- refactor out common things from AjaxServlet so it can be used elsewhere

- fix some guice stuff

src/net/socialgamer/cah/AjaxServlet.java

@@ -16,9 +16,6 @@ import javax.servlet.http.HttpSession;
 import net.socialgamer.cah.handlers.Handler;
 import net.socialgamer.cah.handlers.Handlers;
 
-import org.json.simple.JSONObject;
-import org.json.simple.JSONValue;
-
 import com.google.inject.Guice;
 import com.google.inject.Injector;
 
@@ -29,7 +26,7 @@ import com.google.inject.Injector;
  * This servlet is only used for client actions, not for long-polling.
  */
 @WebServlet("/AjaxServlet")
-public class AjaxServlet extends HttpServlet {
+public class AjaxServlet extends CahServlet {
   private static final long serialVersionUID = 1L;
 
   private final Injector injector;
@@ -42,8 +39,8 @@ public class AjaxServlet extends HttpServlet {
   public AjaxServlet() {
     super();
 
-    this.server = new Server();
+    injector = Guice.createInjector();
-    injector = Guice.createInjector(new CahModule(server));
+    this.server = injector.getInstance(Server.class);
   }
 
   /**
@@ -55,22 +52,14 @@ public class AjaxServlet extends HttpServlet {
   }
 
   /**
-   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
+   * @see CahServlet#doPost(HttpServletRequest request, HttpServletResponse response, HttpSession
+   *      hSession)
    */
   @Override
-  protected void doPost(final HttpServletRequest request, final HttpServletResponse response)
+  protected void handleRequest(final HttpServletRequest request,
-      throws ServletException, IOException {
+      final HttpServletResponse response, final HttpSession hSession) throws ServletException,
-    response.setContentType("application/json");
+      IOException {
     final PrintWriter out = response.getWriter();
-
-    final HttpSession hSession = request.getSession(true);
-    if (hSession.isNew()) {
-      // they should have gotten a session from the index page.
-      // they probably don't have cookies on.
-      returnError(out, "Session not detected. Make sure you have cookies enabled.");
-      return;
-    }
-
     int serial = -1;
     if (request.getParameter("serial") != null) {
       try {
@@ -94,25 +83,10 @@ public class AjaxServlet extends HttpServlet {
       returnError(out, "Invalid operation.", serial);
       return;
     }
-    final Map<String, Object> returnData = handler.handle(request.getParameterMap(), hSession);
+    final Map<String, Object> data = handler.handle(request.getParameterMap(), hSession);
-    returnData.put("serial", serial);
+    data.put("serial", serial);
-    returnData(out, returnData);
+    returnData(out, data);
     return;
   }
 
-  private void returnError(final PrintWriter writer, final String message) {
-    returnError(writer, message, -1);
-  }
-
-  @SuppressWarnings("unchecked")
-  private void returnError(final PrintWriter writer, final String message, final int serial) {
-    final JSONObject ret = new JSONObject();
-    ret.put("error", Boolean.TRUE);
-    ret.put("error_message", message);
-    writer.println(ret.toJSONString());
-  }
-
-  private void returnData(final PrintWriter writer, final Map<String, Object> data) {
-    writer.println(JSONValue.toJSONString(data));
-  }
 }

src/net/socialgamer/cah/CahModule.java

@@ -1,22 +1,14 @@
 package net.socialgamer.cah;
 
-import net.socialgamer.cah.data.ConnectedUsers;
-
 import com.google.inject.AbstractModule;
+import com.google.inject.Singleton;
 
 
 public class CahModule extends AbstractModule {
 
-  private final Server server;
-
-  public CahModule(final Server server) {
-    this.server = server;
-  }
-
   @Override
   protected void configure() {
     // TODO Auto-generated method stub
-    bind(ConnectedUsers.class).toInstance(server.getConnectedUsers());
+    bind(Server.class).in(Singleton.class);
   }
-
 }

src/net/socialgamer/cah/CahServlet.java

@@ -0,0 +1,101 @@
+package net.socialgamer.cah;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.Map;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+
+import org.json.simple.JSONObject;
+import org.json.simple.JSONValue;
+
+
+/**
+ * Servlet implementation class CahServlet
+ */
+// @WebServlet("/CahServlet")
+public abstract class CahServlet extends HttpServlet {
+  private static final long serialVersionUID = 1L;
+
+  /**
+   * @see HttpServlet#HttpServlet()
+   */
+  public CahServlet() {
+    super();
+    // TODO Auto-generated constructor stub
+  }
+
+  /**
+   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
+   */
+  @Override
+  protected void doPost(final HttpServletRequest request, final HttpServletResponse response)
+      throws ServletException, IOException {
+    response.setContentType("application/json");
+
+    final HttpSession hSession = request.getSession(true);
+    if (hSession.isNew()) {
+      // they should have gotten a session from the index page.
+      // they probably don't have cookies on.
+      returnError(response.getWriter(), "Session not detected. Make sure you have cookies enabled.");
+    } else {
+      handleRequest(request, response, hSession);
+    }
+  }
+
+  /**
+   * Handles a request from a CAH client. A session is guaranteed to exist at this point.
+   * 
+   * @param request
+   * @param response
+   * @param hSession
+   * @throws ServletException
+   * @throws IOException
+   */
+  protected abstract void handleRequest(final HttpServletRequest request,
+      final HttpServletResponse response, final HttpSession hSession) throws ServletException,
+      IOException;
+
+  /**
+   * Return an error to the client. Prefer to use the PrintWriter,String,int version if you know the
+   * request serial number.
+   * 
+   * @param writer
+   * @param message
+   */
+  protected void returnError(final PrintWriter writer, final String message) {
+    returnError(writer, message, -1);
+  }
+
+  /**
+   * Return an error to the client.
+   * 
+   * @param writer
+   * @param message
+   * @param serial
+   */
+  @SuppressWarnings("unchecked")
+  protected void returnError(final PrintWriter writer, final String message, final int serial) {
+    final JSONObject ret = new JSONObject();
+    ret.put("error", Boolean.TRUE);
+    ret.put("error_message", message);
+    writer.println(ret.toJSONString());
+  }
+
+  /**
+   * Return response data to the client.
+   * 
+   * @param writer
+   *          Writer for the response.
+   * @param data
+   *          Key-value data to return as the response.
+   */
+  protected void returnData(final PrintWriter writer, final Map<String, Object> data) {
+    writer.println(JSONValue.toJSONString(data));
+  }
+
+}

src/net/socialgamer/cah/Server.java

@@ -2,7 +2,10 @@ package net.socialgamer.cah;
 
 import net.socialgamer.cah.data.ConnectedUsers;
 
+import com.google.inject.Singleton;
 
+
+@Singleton
 public class Server {
   private final ConnectedUsers users;
 
@@ -10,6 +13,7 @@ public class Server {
     users = new ConnectedUsers();
   }
 
+  // TODO figure out if I can just get this to inject directly
   public ConnectedUsers getConnectedUsers() {
     return this.users;
   }