Clean up the examples

Motivation:

The examples have not been updated since long time ago, showing various
issues fixed in this commit.

Modifications:

- Overall simplification to reduce LoC
  - Use system properties to get options instead of parsing args.
  - Minimize option validation
  - Just use System.out/err instead of Logger
  - Do not pass config as parameters - just access it directly
  - Move the main logic to main(String[]) instead of creating a new
    instance meaninglessly
    - Update netty-build-21 to make checkstyle not complain
  - Remove 'throws Exception' clause if possible
- Line wrap at 120 (previously at 80)
- Add an option to enable SSL for most examples
- Use ChannelFuture.sync() instead of await()
- Use System.out for the actual result. Use System.err otherwise.
- Delete examples that are not very useful:
  - applet
  - websocket/html5
  - websocketx/sslserver
  - localecho/multithreaded
- Add run-example.sh which simplifies launching an example from command
  line
- Rewrite FileServer example

Result:

Shorter and simpler examples.  A user can focus more on what it actually
does than miscellaneous stuff.  A user can launch an example very
easily.

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksAuthRequestDecoder.java

@@ -27,11 +27,6 @@
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
 public class SocksAuthRequestDecoder extends ReplayingDecoder<SocksAuthRequestDecoder.State> {
-    private static final String name = "SOCKS_AUTH_REQUEST_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private SocksSubnegotiationVersion version;
     private int fieldLength;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksAuthResponseDecoder.java

@@ -26,11 +26,6 @@
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
 public class SocksAuthResponseDecoder extends ReplayingDecoder<SocksAuthResponseDecoder.State> {
-    private static final String name = "SOCKS_AUTH_RESPONSE_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private SocksSubnegotiationVersion version;
     private SocksAuthStatus authStatus;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksCmdRequestDecoder.java

@@ -27,11 +27,6 @@
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
 public class SocksCmdRequestDecoder extends ReplayingDecoder<SocksCmdRequestDecoder.State> {
-    private static final String name = "SOCKS_CMD_REQUEST_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private SocksProtocolVersion version;
     private int fieldLength;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksCmdResponseDecoder.java

@@ -27,11 +27,6 @@
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
 public class SocksCmdResponseDecoder extends ReplayingDecoder<SocksCmdResponseDecoder.State> {
-    private static final String name = "SOCKS_CMD_RESPONSE_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private SocksProtocolVersion version;
     private int fieldLength;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksInitRequestDecoder.java

@@ -27,11 +27,6 @@
  * Before returning SocksRequest decoder removes itself from pipeline.
  */
 public class SocksInitRequestDecoder extends ReplayingDecoder<SocksInitRequestDecoder.State> {
-    private static final String name = "SOCKS_INIT_REQUEST_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private final List<SocksAuthScheme> authSchemes = new ArrayList<SocksAuthScheme>();
     private SocksProtocolVersion version;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksInitResponseDecoder.java

@@ -26,11 +26,6 @@
  * Before returning SocksResponse decoder removes itself from pipeline.
  */
 public class SocksInitResponseDecoder extends ReplayingDecoder<SocksInitResponseDecoder.State> {
-    private static final String name = "SOCKS_INIT_RESPONSE_DECODER";
-
-    public static String getName() {
-        return name;
-    }
 
     private SocksProtocolVersion version;
     private SocksAuthScheme authScheme;

codec-socks/src/main/java/io/netty/handler/codec/socks/SocksMessageEncoder.java

@@ -28,12 +28,6 @@
  */
 @ChannelHandler.Sharable
 public class SocksMessageEncoder extends MessageToByteEncoder<SocksMessage> {
-    private static final String name = "SOCKS_MESSAGE_ENCODER";
-
-    public static String getName() {
-        return name;
-    }
-
     @Override
     protected void encode(ChannelHandlerContext ctx, SocksMessage msg, ByteBuf out) throws Exception {
         msg.encodeAsByteBuf(out);

example/src/main/java/io/netty/example/discard/DiscardClient.java

@@ -17,62 +17,57 @@
 
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 
 /**
  * Keeps sending random data to the specified address.
  */
-public class DiscardClient {
+public final class DiscardClient {
 
-    private final String host;
-    private final int port;
-    private final int firstMessageSize;
+    static final boolean SSL = System.getProperty("ssl") != null;
+    static final String HOST = System.getProperty("host", "127.0.0.1");
+    static final int PORT = Integer.parseInt(System.getProperty("port", "8009"));
+    static final int SIZE = Integer.parseInt(System.getProperty("size", "256"));
 
-    public DiscardClient(String host, int port, int firstMessageSize) {
-        this.host = host;
-        this.port = port;
-        this.firstMessageSize = firstMessageSize;
-    }
+    public static void main(String[] args) throws Exception {
+        // Configure SSL.
+        final SslContext sslCtx;
+        if (SSL) {
+            sslCtx = SslContext.newClientContext(InsecureTrustManagerFactory.INSTANCE);
+        } else {
+            sslCtx = null;
+        }
 
-    public void run() throws Exception {
         EventLoopGroup group = new NioEventLoopGroup();
         try {
             Bootstrap b = new Bootstrap();
             b.group(group)
              .channel(NioSocketChannel.class)
-             .handler(new DiscardClientHandler(firstMessageSize));
+             .handler(new ChannelInitializer<SocketChannel>() {
+                 @Override
+                 protected void initChannel(SocketChannel ch) throws Exception {
+                     ChannelPipeline p = ch.pipeline();
+                     if (sslCtx != null) {
+                         p.addLast(sslCtx.newHandler(ch.alloc(), HOST, PORT));
+                     }
+                     p.addLast(new DiscardClientHandler());
+                 }
+             });
 
             // Make the connection attempt.
-            ChannelFuture f = b.connect(host, port).sync();
+            ChannelFuture f = b.connect(HOST, PORT).sync();
 
             // Wait until the connection is closed.
             f.channel().closeFuture().sync();
         } finally {
             group.shutdownGracefully();
         }
     }
-
-    public static void main(String[] args) throws Exception {
-        // Print usage if no argument is specified.
-        if (args.length < 2 || args.length > 3) {
-            System.err.println(
-                    "Usage: " + DiscardClient.class.getSimpleName() +
-                    " <host> <port> [<first message size>]");
-            return;
-        }
-
-        // Parse options.
-        final String host = args[0];
-        final int port = Integer.parseInt(args[1]);
-        final int firstMessageSize;
-        if (args.length == 3) {
-            firstMessageSize = Integer.parseInt(args[2]);
-        } else {
-            firstMessageSize = 256;
-        }
-
-        new DiscardClient(host, port, firstMessageSize).run();
-    }
 }

example/src/main/java/io/netty/example/discard/DiscardClientHandler.java

@@ -21,59 +21,39 @@
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
 
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
 /**
  * Handles a client-side channel.
  */
 public class DiscardClientHandler extends SimpleChannelInboundHandler<Object> {
 
-    private static final Logger logger = Logger.getLogger(
-            DiscardClientHandler.class.getName());
-
-    private final int messageSize;
     private ByteBuf content;
     private ChannelHandlerContext ctx;
 
-    public DiscardClientHandler(int messageSize) {
-        if (messageSize <= 0) {
-            throw new IllegalArgumentException(
-                    "messageSize: " + messageSize);
-        }
-        this.messageSize = messageSize;
-    }
-
     @Override
-    public void channelActive(ChannelHandlerContext ctx)
-            throws Exception {
+    public void channelActive(ChannelHandlerContext ctx) {
         this.ctx = ctx;
 
         // Initialize the message.
-        content = ctx.alloc().directBuffer(messageSize).writeZero(messageSize);
+        content = ctx.alloc().directBuffer(DiscardClient.SIZE).writeZero(DiscardClient.SIZE);
 
         // Send the initial messages.
         generateTraffic();
     }
 
     @Override
-    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
+    public void channelInactive(ChannelHandlerContext ctx) {
         content.release();
     }
 
     @Override
-    public void messageReceived(ChannelHandlerContext ctx, Object msg) throws Exception {
+    public void messageReceived(ChannelHandlerContext ctx, Object msg) {
         // Server is supposed to send nothing, but if it sends something, discard it.
     }
 
     @Override
-    public void exceptionCaught(ChannelHandlerContext ctx,
-            Throwable cause) throws Exception {
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
         // Close the connection when an exception is raised.
-        logger.log(
-                Level.WARNING,
-                "Unexpected exception from downstream.",
-                cause);
+        cause.printStackTrace();
         ctx.close();
     }
 
@@ -87,9 +67,12 @@ private void generateTraffic() {
 
     private final ChannelFutureListener trafficGenerator = new ChannelFutureListener() {
         @Override
-        public void operationComplete(ChannelFuture future) throws Exception {
+        public void operationComplete(ChannelFuture future) {
             if (future.isSuccess()) {
                 generateTraffic();
+            } else {
+                future.cause().printStackTrace();
+                future.channel().close();
             }
         }
     };