Limit request methods on the proxy endpoint (oncokb#1125)

src/main/java/org/mskcc/cbio/oncokb/web/rest/ApiProxy.java

@@ -18,6 +18,7 @@
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.RestTemplate;
@@ -63,7 +64,7 @@ public class ApiProxy {
 
     private String IP_HEADER = "X-FORWARDED-FOR";
 
-    @RequestMapping("/**")
+    @RequestMapping(path = "/**", method = {RequestMethod.GET, RequestMethod.POST, RequestMethod.HEAD})
     public ResponseEntity<String> proxy(@RequestBody(required = false) String body, HttpMethod method, HttpServletRequest request)
         throws URISyntaxException {
         URI uri = apiProxyService.prepareURI(request);