MailerCustomTag

package es.sinjava.labs;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;

public class MailerTag extends TagSupport {

    private static final String CONTENT_MAILER = "contentMailer";
    private String styleClass;
    private String messageClass;
    private String cols;
    private String rows;

    public String getCols() {
        return cols;
    }

    public void setCols(String cols) {
        this.cols = cols;
    }

    @Override
    public int doStartTag() throws JspException {
        HttpServletRequest request = (HttpServletRequest) pageContext
                .getRequest();
        StringBuffer sb = null;
        String texto = request.getParameter(CONTENT_MAILER);
        if (texto != null) {

            // Creamos el correo
            MailSender mailSender = new MailSender();
            mailSender.setText(texto);

            // lo lanzamos en segundo plano
            Thread segundoPlano = new Thread(mailSender);
            segundoPlano.start();

            // Escribimos la salida
            sb = new StringBuffer("<span ");
            prepareAttribute(sb, "class", getMessageClass());
            sb.append(" > Su Solicitud ha sido registrada ");
            sb.append(" </span>");
        } else {
            sb = new StringBuffer("<textarea ");
            // HttpServletResponse resp = (HttpServletResponse) pageContext
            // .getResponse();
            prepareAttribute(sb, "id", getId());
            prepareAttribute(sb, "name", CONTENT_MAILER);
            prepareAttribute(sb, "class", getStyleClass());
            prepareAttribute(sb, "cols", getCols());
            prepareAttribute(sb, "rows", getRows());
            sb.append(" > default value");
            sb.append(" </textarea>");
        }
        JspWriter out = pageContext.getOut();
        try {
            out.print(sb.toString());
        } catch (java.io.IOException e) {
            throw new JspException("IOException while writing to client: " + e);
        }
        return SKIP_BODY;
    }

    @Override
    public int doEndTag() throws JspException {
        return EVAL_PAGE;
    }

    private void prepareAttribute(StringBuffer sb, String name, String value) {
        if ((value != null) && (value.trim().length() > 0)) {
            sb.append(" ");
            sb.append(name);
            sb.append("=\"");
            sb.append(value.trim());
            sb.append("\"");
        }
    }

    public String getStyleClass() {
        return styleClass;
    }

    public void setStyleClass(String styleClass) {
        this.styleClass = styleClass;
    }

    public String getRows() {
        return rows;
    }

    public void setRows(String rows) {
        this.rows = rows;
    }

    public String getMessageClass() {
        return messageClass;
    }

    public void setMessageClass(String messageClass) {
        this.messageClass = messageClass;
    }

}

class MailSender implements Runnable {

    private String text;

    public void run() {
        Mailer mailer = new Mailer(text);
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }
}