Example usage for com.vaadin.server VaadinResponse setDateHeader

Introduction

In this page you can find the example usage for com.vaadin.server VaadinResponse setDateHeader.

Prototype

public void setDateHeader(String name, long timestamp);

Source Link

Document

Properly formats a timestamp as a date header.

Usage

From source file:com.haulmont.cuba.web.sys.CubaWebJarsHandler.java

License:Apache License

@Override
public boolean handleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response)
        throws IOException {
    String path = request.getPathInfo();

    if (StringUtils.isEmpty(path) || StringUtils.isNotEmpty(path) && !path.startsWith(VAADIN_WEBJARS_PREFIX)) {
        return false;
    }//from w w  w .ja va 2 s  .c  o  m

    log.trace("WebJar resource requested: {}", path.replace(VAADIN_WEBJARS_PREFIX, ""));

    String errorMessage = checkResourcePath(path);
    if (StringUtils.isNotEmpty(errorMessage)) {
        log.warn(errorMessage);
        response.sendError(HttpServletResponse.SC_FORBIDDEN, errorMessage);
        return false;
    }

    URL resourceUrl = getStaticResourceUrl(path);

    if (resourceUrl == null) {
        resourceUrl = getClassPathResourceUrl(path);
    }

    if (resourceUrl == null) {
        String msg = String.format("Requested WebJar resource is not found: %s", path);
        response.sendError(HttpServletResponse.SC_NOT_FOUND, msg);
        log.warn(msg);
        return false;
    }

    String resourceName = getResourceName(path);
    String mimeType = servletContext.getMimeType(resourceName);
    response.setContentType(mimeType != null ? mimeType : FileTypesHelper.DEFAULT_MIME_TYPE);

    String cacheControl = "public, max-age=0, must-revalidate";
    int resourceCacheTime = getCacheTime(resourceName);
    if (resourceCacheTime > 0) {
        cacheControl = "max-age=" + String.valueOf(resourceCacheTime);
    }
    response.setHeader("Cache-Control", cacheControl);
    response.setDateHeader("Expires", System.currentTimeMillis() + (resourceCacheTime * 1000));

    InputStream inputStream = null;
    try {
        URLConnection connection = resourceUrl.openConnection();
        long lastModifiedTime = connection.getLastModified();
        // Remove milliseconds to avoid comparison problems (milliseconds
        // are not returned by the browser in the "If-Modified-Since"
        // header).
        lastModifiedTime = lastModifiedTime - lastModifiedTime % 1000;
        response.setDateHeader("Last-Modified", lastModifiedTime);

        if (browserHasNewestVersion(request, lastModifiedTime)) {
            response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
            return true;
        }

        inputStream = connection.getInputStream();

        copy(inputStream, response.getOutputStream());

        return true;
    } finally {
        if (inputStream != null) {
            inputStream.close();
        }
    }
}

---