ValueBinding (Java EE 5)

ValueBinding 是一个对象，可以用来访问操作或值绑定表达式所表示的属性。通过调用此 Web 应用程序的 javax.faces.application.Application 实例的 createValueBinding() 方法，可以获得用于特定值绑定的不可变 ValueBinding。

public abstract class ValueBinding

extends Object

ValueBinding is an object that can be used to access the property represented by an action or value binding expression. An immutable ValueBinding for a particular value binding can be acquired by calling the createValueBinding() method of the Application instance for this web application.

public ValueBinding()

英文文档：

ValueBinding

public ValueBinding()

Deprecated. 

abstract public Object getValue(FacesContext context) throws EvaluationException, PropertyNotFoundException

相对于指定的 FacesContext，返回此 ValueBinding 表示的属性的值。

context	当前请求的 FacesContext
Throws	EvaluationException: 如果获取值时抛出异常（抛出的异常必须作为此异常的 cause 属性包含在内）
Throws	NullPointerException: 如果 context 为 null
Throws	PropertyNotFoundException: 如果指定的属性名称不存在，或者不可读

英文文档：

getValue

public abstract Object getValue(FacesContext context)
                         throws EvaluationException,
                                PropertyNotFoundException

Deprecated. 

Return the value of the property represented by this ValueBinding, relative to the specified FacesContext.

Parameters:

context - FacesContext for the current request

Throws:

EvaluationException - if an exception is thrown while getting the value (the thrown exception must be included as the cause property of this exception)

NullPointerException - if context is null

PropertyNotFoundException - if a specified property name does not exist, or is not readable

abstract public void setValue(FacesContext context, Object value) throws EvaluationException, PropertyNotFoundException

相对于指定的 FacesContext，设置此 ValueBinding 表示的属性的值。

context	当前请求的 FacesContext
value	要设置的新值
Throws	EvaluationException: 如果在设置值时抛出异常（抛出的异常必须作为此异常的 cause 属性包含在内）
Throws	NullPointerException: 如果 context 为 null
Throws	PropertyNotFoundException: 如果指定的属性名称不存在，或者不可写

英文文档：

setValue

public abstract void setValue(FacesContext context,
                              Object value)
                       throws EvaluationException,
                              PropertyNotFoundException

Deprecated. 

Set the value of the property represented by this ValueBinding, relative to the specified FacesContext.

Parameters:

context - FacesContext for the current request

value - The new value to be set

Throws:

EvaluationException - if an exception is thrown while setting the value (the thrown exception must be included as the cause property of this exception)

NullPointerException - if context is null

PropertyNotFoundException - if a specified property name does not exist, or is not writeable

abstract public boolean isReadOnly(FacesContext context) throws EvaluationException, PropertyNotFoundException

如果已知指定属性的指定属性不可变，则返回 true；否则返回 false。

context	当前请求的 FacesContext
Throws	EvaluationException: 如果获取属性的描述期间抛出异常（抛出的异常必须作为此异常的 cause 属性包含在内）
Throws	NullPointerException: 如果 context 为 null
Throws	PropertyNotFoundException: 如果指定的属性名称不存在

英文文档：

isReadOnly

public abstract boolean isReadOnly(FacesContext context)
                            throws EvaluationException,
                                   PropertyNotFoundException

Deprecated. 

Return true if the specified property of the specified property is known to be immutable; otherwise, return false.

Parameters:

context - FacesContext for the current request

Throws:

EvaluationException - if an exception is thrown while getting the description of the property (the thrown exception must be included as the cause property of this exception)

NullPointerException - if context is null

PropertyNotFoundException - if a specified property name does not exist

abstract public Class<T> getType(FacesContext context) throws EvaluationException, PropertyNotFoundException

相对于指定的 FacesContext，返回此 ValueBinding 表示的属性的类型。

context	当前请求的 FacesContext
Throws	EvaluationException: 如果获取属性的描述期间抛出异常（抛出的异常必须作为此异常的 cause 属性包含在内）
Throws	NullPointerException: 如果 context 为 null
Throws	PropertyNotFoundException: 如果指定的属性名称不存在

英文文档：

getType

public abstract Class getType(FacesContext context)
                       throws EvaluationException,
                              PropertyNotFoundException

Deprecated. 

Return the type of the property represented by this ValueBinding, relative to the specified FacesContext.

Parameters:

context - FacesContext for the current request

Throws:

EvaluationException - if an exception is thrown while getting the description of the property (the thrown exception must be included as the cause property of this exception)

NullPointerException - if context is null

PropertyNotFoundException - if a specified property name does not exist

public String getExpressionString()

返回据以构建 ValueBinding 的表达式 String（可能为 null），包括分界符。

英文文档：

getExpressionString

public String getExpressionString()

Deprecated. 

Return the (possibly null) expression String, including the delimiters, from which this ValueBinding was built.

Copyright 2007 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.