如何使用Wicket 7使图像可缓存？

Question

I have png files both in the file system and in a database. So I tried to use

ByteArrayResource

which displayed the image only once. A browser refresh only showed an image placeholder. The image url had a parameter appended:

&antiCache=123456789

So ByteArrayResource looks to me like it can only be used once and has to be reloaded even when the page only gets refresehd. Next I tried

PackageResource

which displayed the image in the browser (even after a refresh) but also rendered the "antiCache" parameter. This happened even after explicitly calling

setCachingEnable( true );

Also "PackageResource" cannot use my png data from the database.

Answer 1

The antiCache parameter is added only in Ajax responses. If you add the image in the Ajax response ( https://github.com/apache/wicket/blob/70606d73e9165d37c1d8b7c7820279fb4be18770/wicket-core/src/main/java/org/apache/wicket/markup/html/image/Image.java#L543 ) then Wicket assumes that it has to be repainted, so it modifies the url. You can override this method and suppress this behavior.