/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* Portions Copyright Apache Software Foundation.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package javax.servlet.jsp.tagext;
import java.io.Reader;
import java.io.Writer;
import java.io.IOException;
import javax.servlet.jsp.*;
/**
* An encapsulation of the evaluation of the body of an action so it is
* available to a tag handler. BodyContent is a subclass of JspWriter.
*
* <p>
* Note that the content of BodyContent is the result of evaluation, so
* it will not contain actions and the like, but the result of their
* invocation.
*
* <p>
* BodyContent has methods to convert its contents into
* a String, to read its contents, and to clear the contents.
*
* <p>
* The buffer size of a BodyContent object is unbounded. A
* BodyContent object cannot be in autoFlush mode. It is not possible to
* invoke flush on a BodyContent object, as there is no backing stream.
*
* <p>
* Instances of BodyContent are created by invoking the pushBody and
* popBody methods of the PageContext class. A BodyContent is enclosed
* within another JspWriter (maybe another BodyContent object) following
* the structure of their associated actions.
*
* <p>
* A BodyContent is made available to a BodyTag through a setBodyContent()
* call. The tag handler can use the object until after the call to
* doEndTag().
*/
public abstract class BodyContent extends JspWriter {
/**
* Protected constructor.
*
* Unbounded buffer, no autoflushing.
*
* @param e the enclosing JspWriter
*/
protected BodyContent(JspWriter e) {
super(UNBOUNDED_BUFFER , false);
this.enclosingWriter = e;
}
/**
* Redefined flush() so it is not legal.
*
* <p>
* It is not valid to flush a BodyContent because there is no backing
* stream behind it.
*
* @throws IOException always thrown
*/
public void flush() throws IOException {
throw new IOException("Illegal to flush within a custom tag");
}
/**
* Clear the body without throwing any exceptions.
*/
public void clearBody() {
try {
this.clear();
} catch (IOException ex) {
// TODO -- clean this one up.
throw new Error("internal error!;");
}
}
/**
* Return the value of this BodyContent as a Reader.
*
* @return the value of this BodyContent as a Reader
*/
public abstract Reader getReader();
/**
* Return the value of the BodyContent as a String.
*
* @return the value of the BodyContent as a String
*/
public abstract String getString();
/**
* Write the contents of this BodyContent into a Writer.
* Subclasses may optimize common invocation patterns.
*
* @param out The writer into which to place the contents of
* this body evaluation
* @throws IOException if an I/O error occurred while writing the
* contents of this BodyContent to the given Writer
*/
public abstract void writeOut(Writer out) throws IOException;
/**
* Get the enclosing JspWriter.
*
* @return the enclosing JspWriter passed at construction time
*/
public JspWriter getEnclosingWriter() {
return enclosingWriter;
}
// private fields
private JspWriter enclosingWriter;
}
|