com.sun.el
类 ValueExpressionLiteral

java.lang.Object
  javax.el.Expression
      javax.el.ValueExpression
          com.sun.el.ValueExpressionLiteral

所有已实现的接口：

Externalizable, Serializable

public final class ValueExpressionLiteral
extends ValueExpression
implements Externalizable

另请参见：

序列化表格

构造方法摘要

ValueExpressionLiteral()

ValueExpressionLiteral(Object value, Class expectedType)

方法摘要

boolean	equals(Object obj) Determines whether the specified object is equal to this Expression.
boolean	equals(ValueExpressionLiteral ve)
Class	getExpectedType() Returns the type the result of the expression will be coerced to after evaluation.
String	getExpressionString() Returns the original String used to create this Expression, unmodified.
Class	getType(ELContext context) Evaluates the expression relative to the provided context, and returns the most general type that is acceptable for an object to be passed as the value parameter in a future call to the ValueExpression.setValue(javax.el.ELContext, java.lang.Object) method.
Object	getValue(ELContext context) Evaluates the expression relative to the provided context, and returns the resulting value.
int	hashCode() Returns the hash code for this Expression.
boolean	isLiteralText() Returns whether this expression was created from only literal text.
boolean	isReadOnly(ELContext context) Evaluates the expression relative to the provided context, and returns true if a call to ValueExpression.setValue(javax.el.ELContext, java.lang.Object) will always fail.
void	readExternal(ObjectInput in)
void	setValue(ELContext context, Object value) Evaluates the expression relative to the provided context, and sets the result to the provided value.
void	writeExternal(ObjectOutput out)

从类 javax.el.ValueExpression 继承的方法

getValueReference

从类 java.lang.Object 继承的方法

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

构造方法详细信息

ValueExpressionLiteral

public ValueExpressionLiteral()

ValueExpressionLiteral

public ValueExpressionLiteral(Object value,
                              Class expectedType)

方法详细信息

getValue

public Object getValue(ELContext context)

从类 ValueExpression 复制的描述

Evaluates the expression relative to the provided context, and returns the resulting value.

The resulting value is automatically coerced to the type returned by getExpectedType(), which was provided to the ExpressionFactory when this expression was created.

指定者：

类 ValueExpression 中的 getValue

参数：

context - The context of this evaluation.

返回：

The result of the expression evaluation.

setValue

public void setValue(ELContext context,
                     Object value)

从类 ValueExpression 复制的描述

Evaluates the expression relative to the provided context, and sets the result to the provided value.

指定者：

类 ValueExpression 中的 setValue

参数：

context - The context of this evaluation.

value - The new value to be set.

isReadOnly

public boolean isReadOnly(ELContext context)

从类 ValueExpression 复制的描述

Evaluates the expression relative to the provided context, and returns true if a call to ValueExpression.setValue(javax.el.ELContext, java.lang.Object) will always fail.

指定者：

类 ValueExpression 中的 isReadOnly

参数：

context - The context of this evaluation.

返回：

true if the expression is read-only or false if not.

getType

public Class getType(ELContext context)

从类 ValueExpression 复制的描述

Evaluates the expression relative to the provided context, and returns the most general type that is acceptable for an object to be passed as the value parameter in a future call to the ValueExpression.setValue(javax.el.ELContext, java.lang.Object) method.

This is not always the same as getValue().getClass(). For example, in the case of an expression that references an array element, the getType method will return the element type of the array, which might be a superclass of the type of the actual element that is currently in the specified array element.

指定者：

类 ValueExpression 中的 getType

参数：

context - The context of this evaluation.

返回：

the most general acceptable type; otherwise undefined.

getExpectedType

public Class getExpectedType()

从类 ValueExpression 复制的描述

Returns the type the result of the expression will be coerced to after evaluation.

指定者：

类 ValueExpression 中的 getExpectedType

返回：

the expectedType passed to the ExpressionFactory.createValueExpression method that created this ValueExpression.

getExpressionString

public String getExpressionString()

从类 Expression 复制的描述

Returns the original String used to create this Expression, unmodified.

This is used for debugging purposes but also for the purposes of comparison (e.g. to ensure the expression in a configuration file has not changed).

This method does not provide sufficient information to re-create an expression. Two different expressions can have exactly the same expression string but different function mappings. Serialization should be used to save and restore the state of an Expression.

指定者：

类 Expression 中的 getExpressionString

返回：

The original expression String.

equals

public boolean equals(Object obj)

从类 Expression 复制的描述

Determines whether the specified object is equal to this Expression.

The result is true if and only if the argument is not null, is an Expression object that is the of the same type (ValueExpression or MethodExpression), and has an identical parsed representation.

Note that two expressions can be equal if their expression Strings are different. For example, ${fn1:foo()} and ${fn2:foo()} are equal if their corresponding FunctionMappers mapped fn1:foo and fn2:foo to the same method.

指定者：

类 Expression 中的 equals

参数：

obj - the Object to test for equality.

返回：

true if obj equals this Expression; false otherwise.

另请参见：

Hashtable, Object.equals(java.lang.Object)

equals

public boolean equals(ValueExpressionLiteral ve)

hashCode

public int hashCode()

从类 Expression 复制的描述

Returns the hash code for this Expression.

See the note in the Expression.equals(java.lang.Object) method on how two expressions can be equal if their expression Strings are different. Recall that if two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. Implementations must take special note and implement hashCode correctly.

指定者：

类 Expression 中的 hashCode

返回：

The hash code for this Expression.

另请参见：

Expression.equals(java.lang.Object), Hashtable, Object.hashCode()

isLiteralText

public boolean isLiteralText()

从类 Expression 复制的描述

Returns whether this expression was created from only literal text.

This method must return true if and only if the expression string this expression was created from contained no unescaped EL delimeters (${...} or #{...}).

指定者：

类 Expression 中的 isLiteralText

返回：

true if this expression was created from only literal text; false otherwise.

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

指定者：

接口 Externalizable 中的 writeExternal

抛出：

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

指定者：

接口 Externalizable 中的 readExternal

抛出：

IOException

ClassNotFoundException