Example usage for com.vaadin.server VaadinRequest getDateHeader

Introduction

In this page you can find the example usage for com.vaadin.server VaadinRequest getDateHeader.

Prototype

public long getDateHeader(String name);

Source Link

Document

Returns the value of the specified request header as a long value that represents a Date object.

Usage

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

License:Apache License

protected boolean browserHasNewestVersion(VaadinRequest request, long resourceLastModifiedTimestamp) {
    if (resourceLastModifiedTimestamp < 1) {
        // We do not know when it was modified so the browser cannot have an
        // up-to-date version
        return false;
    }//from  w w w. j  a  v  a2  s  .c o m
    /*
     * The browser can request the resource conditionally using an
     * If-Modified-Since header. Check this against the last modification
     * time.
     */
    try {
        // If-Modified-Since represents the timestamp of the version cached
        // in the browser
        long headerIfModifiedSince = request.getDateHeader("If-Modified-Since");

        if (headerIfModifiedSince >= resourceLastModifiedTimestamp) {
            // Browser has this an up-to-date version of the resource
            return true;
        }
    } catch (Exception e) {
        // Failed to parse header. Fail silently - the browser does not have
        // an up-to-date version in its cache.
    }
    return false;
}

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