Portability to Java 6 support

This framework should be able to be binary compatible with Java 6 as
Netty does.
This merge request allows minor changes to be able to be compatible.

Also it upgrades dependencies and allows OPTION method (which was
missing).

pom.xml

@@ -62,14 +62,14 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <surefire.redirectTestOutputToFile>true</surefire.redirectTestOutputToFile>
 
-    <rs-api.version>2.0</rs-api.version>
-    <netty.version>4.1.16.Final</netty.version>
-    <slf4j.version>1.7.5</slf4j.version>
+    <rs-api.version>2.1.1</rs-api.version>
+    <netty.version>4.1.36.Final</netty.version>
+    <slf4j.version>1.7.26</slf4j.version>
     <findbugs.version>2.0.1</findbugs.version>
     <beanutils.version>1.8.3</beanutils.version>
-    <junit.version>4.11</junit.version>
-    <logback.version>1.0.9</logback.version>
-    <gson.version>2.2.4</gson.version>
+    <junit.version>4.12</junit.version>
+    <logback.version>1.2.3</logback.version>
+    <gson.version>2.8.5</gson.version>
   </properties>
 
   <dependencies>
@@ -135,10 +135,27 @@
       <version>${gson.version}</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+    	<groupId>io.cdap.http</groupId>
+    	<artifactId>netty-http</artifactId>
+    	<version>1.2.0</version>
+    </dependency>
   </dependencies>
 
   <build>
     <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>animal-sniffer-maven-plugin</artifactId>
+        <version>1.16</version>
+        <configuration>
+          <signature>
+            <groupId>org.codehaus.mojo.signature</groupId>
+            <artifactId>java16</artifactId>
+	    <version>1.0</version>
+          </signature>
+        </configuration>
+      </plugin>
       <!-- Compiler -->
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
@@ -174,7 +191,6 @@
           </execution>
         </executions>
       </plugin>
-
       <!-- Checkstyle -->
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>

src/main/java/io/cdap/http/AbstractHttpResponder.java

@@ -16,6 +16,7 @@
 
 package io.cdap.http;
 
+import io.cdap.http.internal.InternalUtil;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.handler.codec.http.DefaultHttpHeaders;
@@ -27,15 +28,13 @@
 import java.io.File;
 import java.io.IOException;
 import java.nio.ByteBuffer;
-import java.nio.charset.StandardCharsets;
 
 /**
  * Base implementation of {@link HttpResponder} to simplify child implementations.
  */
 public abstract class AbstractHttpResponder implements HttpResponder {
 
   protected static final String OCTET_STREAM_TYPE = "application/octet-stream";
-
   @Override
   public void sendJson(HttpResponseStatus status, String jsonString) {
     sendString(status, jsonString, new DefaultHttpHeaders().add(HttpHeaderNames.CONTENT_TYPE.toString(),
@@ -53,7 +52,7 @@ public void sendString(HttpResponseStatus status, String data, HttpHeaders heade
       sendStatus(status, headers);
       return;
     }
-    ByteBuf buffer = Unpooled.wrappedBuffer(StandardCharsets.UTF_8.encode(data));
+    ByteBuf buffer = Unpooled.wrappedBuffer(InternalUtil.UTF_8.encode(data));
     sendContent(status, buffer, addContentTypeIfMissing(new DefaultHttpHeaders().add(headers),
                                                         "text/plain; charset=utf-8"));
   }
@@ -80,7 +79,7 @@ public void sendBytes(HttpResponseStatus status, ByteBuffer buffer, HttpHeaders
   }
 
   @Override
-  public void sendFile(File file) throws IOException {
+  public void sendFile(File file) throws Throwable {
     sendFile(file, EmptyHttpHeaders.INSTANCE);
   }
 

src/main/java/io/cdap/http/HttpResponder.java

@@ -124,8 +124,9 @@ public interface HttpResponder {
    *
    * @param file The file to send
    * @throws IOException if failed to open and read the file
+   * @throws Throwable 
    */
-  void sendFile(File file) throws IOException;
+  void sendFile(File file) throws IOException, Throwable;
 
   /**
    * Sends a file content back to client with response status 200. Default content type is "application/octet-stream",
@@ -134,8 +135,9 @@ public interface HttpResponder {
    * @param file The file to send
    * @param headers additional headers to send with the response.
    * @throws IOException if failed to open and read the file
+   * @throws Throwable 
    */
-  void sendFile(File file, HttpHeaders headers) throws IOException;
+  void sendFile(File file, HttpHeaders headers) throws IOException, Throwable;
 
   /**
    * Sends response back to client. The response body is produced by the given {@link BodyProducer}. This method

src/main/java/io/cdap/http/NettyHttpService.java

@@ -129,8 +129,8 @@ private NettyHttpService(String serviceName,
     this.workerThreadPoolSize = workerThreadPoolSize;
     this.execThreadPoolSize = execThreadPoolSize;
     this.execThreadKeepAliveSecs = execThreadKeepAliveSecs;
-    this.channelConfigs = new HashMap<>(channelConfigs);
-    this.childChannelConfigs = new HashMap<>(childChannelConfigs);
+    this.channelConfigs = new HashMap<ChannelOption, Object>(channelConfigs);
+    this.childChannelConfigs = new HashMap<ChannelOption, Object>(childChannelConfigs);
     this.rejectedExecutionHandler = rejectedExecutionHandler;
     this.resourceHandler = new HttpResourceHandler(httpHandlers, handlerHooks, urlRewriter, exceptionHandler);
     this.handlerContext = new BasicHandlerContext(this.resourceHandler);
@@ -152,10 +152,9 @@ public static Builder builder(String serviceName) {
 
   /**
    * Starts the HTTP service.
-   *
-   * @throws Exception if the service failed to started
+ * @throws Throwable 
    */
-  public synchronized void start() throws Exception {
+  public synchronized void start() throws Throwable {
     if (state == State.RUNNING) {
       LOG.debug("Ignore start() call on HTTP service {} since it has already been started.", serviceName);
       return;
@@ -193,7 +192,6 @@ public synchronized void start() throws Exception {
           shutdownExecutorGroups(0, 5, TimeUnit.SECONDS, eventExecutorGroup);
         }
       } catch (Throwable t2) {
-        t.addSuppressed(t2);
       }
       state = State.FAILED;
       throw t;
@@ -224,10 +222,9 @@ public boolean isSSLEnabled() {
   /**
    * Stops the HTTP service gracefully and release all resources. Same as calling {@link #stop(long, long, TimeUnit)}
    * with {@code 0} second quiet period and {@code 5} seconds timeout.
-   *
-   * @throws Exception if there is exception raised during shutdown.
+ * @throws Throwable 
    */
-  public void stop() throws Exception {
+  public void stop() throws Throwable {
     stop(0, 5, TimeUnit.SECONDS);
   }
 
@@ -239,9 +236,9 @@ public void stop() throws Exception {
    *                    {@linkplain EventExecutorGroup#shutdown()}
    *                    regardless if a task was submitted during the quiet period
    * @param unit        the unit of {@code quietPeriod} and {@code timeout}
-   * @throws Exception if there is exception raised during shutdown.
+ * @throws Throwable 
    */
-  public synchronized void stop(long quietPeriod, long timeout, TimeUnit unit) throws Exception {
+  public synchronized void stop(long quietPeriod, long timeout, TimeUnit unit) throws Throwable {
     if (state == State.STOPPED) {
       LOG.debug("Ignore stop() call on HTTP service {} since it has already been stopped.", serviceName);
       return;
@@ -377,7 +374,7 @@ protected void initChannel(SocketChannel ch) throws Exception {
    */
   private void shutdownExecutorGroups(long quietPeriod, long timeout, TimeUnit unit, EventExecutorGroup...groups) {
     Exception ex = null;
-    List<Future<?>> futures = new ArrayList<>();
+    List<Future<?>> futures = new ArrayList<Future<?>>();
     for (EventExecutorGroup group : groups) {
       if (group == null) {
         continue;
@@ -391,8 +388,6 @@ private void shutdownExecutorGroups(long quietPeriod, long timeout, TimeUnit uni
       } catch (Exception e) {
         if (ex == null) {
           ex = e;
-        } else {
-          ex.addSuppressed(e);
         }
       }
     }
@@ -449,8 +444,8 @@ protected Builder(String serviceName) {
       rejectedExecutionHandler = DEFAULT_REJECTED_EXECUTION_HANDLER;
       httpChunkLimit = DEFAULT_HTTP_CHUNK_LIMIT;
       port = 0;
-      channelConfigs = new HashMap<>();
-      childChannelConfigs = new HashMap<>();
+      channelConfigs = new HashMap<ChannelOption, Object>();
+      childChannelConfigs = new HashMap<ChannelOption, Object>();
       channelConfigs.put(ChannelOption.SO_BACKLOG, DEFAULT_CONNECTION_BACKLOG);
       sslHandlerFactory = null;
       exceptionHandler = new ExceptionHandler();

src/main/java/io/cdap/http/SSLHandlerFactory.java

@@ -70,10 +70,16 @@ public SSLHandlerFactory(SslContext sslContext) {
   }
 
   private static KeyStore getKeyStore(File keyStore, String keyStorePassword) throws Exception {
-    try (InputStream is = new FileInputStream(keyStore)) {
+    InputStream is = null;
+    try {
+      is = new FileInputStream(keyStore);
       KeyStore ks = KeyStore.getInstance("JKS");
       ks.load(is, keyStorePassword.toCharArray());
       return ks;
+    } finally {
+      if (is != null) {
+        is.close();
+      }
     }
   }
 

src/main/java/io/cdap/http/internal/BasicHttpResponder.java

@@ -50,7 +50,6 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.nio.charset.StandardCharsets;
 import java.util.concurrent.atomic.AtomicBoolean;
 import javax.annotation.Nullable;
 
@@ -105,7 +104,7 @@ public void sendContent(HttpResponseStatus status, ByteBuf content, HttpHeaders
   }
 
   @Override
-  public void sendFile(File file, HttpHeaders headers) throws IOException {
+  public void sendFile(File file, HttpHeaders headers) throws Throwable {
     HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
     addContentTypeIfMissing(response.headers().add(headers), OCTET_STREAM_TYPE);
 
@@ -136,7 +135,6 @@ public void sendFile(File file, HttpHeaders headers) throws IOException {
       try {
         raf.close();
       } catch (IOException ex) {
-        t.addSuppressed(ex);
       }
       throw t;
     }
@@ -152,7 +150,7 @@ public void sendContent(HttpResponseStatus status, final BodyProducer bodyProduc
       // Response with error and close the connection
       sendContent(
         HttpResponseStatus.INTERNAL_SERVER_ERROR,
-        Unpooled.copiedBuffer("Failed to determined content length. Cause: " + t.getMessage(), StandardCharsets.UTF_8),
+        Unpooled.copiedBuffer("Failed to determined content length. Cause: " + t.getMessage(), InternalUtil.UTF_8),
         new DefaultHttpHeaders()
           .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE)
           .set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=utf-8"));
@@ -197,7 +195,7 @@ boolean isResponded() {
   private ChannelFutureListener createBodyProducerCompletionListener(final BodyProducer bodyProducer) {
     return new ChannelFutureListener() {
       @Override
-      public void operationComplete(ChannelFuture future) throws Exception {
+      public void operationComplete(ChannelFuture future) {
         if (!future.isSuccess()) {
           callBodyProducerHandleError(bodyProducer, future.cause());
           channel.close();

src/main/java/io/cdap/http/internal/HandlerException.java

@@ -24,8 +24,6 @@
 import io.netty.handler.codec.http.HttpUtil;
 import io.netty.handler.codec.http.HttpVersion;
 
-import java.nio.charset.StandardCharsets;
-
 /**
  *Creating Http Response for Exception messages.
  */
@@ -48,7 +46,7 @@ final class HandlerException extends Exception {
 
   HttpResponse createFailureResponse() {
     FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, failureStatus,
-                                                            Unpooled.copiedBuffer(message, StandardCharsets.UTF_8));
+                                                            Unpooled.copiedBuffer(message, InternalUtil.UTF_8));
     HttpUtil.setContentLength(response, response.content().readableBytes());
     return response;
   }

src/main/java/io/cdap/http/internal/HttpResourceHandler.java

@@ -44,6 +44,7 @@
 import javax.annotation.Nullable;
 import javax.ws.rs.DELETE;
 import javax.ws.rs.GET;
+import javax.ws.rs.OPTIONS;
 import javax.ws.rs.POST;
 import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
@@ -135,7 +136,7 @@ public HttpResourceHandler(Iterable<? extends HttpHandler> handlers, Iterable<?
    * @return String representation of HttpMethod from annotations or emptyString as a default.
    */
   private Set<HttpMethod> getHttpMethods(Method method) {
-    Set<HttpMethod> httpMethods = new HashSet<>();
+    Set<HttpMethod> httpMethods = new HashSet<HttpMethod>();
 
     if (method.isAnnotationPresent(GET.class)) {
       httpMethods.add(HttpMethod.GET);
@@ -149,6 +150,9 @@ private Set<HttpMethod> getHttpMethods(Method method) {
     if (method.isAnnotationPresent(DELETE.class)) {
       httpMethods.add(HttpMethod.DELETE);
     }
+    if (method.isAnnotationPresent(OPTIONS.class)) {
+      httpMethods.add(HttpMethod.OPTIONS);
+    }
 
     return Collections.unmodifiableSet(httpMethods);
   }
@@ -310,7 +314,8 @@ public HttpMethodInfo getDestinationMethod(HttpRequest request, HttpResponder re
 
     LOG.trace("Routable destinations for request {}: {}", requestUri, routableDestinations);
     Iterable<String> requestUriParts = splitAndOmitEmpty(requestUri, '/');
-    List<PatternPathRouterWithGroups.RoutableDestination<HttpResourceModel>> matchedDestinations = new ArrayList<>();
+    List<PatternPathRouterWithGroups.RoutableDestination<HttpResourceModel>> matchedDestinations =
+            new ArrayList<PatternPathRouterWithGroups.RoutableDestination<HttpResourceModel>>();
     long maxScore = 0;
 
     for (PatternPathRouterWithGroups.RoutableDestination<HttpResourceModel> destination : routableDestinations) {
@@ -390,7 +395,7 @@ public void destroy(HandlerContext context) {
   }
 
   private static <T> List<T> copyOf(Iterable<? extends T> iterable) {
-    List<T> list = new ArrayList<>();
+    List<T> list = new ArrayList<T>();
     for (T item : iterable) {
       list.add(item);
     }

src/main/java/io/cdap/http/internal/HttpResourceModel.java

@@ -48,7 +48,8 @@
 public final class HttpResourceModel {
 
   private static final Set<Class<? extends Annotation>> SUPPORTED_PARAM_ANNOTATIONS =
-    Collections.unmodifiableSet(new HashSet<>(Arrays.asList(PathParam.class, QueryParam.class, HeaderParam.class)));
+    Collections.unmodifiableSet(new HashSet<Class<? extends Annotation>>
+            (Arrays.asList(PathParam.class, QueryParam.class, HeaderParam.class)));
 
   private final Set<HttpMethod> httpMethods;
   private final String path;
@@ -211,13 +212,15 @@ private List<Map<Class<? extends Annotation>, ParameterInfo<?>>> createParameter
       return Collections.emptyList();
     }
 
-    List<Map<Class<? extends Annotation>, ParameterInfo<?>>> result = new ArrayList<>();
+    List<Map<Class<? extends Annotation>, ParameterInfo<?>>> result =
+            new ArrayList<Map<Class<? extends Annotation>, ParameterInfo<?>>>();
     Type[] parameterTypes = method.getGenericParameterTypes();
     Annotation[][] parameterAnnotations = method.getParameterAnnotations();
 
     for (int i = 2; i < parameterAnnotations.length; i++) {
       Annotation[] annotations = parameterAnnotations[i];
-      Map<Class<? extends Annotation>, ParameterInfo<?>> paramAnnotations = new IdentityHashMap<>();
+      Map<Class<? extends Annotation>, ParameterInfo<?>> paramAnnotations =
+              new IdentityHashMap<Class<? extends Annotation>, ParameterInfo<?>>();
 
       for (Annotation annotation : annotations) {
         Class<? extends Annotation> annotationType = annotation.annotationType();
@@ -266,7 +269,7 @@ private static final class ParameterInfo<T> {
     private final Converter<T, Object> converter;
 
     static <V> ParameterInfo<V> create(Annotation annotation, @Nullable Converter<V, Object> converter) {
-      return new ParameterInfo<>(annotation, converter);
+      return new ParameterInfo<V>(annotation, converter);
     }
 
     private ParameterInfo(Annotation annotation, @Nullable Converter<T, Object> converter) {