https://tomcat.apache.org/: JSP package 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;


A base class for defining tag handlers implementing BodyTag.


The BodyTagSupport class implements the BodyTag interface and adds additional
convenience methods including getter methods for the bodyContent property and
methods to get at the previous out JspWriter.


Many tag handlers will extend BodyTagSupport and only redefine a few methods.

/**
 * A base class for defining tag handlers implementing BodyTag.
 * <p>
 * The BodyTagSupport class implements the BodyTag interface and adds additional
 * convenience methods including getter methods for the bodyContent property and
 * methods to get at the previous out JspWriter.
 * <p>
 * Many tag handlers will extend BodyTagSupport and only redefine a few methods.
 */
public class BodyTagSupport extends TagSupport implements BodyTag {

    private static final long serialVersionUID = -7235752615580319833L;

    
Default constructor, all subclasses are required to only define a public
constructor with the same signature, and to call the superclass
constructor. This constructor is called by the code generated by the JSP
translator.

/**
     * Default constructor, all subclasses are required to only define a public
     * constructor with the same signature, and to call the superclass
     * constructor. This constructor is called by the code generated by the JSP
     * translator.
     */
    public BodyTagSupport() {
        super();
    }

    
Default processing of the start tag returning EVAL_BODY_BUFFERED.

Throws:
  • JspException – 
            if an error occurred while processing this tag
See Also:
Returns:EVAL_BODY_BUFFERED
/**
     * Default processing of the start tag returning EVAL_BODY_BUFFERED.
     *
     * @return EVAL_BODY_BUFFERED
     * @throws JspException
     *             if an error occurred while processing this tag
     * @see BodyTag#doStartTag
     */
    @Override
    public int doStartTag() throws JspException {
        return EVAL_BODY_BUFFERED;
    }

    
Default processing of the end tag returning EVAL_PAGE.

Throws:
  • JspException – 
            if an error occurred while processing this tag
See Also:
Returns:EVAL_PAGE
/**
     * Default processing of the end tag returning EVAL_PAGE.
     *
     * @return EVAL_PAGE
     * @throws JspException
     *             if an error occurred while processing this tag
     * @see Tag#doEndTag
     */
    @Override
    public int doEndTag() throws JspException {
        return super.doEndTag();
    }

    // Actions related to body evaluation

    
Prepare for evaluation of the body: stash the bodyContent away.

Params:
  • b – 
           the BodyContent
See Also:
/**
     * Prepare for evaluation of the body: stash the bodyContent away.
     *
     * @param b
     *            the BodyContent
     * @see #doAfterBody
     * @see #doInitBody()
     * @see BodyTag#setBodyContent
     */
    @Override
    public void setBodyContent(BodyContent b) {
        this.bodyContent = b;
    }

    
Prepare for evaluation of the body just before the first body evaluation:
no action.

Throws:
  • JspException – 
            if an error occurred while processing this tag
See Also:
/**
     * Prepare for evaluation of the body just before the first body evaluation:
     * no action.
     *
     * @throws JspException
     *             if an error occurred while processing this tag
     * @see #setBodyContent
     * @see #doAfterBody
     * @see BodyTag#doInitBody
     */
    @Override
    public void doInitBody() throws JspException {
        // NOOP by default
    }

    
After the body evaluation: do not reevaluate and continue with the page.
By default nothing is done with the bodyContent data (if any).

Throws:
  • JspException – 
            if an error occurred while processing this tag
See Also:
Returns:SKIP_BODY
/**
     * After the body evaluation: do not reevaluate and continue with the page.
     * By default nothing is done with the bodyContent data (if any).
     *
     * @return SKIP_BODY
     * @throws JspException
     *             if an error occurred while processing this tag
     * @see #doInitBody
     * @see BodyTag#doAfterBody
     */
    @Override
    public int doAfterBody() throws JspException {
        return SKIP_BODY;
    }

    
Release state.

See Also:
  • release.release
/**
     * Release state.
     *
     * @see Tag#release
     */
    @Override
    public void release() {
        bodyContent = null;

        super.release();
    }

    
Get current bodyContent.

Returns:the body content.
/**
     * Get current bodyContent.
     *
     * @return the body content.
     */
    public BodyContent getBodyContent() {
        return bodyContent;
    }

    
Get surrounding out JspWriter.

Returns:the enclosing JspWriter, from the bodyContent.
/**
     * Get surrounding out JspWriter.
     *
     * @return the enclosing JspWriter, from the bodyContent.
     */
    public JspWriter getPreviousOut() {
        return bodyContent.getEnclosingWriter();
    }

    // protected fields

    
The current BodyContent for this BodyTag.

/**
     * The current BodyContent for this BodyTag.
     */
    protected transient BodyContent bodyContent;
}