Class TagLibraryValidator

java.lang.Object
javax.servlet.jsp.tagext.TagLibraryValidator

public abstract class TagLibraryValidator extends Object
Translation-time validator class for a JSP page. A validator operates on the XML document associated with the JSP page.

The TLD file associates a TagLibraryValidator class and some init arguments with a tag library.

The JSP container is reponsible for locating an appropriate instance of the appropriate subclass by

  • new a fresh instance, or reuse an available one
  • invoke the setInitParams(Map) method on the instance
once initialized, the validate(String, String, PageData) method will be invoked, where the first two arguments are the prefix and uri arguments used in the taglib directive.

A TagLibraryValidator instance may create auxiliary objects internally to perform the validation (e.g. an XSchema validator) and may reuse it for all the pages in a given translation run.

The JSP container is not guaranteed to serialize invocations of validate() method, and TagLibraryValidators should perform any synchronization they may require.

A JSP container may optionally support a jsp:id attribute to provide higher quality validation errors. When supported, the container will track the JSP pages as passed to the container, and will assign to each element a unique "id", which is passed as the value of the jsp:id attribute. Each XML element in the XML view available will be extended with this attribute. The TagLibraryValidator can then use the attribute in one or more ValidationMessage objects. The container then, in turn, can use these values to provide more precise information on the location of an error.

  • Constructor Details

    • TagLibraryValidator

      public TagLibraryValidator()
  • Method Details

    • setInitParameters

      public void setInitParameters(Map map)
      Set the init data in the TLD for this validator. Parameter names are keys, and parameter values are the values.
      Parameters:
      initMap - A Map describing the init parameters
    • getInitParameters

      public Map getInitParameters()
      Get the init parameters data as an immutable Map. Parameter names are keys, and parameter values are the values.
      Returns:
      The init parameters as an immutable map.
    • validate

      public ValidationMessage[] validate(String prefix, String uri, PageData page)
      Validate a JSP page. This will get invoked once per directive in the JSP page. This method will return null if the page is valid; otherwise the method should return an array of ValidationMessage objects. An array of length zero is also interpreted as no errors.
      Parameters:
      prefix - the value of the prefix argument in the directive
      uri - the value of the uri argument in the directive
      thePage - the JspData page object
      Returns:
      A null object, or zero length array if no errors, an array of ValidationMessages otherwise.
    • release

      public void release()
      Release any data kept by this instance for validation purposes