Java Code Examples for org.apache.catalina.WebResource#getLastModified()

/**
 * Check if the if-modified-since condition is satisfied.
 *
 * @param request   The servlet request we are processing
 * @param response  The servlet response we are creating
 * @param resource  The resource
 * @return <code>true</code> if the resource meets the specified condition,
 *  and <code>false</code> if the condition is not satisfied, in which case
 *  request processing is stopped
 */
protected boolean checkIfModifiedSince(HttpServletRequest request,
        HttpServletResponse response, WebResource resource) {
    try {
        long headerValue = request.getDateHeader("If-Modified-Since");
        long lastModified = resource.getLastModified();
        if (headerValue != -1) {

            // If an If-None-Match header has been specified, if modified since
            // is ignored.
            if ((request.getHeader("If-None-Match") == null)
                && (lastModified < headerValue + 1000)) {
                // The entity has not been modified since the date
                // specified by the client. This is not an error case.
                response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
                response.setHeader("ETag", resource.getETag());

                return false;
            }
        }
    } catch (IllegalArgumentException illegalArgument) {
        return true;
    }
    return true;
}
 

/**
 * Check if the if-unmodified-since condition is satisfied.
 *
 * @param request   The servlet request we are processing
 * @param response  The servlet response we are creating
 * @param resource  The resource
 * @return <code>true</code> if the resource meets the specified condition,
 *  and <code>false</code> if the condition is not satisfied, in which case
 *  request processing is stopped
 * @throws IOException an IO error occurred
 */
protected boolean checkIfUnmodifiedSince(HttpServletRequest request,
        HttpServletResponse response, WebResource resource)
        throws IOException {
    try {
        long lastModified = resource.getLastModified();
        long headerValue = request.getDateHeader("If-Unmodified-Since");
        if (headerValue != -1) {
            if ( lastModified >= (headerValue + 1000)) {
                // The entity has not been modified since the date
                // specified by the client. This is not an error case.
                response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
                return false;
            }
        }
    } catch(IllegalArgumentException illegalArgument) {
        return true;
    }
    return true;
}
 

private void trackLastModified(String path, WebResource resource) {
    if (resourceEntries.containsKey(path)) {
        return;
    }
    ResourceEntry entry = new ResourceEntry();
    entry.lastModified = resource.getLastModified();
    synchronized(resourceEntries) {
        if (!resourceEntries.containsKey(path)) {
            resourceEntries.put(path, entry);
        }
    }
}
 

protected boolean validateResource(boolean useClassLoaderResources) {
    // It is possible that some resources will only be visible for a given
    // value of useClassLoaderResources. Therefore, if the lookup is made
    // with a different value of useClassLoaderResources than was used when
    // creating the cache entry, invalidate the entry. This should have
    // minimal performance impact as it would be unusual for a resource to
    // be looked up both as a static resource and as a class loader
    // resource.
    if (usesClassLoaderResources != useClassLoaderResources) {
        return false;
    }

    long now = System.currentTimeMillis();

    if (webResource == null) {
        synchronized (this) {
            if (webResource == null) {
                webResource = root.getResourceInternal(
                        webAppPath, useClassLoaderResources);
                getLastModified();
                getContentLength();
                nextCheck = ttl + now;
                // exists() is a relatively expensive check for a file so
                // use the fact that we know if it exists at this point
                if (webResource instanceof EmptyResource) {
                    cachedExists = Boolean.FALSE;
                } else {
                    cachedExists = Boolean.TRUE;
                }
                return true;
            }
        }
    }

    if (now < nextCheck) {
        return true;
    }

    // Assume resources inside WARs will not change
    if (!root.isPackedWarFile()) {
        WebResource webResourceInternal = root.getResourceInternal(
                webAppPath, useClassLoaderResources);
        if (!webResource.exists() && webResourceInternal.exists()) {
            return false;
        }

        // If modified date or length change - resource has changed / been
        // removed etc.
        if (webResource.getLastModified() != getLastModified() ||
                webResource.getContentLength() != getContentLength()) {
            return false;
        }

        // Has a resource been inserted / removed in a different resource set
        if (webResource.getLastModified() != webResourceInternal.getLastModified() ||
                webResource.getContentLength() != webResourceInternal.getContentLength()) {
            return false;
        }
    }

    nextCheck = ttl + now;
    return true;
}