ConverterELTag (Java EE 5)

ConverterELTag 是所有满足以下条件的 JSP 自定义操作的基类：对最接近的标记实例（其实现类为 UIComponentClassicTagBase 的子类）所关联的 ValueHolder 创建并注册一个 Converter 实例。为了避免在重新显示页面时创建重复的实例，仅当执行当前页面期间拥有它的 UIComponentTag 创建相应的 UIComponent 时才创建和注册 Converter。

此类可以用作支持特定 Converter 子类的标记实例的基类。

此类的子类必须实现 createConverter() 方法，该方法创建并返回 Converter 实例。指定此 Converter 行为的任何配置属性必须通过 createConverter() 方法进行了设置。这通常发生在复制标记实例相应的属性值时。

此标记没有对当前创建的页面创建任何输出。它仅用于创建 Converter 时发生的副作用。

ConverterELTag is a base class for all JSP custom actions that create and register a Converter instance on the ValueHolder associated with our most immediate surrounding instance of a tag whose implementation class is a subclass of UIComponentClassicTagBase. To avoid creating duplicate instances when a page is redisplayed, creation and registration of a Converter occurs only if the corresponding UIComponent was created (by the owning UIComponentTag) during the execution of the current page.

This class may be used as a base class for tag instances that support specific Converter subclasses.

Subclasses of this class must implement the createConverter() method, which creates and returns a Converter instance. Any configuration properties that specify behavior of this Converter must have been set by the createConverter() method. Generally, this occurs by copying corresponding attribute values on the tag instance.

This tag creates no output to the page currently being created. It is used solely for the side effect of Converter creation.

See Also:

Serialized Form

public ConverterELTag()

英文文档：

ConverterELTag

public ConverterELTag()

public int doStartTag() throws JspException

创建指定 Converter 类的新实例，如果执行包含它的 JSP 页面时创建了 UIComponent 实例，则向最接近的 UIComponentClassicTagBase 实例所关联的 UIComponent 实例注册该新实例。如果 UIComponent 的 localValue 为 String，可尝试转换它。

doStartTag

public int doStartTag()
               throws JspException

Create a new instance of the specified Converter class, and register it with the UIComponent instance associated with our most immediately surrounding UIComponentClassicTagBase instance, if the UIComponent instance was created by this execution of the containing JSP page. If the localValue of the UIComponent is a String, attempt to convert it.

abstract protected Converter createConverter() throws JspException

创建并返回一个新的 Converter，以向接近的 UIComponent 注册。

Throws

JspException: 如果无法创建新的实例

英文文档：

createConverter

protected abstract Converter createConverter()
                                      throws JspException

Create and return a new Converter to be registered on our surrounding UIComponent.

Throws:

JspException - if a new instance cannot be created

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