org.apache.struts2.views.jsp

## Class StrutsBodyTagSupport

- java.lang.Object
- - javax.servlet.jsp.tagext.TagSupport
  - - javax.servlet.jsp.tagext.BodyTagSupport
    - - org.apache.struts2.views.jsp.StrutsBodyTagSupport

- All Implemented Interfaces:
    Serializable, javax.servlet.jsp.tagext.BodyTag, javax.servlet.jsp.tagext.IterationTag, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag
  Direct Known Subclasses:
    ComponentTagSupport, IteratorGeneratorTag, SortIteratorTag, SubsetIteratorTag

      public class StrutsBodyTagSupport
      extends javax.servlet.jsp.tagext.BodyTagSupport

  Contains common functionalities for Struts JSP Tags.
  See Also:
    Serialized Form

- - ### Field Summary

    - ### Fields inherited from class javax.servlet.jsp.tagext.BodyTagSupport

      `bodyContent`

    - ### Fields inherited from class javax.servlet.jsp.tagext.TagSupport

      `id, pageContext`

    - ### Fields inherited from interface javax.servlet.jsp.tagext.BodyTag

      `EVAL_BODY_BUFFERED, EVAL_BODY_TAG`

    - ### Fields inherited from interface javax.servlet.jsp.tagext.IterationTag

      `EVAL_BODY_AGAIN`

    - ### Fields inherited from interface javax.servlet.jsp.tagext.Tag

      `EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `StrutsBodyTagSupport()`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected void` | `clearTagStateForTagPoolingServers()` Provide a mechanism to clear tag state, to handle servlet container JSP tag pooling behaviour with some servers, such as Glassfish.
    `int` | `doEndTag()`
    `protected String` | `findString(String expr)`
    `protected Object` | `findValue(String expr)`
    `protected Object` | `findValue(String expr, Class<?> toType)`
    `protected String` | `getBody()`
    `protected boolean` | `getPerformClearTagStateForTagPoolingServers()` Allow descendant tags to check if the tag state should be cleared during `doEndTag()` processing,
    `protected ValueStack` | `getStack()`
    `void` | `release()` Release state for a Struts JSP Tag handler.
    `void` | `setPerformClearTagStateForTagPoolingServers(boolean performClearTagStateForTagPoolingServers)` Request that the tag state be cleared during `doEndTag()` processing, which may help with certain edge cases with tag logic running on servers that implement JSP Tag Pooling.
    `protected String` | `toString(Throwable t)`

    - ### Methods inherited from class javax.servlet.jsp.tagext.BodyTagSupport

      `doAfterBody, doInitBody, doStartTag, getBodyContent, getPreviousOut, setBodyContent`

    - ### Methods inherited from class javax.servlet.jsp.tagext.TagSupport

      `findAncestorWithClass, getId, getParent, getValue, getValues, removeValue, setId, setPageContext, setParent, setValue`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface javax.servlet.jsp.tagext.Tag

      `getParent, setPageContext, setParent`

- - ### Constructor Detail

    - #### StrutsBodyTagSupport

          public StrutsBodyTagSupport()

  - ### Method Detail

    - #### getStack

          protected ValueStack getStack()

    - #### findString

          protected String findString(String expr)

    - #### findValue

          protected Object findValue(String expr)

    - #### findValue

          protected Object findValue(String expr,
                                     Class<?> toType)

    - #### toString

          protected String toString(Throwable t)

    - #### getBody

          protected String getBody()

    - #### doEndTag

          public int doEndTag()
                       throws javax.servlet.jsp.JspException

      Specified by:
        `doEndTag` in interface `javax.servlet.jsp.tagext.Tag`
      Overrides:
        `doEndTag` in class `javax.servlet.jsp.tagext.BodyTagSupport`
      Throws:
        `javax.servlet.jsp.JspException`

    - #### release

          public void release()

      Release state for a Struts JSP Tag handler.

      According to the JSP API documentation, the page compiler guarantees that the release() method will be invoked on the Tag handler before releasing it to the GC (garbage collector). It does not specify when the release() call will be made, though, and timing likely depends on the implementation of the JSP/servlet engine being used.

      Specified by:
        `release` in interface `javax.servlet.jsp.tagext.Tag`
      Overrides:
        `release` in class `javax.servlet.jsp.tagext.BodyTagSupport`

    - #### setPerformClearTagStateForTagPoolingServers

          public void setPerformClearTagStateForTagPoolingServers(boolean performClearTagStateForTagPoolingServers)

      Request that the tag state be cleared during `doEndTag()` processing, which may help with certain edge cases with tag logic running on servers that implement JSP Tag Pooling. Note: Even though the Tag classes extend this class `StrutsBodyTagSupport`, and this method `setPerformClearTagStateForTagPoolingServers(boolean)` exists in the method hierarchy, the JSP processing requires us to explicitly override it in every Tag class in order for the Tag handler method to be visible to the JSP processing. Defining a setter in the superclass alone is insufficient (results in "Cannot find a setter method for the attribute").

      See `clearTagStateForTagPoolingServers()` for additional details. Warning: Setting this value to true may allow for the desired behaviour, but doing so may violate the JSP specification. Set to true at your own risk.

      Parameters:
        `performClearTagStateForTagPoolingServers` - true if tag state should be cleared, false otherwise.

    - #### getPerformClearTagStateForTagPoolingServers

          protected boolean getPerformClearTagStateForTagPoolingServers()

      Allow descendant tags to check if the tag state should be cleared during `doEndTag()` processing,
      Returns:
        true if tag state should be cleared, false (default) otherwise.

    - #### clearTagStateForTagPoolingServers

          protected void clearTagStateForTagPoolingServers()

      Provide a mechanism to clear tag state, to handle servlet container JSP tag pooling behaviour with some servers, such as Glassfish.

      Usage: Override this method in descendant classes to clear any state that might cause issues should the servlet container re-use a cached instance of the tag object. If the descendant class does not declare any new field members then it should not be strictly necessary to call this method there. Typically that means calling the ancestor's `ComponentTagSupport.clearTagStateForTagPoolingServers()` method first, then resetting instance variables at the current level to their default state.

      Note: If the descendant overrides `doEndTag()`, and does not call super.doEndTag(), then the descendant should call this method in the descendant doEndTag() method to ensure consistent clearing of tag state.

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