title: Setting X-Frame-Options header without changing java
body: <p>I have a black box application that runs on old obsolete Jetty 7. However, it has been working well since we installed it in 2014, and I need it to continue running. I have been asked to add an X-Frame-Options header to the interface, and every time I try to do this by changing Java I get class incompatibility errors. I can, however, make any changes I like to the JSP files, to web.xml, or to the Jetty configuration files in jetty/etc, but so far I have not found a change that works. I tried adding </p>
  
  <p>&lt;* response.addHeader(“X-FRAME-OPTIONS”, “DENY”); *></p>
  
  <p>to various JSP files but it doesn't seem to help. Does anyone have any ideas?</p>