GenericFilterBean.java 文件源码

/**
 * Standard way of initializing this filter.
 * Map config parameters onto bean properties of this filter, and
 * invoke subclass initialization.
 * @param filterConfig the configuration for this filter
 * @throws ServletException if bean properties are invalid (or required
 * properties are missing), or if subclass initialization fails.
 * @see #initFilterBean
 */
@Override
public final void init(FilterConfig filterConfig) throws ServletException {
    Assert.notNull(filterConfig, "FilterConfig must not be null");
    if (logger.isDebugEnabled()) {
        logger.debug("Initializing filter '" + filterConfig.getFilterName() + "'");
    }

    this.filterConfig = filterConfig;

    // Set bean properties from init parameters.
    try {
        PropertyValues pvs = new FilterConfigPropertyValues(filterConfig, this.requiredProperties);
        BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(this);
        ResourceLoader resourceLoader = new ServletContextResourceLoader(filterConfig.getServletContext());
        bw.registerCustomEditor(Resource.class, new ResourceEditor(resourceLoader, this.environment));
        initBeanWrapper(bw);
        bw.setPropertyValues(pvs, true);
    }
    catch (BeansException ex) {
        String msg = "Failed to set bean properties on filter '" +
            filterConfig.getFilterName() + "': " + ex.getMessage();
        logger.error(msg, ex);
        throw new NestedServletException(msg, ex);
    }

    // Let subclasses do whatever initialization they like.
    initFilterBean();

    if (logger.isDebugEnabled()) {
        logger.debug("Filter '" + filterConfig.getFilterName() + "' configured successfully");
    }
}