HeaderTag.java 文件源码

/**
 * Expose a single header value.
 * @throws JspException
 * @since Struts 1.2
 */
protected void handleSingleHeader() throws JspException {
    String value =
        ((HttpServletRequest) pageContext.getRequest()).getHeader(name);

    if ((value == null) && (this.value != null)) {
        value = this.value;
    }

    if (value == null) {
        JspException e =
            new JspException(messages.getMessage("header.get", name));
        TagUtils.getInstance().saveException(pageContext, e);
        throw e;
    }

    pageContext.setAttribute(id, value);
}