htmlattributemap.java

一个比较不错的java分页标签,有源代码,开发者 可以学习学习

/**
 * Licensed under the Artistic License; you may not use this file
 * except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://displaytag.sourceforge.net/license.html
 *
 * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
package org.displaytag.util;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;


/**
 * Extends Map providing only a different toString() method which can be used in printing attributes inside an html tag.
 * @author Fabrizio Giustina
 * @version $Revision: 720 $ ($Author: fgiust $)
 */
public class HtmlAttributeMap extends HashMap
{

    /**
     * D1597A17A6.
     */
    private static final long serialVersionUID = 899149338534L;

    /**
     * Attribute value delimiter.
     */
    private static final char DELIMITER = '"';

    /**
     * character between name and value.
     */
    private static final char EQUALS = '=';

    /**
     * space before any attribute.
     */
    private static final char SPACE = ' ';

    /**
     * toString method: returns attributes in the format: attributename="attributevalue" attr2="attrValue2" ...
     * @return String representation of the HtmlAttributeMap
     */
    public String toString()
    {
        // fast exit when no attribute are present
        if (size() == 0)
        {
            return TagConstants.EMPTY_STRING;
        }

        // buffer extimated in number of attributes * 30
        StringBuffer buffer = new StringBuffer(size() * 30);

        // get the entrySet
        Set entrySet = entrySet();

        Iterator iterator = entrySet.iterator();

        // iterates on attributes
        while (iterator.hasNext())
        {
            Map.Entry entry = (Map.Entry) iterator.next();

            // append a new atribute
            buffer
                .append(SPACE)
                .append(entry.getKey())
                .append(EQUALS)
                .append(DELIMITER)
                .append(entry.getValue())
                .append(DELIMITER);
        }

        // return
        return buffer.toString();
    }
}