| /* |
| * Copyright 2004 The Apache Software Foundation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| 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; |
| } |