MINOR: Remove 'disable caching' workaround for Java 8 in connect (#18823

)

Reviewers: Chia-Ping Tsai <[email protected]>, Greg Harris <[email protected]>

tools/src/test/java/org/apache/kafka/tools/ConnectPluginPathTest.java

@@ -489,14 +489,12 @@ private static PluginLocation setupLocation(Path path, PluginLocationType type,
                     outputJar.getParent().toFile().mkdirs();
                     Files.copy(jarPath, outputJar, StandardCopyOption.REPLACE_EXISTING);
                     outputJar.toUri().toURL().openConnection().setDefaultUseCaches(false);
-                    disableCaching(outputJar);
                     return new PluginLocation(outputJar);
                 }
                 case MULTI_JAR: {
                     Path outputJar = path.resolve(jarPath.getFileName());
                     outputJar.getParent().toFile().mkdirs();
                     Files.copy(jarPath, outputJar, StandardCopyOption.REPLACE_EXISTING);
-                    disableCaching(outputJar);
                     return new PluginLocation(path);
                 }
                 default:
@@ -507,15 +505,6 @@ private static PluginLocation setupLocation(Path path, PluginLocationType type,
         }
     }
 
-    private static void disableCaching(Path path) throws IOException {
-        // This function is a workaround for a Java 8 caching bug. When Java 8 support is dropped it may be removed.
-        // This test runs the sync-manifests command, and _without stopping the jvm_ executes a list command.
-        // Under normal use, the sync-manifests command is followed immediately by a JVM shutdown, clearing caches.
-        // The Java 8 ServiceLoader does not disable the URLConnection caching, so doesn't read some previous writes.
-        // Java 9+ ServiceLoaders disable the URLConnection caching, so don't need this patch (it becomes a no-op)
-        path.toUri().toURL().openConnection().setDefaultUseCaches(false);
-    }
-
     private static class PluginPathElement {
         private final Path root;
         private final List<PluginLocation> locations;