Small cleanup

.gitignore

@@ -0,0 +1,16 @@
+# Eclipse
+.classpath
+.project
+.settings/
+
+# Intellij
+.idea/
+*.iml
+*.iws
+
+# Mac
+.DS_Store
+
+# Maven
+log/
+target/

README.md

@@ -1,5 +1,6 @@
+# Gossip
 
-Gossip protocol is a method for a group of nodes to discover and check the livelyness of a cluster. More information can be found at http://en.wikipedia.org/wiki/Gossip_protocol.
+Gossip protocol is a method for a group of nodes to discover and check the liveliness of a cluster. More information can be found at http://en.wikipedia.org/wiki/Gossip_protocol.
 
 The original implementation was forked from https://code.google.com/p/java-gossip/. Several bug fixes and changes have already been added.
 
@@ -8,16 +9,19 @@ Usage
 
 To gossip you need one or more seed nodes. Seed is just a list of places to initially connect to.
 
+```java
   GossipSettings settings = new GossipSettings();
   int seedNodes = 3;
-    ArrayList<GossipMember> startupMembers = new ArrayList<GossipMember>();
+  List<GossipMember> startupMembers = new ArrayList<>();
   for (int i = 1; i < seedNodes+1; ++i) {
     startupMembers.add(new RemoteGossipMember("127.0.0." + i, 2000, i + ""));
   }
+```
 
 Here we start five gossip processes and check that they discover each other. (Normally these are on different hosts but here we give each process a distinct local ip.
 
-    ArrayList<GossipService> clients = new ArrayList<GossipService>();
+```java
+  List<GossipService> clients = new ArrayList<>();
   int clusterMembers = 5;
   for (int i = 1; i < clusterMembers+1; ++i) {
     GossipService gossipService = new GossipService("127.0.0." + i, 2000, i + "",
@@ -25,24 +29,30 @@ Here we start five gossip processes and check that they discover each other. (No
     clients.add(gossipService);
     gossipService.start();
   }
+```
 
 Later we can check that the nodes discover each other
 
+```java
   Thread.sleep(10000);
   for (int i = 0; i < clusterMembers; ++i) {
     Assert.assertEquals(4, clients.get(i).get_gossipManager().getMemberList().size());
   }
+```
 
 Event Listener
 ------
 
 The status can be polled using the getters that return immutable lists.
 
+```java
    List<LocalGossipMember> getMemberList()
    public List<LocalGossipMember> getDeadList()
+```
 
 Users can also attach an event listener:
 
+```java
   GossipService gossipService = new GossipService("127.0.0." + i, 2000, i + "", LogLevel.DEBUG,
           startupMembers, settings,
           new GossipListener(){
@@ -51,6 +61,7 @@ Users can also attach an event listener:
       System.out.println(member+" "+ state);
     }
   });
+```
 
 
 Maven
@@ -59,8 +70,10 @@ Maven
 
 You can get this software from maven central.
 
+```xml
   <dependency>
        <groupId>io.teknek</groupId>
       <artifactId>gossip</artifactId>
       <version>${pick_the_latest_version}</version>
   </dependency>
+```

src/main/java/com/google/code/gossip/GossipMember.java

@@ -16,8 +16,8 @@ public abstract class GossipMember implements Comparable<GossipMember>{
 	public static final String JSON_PORT = "port";
 	public static final String JSON_HEARTBEAT = "heartbeat";
 	public static final String JSON_ID = "id";
-	protected String _host;
-	protected int _port;
+	protected final String _host;
+	protected final int _port;
 	protected int _heartbeat;
 	protected String _id;
 

src/main/java/com/google/code/gossip/GossipRunner.java

@@ -7,7 +7,6 @@ import java.io.IOException;
 import org.json.JSONException;
 
 public class GossipRunner {
-  private StartupSettings _settings;
 
   public static void main(String[] args) {
     File configFile;
@@ -26,9 +25,9 @@ public class GossipRunner {
     if (configFile != null && configFile.exists()) {
       try {
         System.out.println("Parsing the configuration file...");
-        _settings = StartupSettings.fromJSONFile(configFile);
+        StartupSettings _settings = StartupSettings.fromJSONFile(configFile);
         GossipService gossipService = new GossipService(_settings);
-        System.out.println("Gossip service successfully inialized, let's start it...");
+        System.out.println("Gossip service successfully initialized, let's start it...");
         gossipService.start();
       } catch (FileNotFoundException e) {
         System.err.println("The given file is not found!");

src/main/java/com/google/code/gossip/GossipService.java

@@ -1,9 +1,9 @@
 package com.google.code.gossip;
 
 import java.net.InetAddress;
-import java.net.SocketException;
 import java.net.UnknownHostException;
-import java.util.ArrayList;
+import java.util.List;
+
 import org.apache.log4j.Logger;
 
 import com.google.code.gossip.event.GossipListener;
@@ -37,12 +37,11 @@ public class GossipService {
   /**
    * Setup the client's lists, gossiping parameters, and parse the startup config file.
    *
-   * @throws SocketException
    * @throws InterruptedException
    * @throws UnknownHostException
    */
   public GossipService(String ipAddress, int port, String id, int logLevel,
-          ArrayList<GossipMember> gossipMembers, GossipSettings settings, GossipListener listener)
+          List<GossipMember> gossipMembers, GossipSettings settings, GossipListener listener)
           throws InterruptedException, UnknownHostException {
     _gossipManager = new RandomGossipManager(ipAddress, port, id, settings, gossipMembers, listener);
   }

src/main/java/com/google/code/gossip/GossipTimeoutTimer.java

@@ -14,15 +14,15 @@ import javax.management.timer.Timer;
  */
 public class GossipTimeoutTimer extends Timer {
 
-  private long _sleepTime;
-  private LocalGossipMember _source;
+  private final long _sleepTime;
+  private final LocalGossipMember _source;
 
   /**
    * Constructor. Creates a reset-able timer that wakes up after millisecondsSleepTime.
    *
    * @param millisecondsSleepTime
    *          The time for this timer to wait before an event.
-   * @param service
+   * @param notificationListener
    * @param member
    */
   public GossipTimeoutTimer(long millisecondsSleepTime, NotificationListener notificationListener,

src/main/java/com/google/code/gossip/LocalGossipMember.java

@@ -10,19 +10,19 @@ import javax.management.NotificationListener;
  */
 public class LocalGossipMember extends GossipMember {
   /** The timeout timer for this gossip member. */
-  private transient GossipTimeoutTimer timeoutTimer;
+  private final transient GossipTimeoutTimer timeoutTimer;
 
   /**
    * Constructor.
    *
-   * @param host
+   * @param hostname
    *          The hostname or IP address.
    * @param port
    *          The port number.
+   * @param id
    * @param heartbeat
    *          The current heartbeat.
-   * @param gossipService
-   *          The GossipService object.
+   * @param notificationListener
    * @param cleanupTimeout
    *          The cleanup timeout for this gossip member.
    */

src/main/java/com/google/code/gossip/RemoteGossipMember.java

@@ -11,7 +11,7 @@ public class RemoteGossipMember extends GossipMember {
   /**
    * Constructor.
    *
-   * @param host
+   * @param hostname
    *          The hostname or IP address.
    * @param port
    *          The port number.
@@ -25,7 +25,7 @@ public class RemoteGossipMember extends GossipMember {
   /**
    * Construct a RemoteGossipMember with a heartbeat of 0.
    *
-   * @param host
+   * @param hostname
    *          The hostname or IP address.
    * @param port
    *          The port number.

src/main/java/com/google/code/gossip/StartupSettings.java

@@ -6,6 +6,7 @@ import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.List;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -25,10 +26,10 @@ public class StartupSettings {
   private int _logLevel;
 
   /** The gossip settings used at startup. */
-  private GossipSettings _gossipSettings;
+  private final GossipSettings _gossipSettings;
 
   /** The list with gossip members to start with. */
-  private ArrayList<GossipMember> _gossipMembers;
+  private final List<GossipMember> _gossipMembers;
 
   /**
    * Constructor.
@@ -50,7 +51,7 @@ public class StartupSettings {
     _port = port;
     _logLevel = logLevel;
     _gossipSettings = gossipSettings;
-    _gossipMembers = new ArrayList<GossipMember>();
+    _gossipMembers = new ArrayList<>();
   }
 
   /**
@@ -115,7 +116,7 @@ public class StartupSettings {
    *
    * @return The gossip members.
    */
-  public ArrayList<GossipMember> getGossipMembers() {
+  public List<GossipMember> getGossipMembers() {
     return _gossipMembers;
   }
 

src/main/java/com/google/code/gossip/event/GossipState.java

@@ -2,7 +2,7 @@ package com.google.code.gossip.event;
 
 public enum GossipState {
   UP("up"), DOWN("down");
-  private String state;
+  private final String state;
 
   private GossipState(String state){
     this.state = state;

src/main/java/com/google/code/gossip/examples/GossipExample.java

@@ -3,6 +3,7 @@ package com.google.code.gossip.examples;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
+import java.util.List;
 
 import com.google.code.gossip.GossipMember;
 import com.google.code.gossip.GossipService;
@@ -41,14 +42,14 @@ public class GossipExample extends Thread {
     try {
       GossipSettings settings = new GossipSettings();
 
-      ArrayList<GossipService> clients = new ArrayList<GossipService>();
+      List<GossipService> clients = new ArrayList<>();
 
       // Get my ip address.
       String myIpAddress = InetAddress.getLocalHost().getHostAddress();
 
       // Create the gossip members and put them in a list and give them a port number starting with
       // 2000.
-      ArrayList<GossipMember> startupMembers = new ArrayList<GossipMember>();
+      List<GossipMember> startupMembers = new ArrayList<>();
       for (int i = 0; i < NUMBER_OF_CLIENTS; ++i) {
         startupMembers.add(new RemoteGossipMember(myIpAddress, 2000 + i, ""));
       }

src/main/java/com/google/code/gossip/manager/ActiveGossipThread.java

@@ -14,7 +14,7 @@ import com.google.code.gossip.LocalGossipMember;
  */
 abstract public class ActiveGossipThread implements Runnable {
 
-  private GossipManager _gossipManager;
+  private final GossipManager _gossipManager;
 
   private final AtomicBoolean _keepRunning;
 

src/main/java/com/google/code/gossip/manager/GossipManager.java

@@ -28,20 +28,20 @@ public abstract class GossipManager extends Thread implements NotificationListen
   public static final Logger LOGGER = Logger.getLogger(GossipManager.class);
   public static final int MAX_PACKET_SIZE = 102400;
 
-  private ConcurrentSkipListMap<LocalGossipMember,GossipState> members;
-  private LocalGossipMember _me;
-  private GossipSettings _settings;
-  private AtomicBoolean _gossipServiceRunning;
-  private ExecutorService _gossipThreadExecutor;
-  private Class<? extends PassiveGossipThread> _passiveGossipThreadClass;
-  private PassiveGossipThread passiveGossipThread;
-  private Class<? extends ActiveGossipThread> _activeGossipThreadClass;
+  private final ConcurrentSkipListMap<LocalGossipMember,GossipState> members;
+  private final LocalGossipMember _me;
+  private final GossipSettings _settings;
+  private final AtomicBoolean _gossipServiceRunning;
+  private final Class<? extends PassiveGossipThread> _passiveGossipThreadClass;
+  private final Class<? extends ActiveGossipThread> _activeGossipThreadClass;
+  private final GossipListener listener;
   private ActiveGossipThread activeGossipThread;
-  private GossipListener listener;
+  private PassiveGossipThread passiveGossipThread;
+  private ExecutorService _gossipThreadExecutor;
 
   public GossipManager(Class<? extends PassiveGossipThread> passiveGossipThreadClass,
           Class<? extends ActiveGossipThread> activeGossipThreadClass, String address, int port,
-          String id, GossipSettings settings, ArrayList<GossipMember> gossipMembers, 
+          String id, GossipSettings settings, List<GossipMember> gossipMembers,
           GossipListener listener) {
     _passiveGossipThreadClass = passiveGossipThreadClass;
     _activeGossipThreadClass = activeGossipThreadClass;
@@ -119,8 +119,6 @@ public abstract class GossipManager extends Thread implements NotificationListen
   /**
    * Starts the client. Specifically, start the various cycles for this protocol. Start the gossip
    * thread and start the receiver thread.
-   * 
-   * @throws InterruptedException
    */
   public void run() {
     for (LocalGossipMember member : members.keySet()) {
@@ -160,7 +158,7 @@ public abstract class GossipManager extends Thread implements NotificationListen
     activeGossipThread.shutdown();
     try {
       boolean result = _gossipThreadExecutor.awaitTermination(1000, TimeUnit.MILLISECONDS);
-      if (result == false){
+      if (!result){
         LOGGER.error("executor shutdown timed out");
       }
     } catch (InterruptedException e) {

src/main/java/com/google/code/gossip/manager/PassiveGossipThread.java

@@ -32,7 +32,7 @@ abstract public class PassiveGossipThread implements Runnable {
   /** The socket used for the passive thread of the gossip service. */
   private DatagramSocket _server;
 
-  private GossipManager _gossipManager;
+  private final GossipManager _gossipManager;
 
   private AtomicBoolean _keepRunning;
 
@@ -73,7 +73,7 @@ abstract public class PassiveGossipThread implements Runnable {
         // A package larger than this would not be possible to be send from a GossipService,
         // since this is check before sending the message.
         // This could normally only occur when the list of members is very big,
-        // or when the packet is misformed, and the first 4 bytes is not the right in anymore.
+        // or when the packet is malformed, and the first 4 bytes is not the right in anymore.
         // For this reason we regards the message.
         if (packet_length <= GossipManager.MAX_PACKET_SIZE) {
           byte[] json_bytes = new byte[packet_length];
@@ -84,7 +84,7 @@ abstract public class PassiveGossipThread implements Runnable {
           GossipService.LOGGER.debug("Received message (" + packet_length + " bytes): "
                   + receivedMessage);
           try {
-            ArrayList<GossipMember> remoteGossipMembers = new ArrayList<GossipMember>();
+            List<GossipMember> remoteGossipMembers = new ArrayList<>();
             RemoteGossipMember senderMember = null;
             GossipService.LOGGER.debug("Received member list:");
             JSONArray jsonArray = new JSONArray(receivedMessage);

src/main/java/com/google/code/gossip/manager/impl/OnlyProcessReceivedPassiveGossipThread.java

@@ -20,6 +20,8 @@ public class OnlyProcessReceivedPassiveGossipThread extends PassiveGossipThread
    * heartbeats that the remote list has with our list. Also, some additional logic is needed to
    * make sure we have not timed out a member and then immediately received a list with that member.
    *
+   * @param gossipManager
+   * @param senderMember
    * @param remoteList
    */
   protected void mergeLists(GossipManager gossipManager, RemoteGossipMember senderMember,

src/main/java/com/google/code/gossip/manager/impl/SendMembersActiveGossipThread.java

@@ -35,8 +35,7 @@ abstract public class SendMembersActiveGossipThread extends ActiveGossipThread {
           GossipService.LOGGER.debug("Sending memberlist to " + dest + ":" + member.getPort());
           jsonArray.put(me.toJSONObject());
           GossipService.LOGGER.debug(me);
-          for (int i = 0; i < memberList.size(); i++) {
-            LocalGossipMember other = memberList.get(i);
+          for (LocalGossipMember other : memberList) {
             jsonArray.put(other.toJSONObject());
             GossipService.LOGGER.debug(other);
           }

src/main/java/com/google/code/gossip/manager/random/RandomActiveGossipThread.java

@@ -11,7 +11,7 @@ import com.google.code.gossip.manager.impl.SendMembersActiveGossipThread;
 public class RandomActiveGossipThread extends SendMembersActiveGossipThread {
 
   /** The Random used for choosing a member to gossip with. */
-  private Random _random;
+  private final Random _random;
 
   public RandomActiveGossipThread(GossipManager gossipManager) {
     super(gossipManager);

src/main/java/com/google/code/gossip/manager/random/RandomGossipManager.java

@@ -1,16 +1,16 @@
 package com.google.code.gossip.manager.random;
 
-import java.util.ArrayList;
-
 import com.google.code.gossip.GossipMember;
 import com.google.code.gossip.GossipSettings;
 import com.google.code.gossip.event.GossipListener;
 import com.google.code.gossip.manager.GossipManager;
 import com.google.code.gossip.manager.impl.OnlyProcessReceivedPassiveGossipThread;
 
+import java.util.List;
+
 public class RandomGossipManager extends GossipManager {
   public RandomGossipManager(String address, int port, String id, GossipSettings settings,
-          ArrayList<GossipMember> gossipMembers, GossipListener listener) {
+          List<GossipMember> gossipMembers, GossipListener listener) {
     super(OnlyProcessReceivedPassiveGossipThread.class, RandomActiveGossipThread.class, address,
             port, id, settings, gossipMembers, listener);
   }

src/test/java/io/teknek/gossip/TenNodeThreeSeedTest.java

@@ -2,6 +2,7 @@ package io.teknek.gossip;
 
 import java.net.UnknownHostException;
 import java.util.ArrayList;
+import java.util.List;
 
 import junit.framework.Assert;
 
@@ -31,11 +32,11 @@ public class TenNodeThreeSeedTest {
   public void abc() throws InterruptedException, UnknownHostException{
     GossipSettings settings = new GossipSettings();
     int seedNodes = 3;
-    ArrayList<GossipMember> startupMembers = new ArrayList<GossipMember>();
+    List<GossipMember> startupMembers = new ArrayList<>();
     for (int i = 1; i < seedNodes+1; ++i) {
       startupMembers.add(new RemoteGossipMember("127.0.0." + i, 2000, i + ""));
     }
-    ArrayList<GossipService> clients = new ArrayList<GossipService>();
+    List<GossipService> clients = new ArrayList<>();
     int clusterMembers = 5;
     for (int i = 1; i < clusterMembers+1; ++i) {
       GossipService gossipService = new GossipService("127.0.0." + i, 2000, i + "", LogLevel.DEBUG,