if the expression is constant.

isReadOnly
```
public boolean isReadOnly(ELContext env)
```
Returns true if the expression is read-only.

Specified by:

isReadOnly in class ValueExpression

isLiteralText
```
public boolean isLiteralText()
```
Returns true if the expression is literal text

Specified by:

isLiteralText in class Expression

createField
```
public Expr createField(Expr field)
```
Creates a field reference using this expression as the base object.

Parameters:

field - the expression for the field.

createField
```
public Expr createField(java.lang.String field)
```
Creates a field reference using this expression as the base object.

Parameters:

field - the string reference for the field.

createMethod
```
public Expr createMethod(Expr[] args)
```
Creates a method call using this as the obj.method expression

Parameters:

args - the arguments for the method

getValue
```
public abstract java.lang.Object getValue(ELContext env)
                                   throws ELException
```
Evaluates the expression, returning an object.

Specified by:

getValue in class ValueExpression

Parameters:

env - the variable environment

Returns:

the value of the expression as an object

Throws:

ELException

getMethodInfo

public MethodInfo getMethodInfo(ELContext env,
                                java.lang.Class<?> returnType,
                                java.lang.Class<?>[] argTypes)
                         throws ELException

Evaluates the expression, returning an object.

Parameters:: env - the variable environment
Returns:: the value of the expression as an object
Throws:: ELException

invoke

public java.lang.Object invoke(ELContext env,
                               java.lang.Class<?>[] argTypes,
                               java.lang.Object[] args)
                        throws ELException

Evaluates the expression, returning an object.

Parameters:: env - the variable environment
Returns:: the value of the expression as an object
Throws:: ELException

evalObject
```
public final java.lang.Object evalObject(ELContext env)
                                  throws ELException
```
Evaluates the expression, returning an object.

Parameters:

env - the variable environment

Returns:

the value of the expression as an object

Throws:

ELException

evalBoolean
```
public boolean evalBoolean(ELContext env)
                    throws ELException
```
Evaluate the expression, knowing the value should be a boolean.

Parameters:

env - the variable environment

Returns:

the value of the expression as a boolean

Throws:

ELException

evalDouble
```
public double evalDouble(ELContext env)
                  throws ELException
```
Evaluate the expression, knowing the value should be a double.

Parameters:

env - the variable environment

Returns:

the value of the expression as a double

Throws:

ELException

evalLong
```
public long evalLong(ELContext env)
              throws ELException
```
Evaluate the expression, knowing the value should be a long

Parameters:

env - the variable environment

Returns:

the value of the expression as a double

Throws:

ELException

evalString
```
public java.lang.String evalString(ELContext env)
                            throws ELException
```
Evaluate the expression, knowing the value should be a string

Parameters:

env - the variable environment

Returns:

the value of the expression as a string

Throws:

ELException

evalStringWithNull
```
public java.lang.String evalStringWithNull(ELContext env)
                                    throws ELException
```
Evaluate the expression, knowing the value should be a string

Parameters:

env - the variable environment

Returns:

the value of the expression as a string

Throws:

ELException

evalCharacter
```
public char evalCharacter(ELContext env)
                   throws ELException
```
Evaluate the expression, knowing the value should be a string

Parameters:

env - the variable environment

Returns:

the value of the expression as a string

Throws:

ELException

evalPeriod
```
public long evalPeriod(ELContext env)
                throws ELException
```
Evaluate the expression, knowing the value should be a period

Parameters:

env - the variable environment

Returns:

the value of the expression as a period

Throws:

ELException

evalBigInteger
```
public java.math.BigInteger evalBigInteger(ELContext env)
                                    throws ELException
```
Evaluate the expression, knowing the value should be a BigInteger.

Parameters:

env - the variable environment

Returns:

the value of the expression as a BigInteger

Throws:

ELException

evalBigDecimal
```
public java.math.BigDecimal evalBigDecimal(ELContext env)
                                    throws ELException
```
Evaluate the expression, knowing the value should be a BigDecimal.

Parameters:

env - the variable environment

Returns:

the value of the expression as a BigDecimal

Throws:

ELException

setValue

public void setValue(ELContext env,
                     java.lang.Object value)
              throws PropertyNotFoundException,
                     PropertyNotWritableException,
                     ELException

Evaluates the expression, setting an object.

Specified by:: setValue in class ValueExpression
Parameters:: env - the variable environment
Throws:: PropertyNotFoundException; PropertyNotWritableException; ELException

print
```
public boolean print(WriteStream out,
                     ELContext env,
                     boolean escapeXml)
              throws java.io.IOException,
                     ELException
```
Evaluates directly to the output. The method returns true if the default value should be printed instead.

Parameters:

out - the output writer

env - the variable environment

escapeXml - if true, escape reserved XML

Returns:

true if the object is null, otherwise false

Throws:

java.io.IOException

ELException

print
```
public boolean print(JspWriter out,
                     ELContext env,
                     boolean escapeXml)
              throws java.io.IOException,
                     ELException
```
Evaluates directly to the output. The method returns true if the default value should be printed instead.

Parameters:

out - the output writer

env - the variable environment

escapeXml - 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
```
Generates the code to regenerate the expression.

Parameters:

os - the stream to the *.java page

Throws:

java.io.IOException

getExpressionString
```
public java.lang.String getExpressionString()
```
Specified by:

getExpressionString in class Expression

getExpectedType
```
public java.lang.Class<?> getExpectedType()
```
Specified by:

getExpectedType in class ValueExpression

getType

public java.lang.Class<?> getType(ELContext context)
                           throws PropertyNotFoundException,
                                  ELException

Specified by:: getType in class ValueExpression
Throws:: PropertyNotFoundException; ELException

isDouble
```
public static boolean isDouble(java.lang.Object o)
```
Returns true for a double or double-equivalent.