帮忙看下这种程序，如何能实现下拉菜单的方式！

import java.text.ParseException;

import javax.servlet.http.HttpServletRequest;

import org.jbpm.workflow.delegation.*;

/**

* @author Tom Baeyens

*/

public class TextInput extends AbstractConfigurable implements HtmlFormatter {

public String objectToHtml( Object value, String parameterName, HttpServletRequest request) {

String html = null;

String size = "10";

if ( getConfiguration().containsKey("size") ) {

size = (String) getConfiguration().get("size");

}

String text = "";

if ( value != null ) text = (String) value;

html = "<input type=text size=" + size + " name=\"" + parameterName + "\" value=\"" + text + "\">";

return html;

}

public Object parseHttpParameter( String text, HttpServletRequest request ) throws ParseException {

return text;

}

}