wro4j-core/src/main/java/ro/isdc/wro/model/resource/processor/impl/css/CssUrlRewritingProcessor.java
@Override
  protected String replaceImageUrl(final String cssUri, final String imageUrl) {
    //Can be null when using standalone context.
    final String contextPath = context.getRequest() != null ? context.getRequest().getContextPath() : null;
    final RewriterContext rewriterContext = new RewriterContext().setAggregatedFolderPath(
        context.getAggregatedFolderPath()).setProxyPrefix(getUrlPrefix()).setContextPath(contextPath);

    return new ImageUrlRewriter(rewriterContext).rewrite(cssUri, imageUrl);
  }
@Override
  protected String replaceImageUrl(final String cssUri, final String imageUrl) {
    //Can be null when using standalone context.
    final String contextPath = context.getRequest() != null ? context.getRequest().getContextPath() : null;
    final RewriterContext rewriterContext = new RewriterContext().setAggregatedFolderPath(
        context.getAggregatedFolderPath()).setProxyPrefix(getUrlPrefix()).setContextPath(contextPath);

    return new ImageUrlRewriter(rewriterContext).rewrite(cssUri, imageUrl);
  }
Replace provided url with the new url if needed.

@param cssUri
Uri of the parsed css.
@param imageUrl
to replace.
@return replaced url.