Create base servlet class

1 files changed, 76 insertions, 0 deletions

diff --git a/src/org/traccar/http/BaseServlet.java b/src/org/traccar/http/BaseServlet.java
new file mode 100644
index 000000000..9249b33d8
--- /dev/null
+++ b/src/org/traccar/http/BaseServlet.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2015 Anton Tananaev (anton.tananaev@gmail.com)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.http;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.security.AccessControlException;
+import javax.json.Json;
+import javax.json.JsonObjectBuilder;
+import javax.json.JsonStructure;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+
+public abstract class BaseServlet extends HttpServlet {
+    
+    public static final String USER_ID = "userId";
+    
+    @Override
+    protected final void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        String command = req.getPathInfo();
+        try {
+            if (command == null || !handle(command, req, resp)) {
+                resp.sendError(HttpServletResponse.SC_BAD_REQUEST);
+            }
+        } catch (Exception error) {
+            sendResponse(resp.getWriter(), error);
+        }
+    }
+    
+    protected abstract boolean handle(String command, HttpServletRequest req, HttpServletResponse resp) throws Exception;
+    
+    public long getUserId(HttpSession session) {
+        Long userId = (Long) session.getAttribute(USER_ID);
+        if (userId == null) {
+            throw new AccessControlException("User is not logged in");
+        }
+        return userId;
+    }
+    
+    public void sendResponse(Writer writer) throws IOException {
+        JsonObjectBuilder result = Json.createObjectBuilder();
+        result.add("success", true);
+        writer.write(result.build().toString());
+    }
+    
+    public void sendResponse(Writer writer, JsonStructure json) throws IOException {
+        JsonObjectBuilder result = Json.createObjectBuilder();
+        result.add("success", true);
+        result.add("data", json);
+        writer.write(result.build().toString());
+    }
+    
+    public void sendResponse(Writer writer, Exception error) throws IOException {
+        JsonObjectBuilder result = Json.createObjectBuilder();
+        result.add("success", false);
+        result.add("error", error.getMessage());
+        writer.write(result.build().toString());
+    }
+    
+}