Merge pull request #4679 from jaikiran/qk-4627

Testcase to verify that the StaticHandler can handle requests with If-Modified-Since header without running into thread safety issues

extensions/resteasy/deployment/src/test/java/io/quarkus/resteasy/test/files/StaticFileWithResourcesTest.java

@@ -3,6 +3,18 @@
 import static org.hamcrest.CoreMatchers.containsString;
 
 import java.io.File;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
 
 import org.jboss.shrinkwrap.api.ShrinkWrap;
 import org.jboss.shrinkwrap.api.spec.JavaArchive;
@@ -39,4 +51,46 @@ public void test() {
                 .statusCode(200)
                 .body(containsString("Lorem"));
     }
+
+    /**
+     * Tests that multiple simultaneous requests to a static resource, with each request
+     * using the {@code If-Modified-Since} header, doesn't cause server side errors.
+     *
+     * @throws Exception
+     * @see <a href="https://github.com/quarkusio/quarkus/issues/4627"/>
+     */
+    @Test
+    public void testMultipleThreadedRequestWithIfModifiedSince() throws Exception {
+        // RFC1123 date formatter
+        final DateFormat dtf = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.ENGLISH);
+        dtf.setTimeZone(TimeZone.getTimeZone("GMT"));
+        // date in past, so that we always get a 200 response, instead of 304
+        final Date fiveMinInPast = new Date(System.currentTimeMillis() - (5 * 60 * 1000));
+        final String modifiedSinceHeader = dtf.format(fiveMinInPast);
+        final int numRequests = 10;
+        final ExecutorService executorService = Executors.newFixedThreadPool(numRequests);
+        try {
+            final List<Future<Void>> results = new ArrayList<>();
+            for (int i = 0; i < numRequests; i++) {
+                // issue the requests
+                results.add(executorService.submit(new Callable<Void>() {
+                    @Override
+                    public Void call() throws Exception {
+                        RestAssured.given().header("If-Modified-Since", modifiedSinceHeader)
+                                .get("/web/index.html")
+                                .then()
+                                .body(containsString("<h1>Hello</h1>"))
+                                .statusCode(200);
+                        return null;
+                    }
+                }));
+            }
+            // wait for completion
+            for (int i = 0; i < numRequests; i++) {
+                results.get(i).get(1, TimeUnit.MINUTES);
+            }
+        } finally {
+            executorService.shutdownNow();
+        }
+    }
 }