Update build.gradle with log4j dependency

.deepsource.toml

@@ -17,4 +17,4 @@ enabled = true
 
 [[transformers]]
 name = "google-java-format"
-enabled = true
+enabled = true

web/build.gradle

@@ -15,6 +15,8 @@ dependencies {
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
 
     implementation group: 'javax.servlet', name: 'javax.servlet-api', version: '3.1.0'
+    implementation group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.14.1'
+    implementation group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.14.1'
 }
 
 test {

web/src/main/java/com/example/server/Server.java

@@ -1,62 +1,70 @@
 package com.example.server;
+
+import java.io.IOException;
+import java.sql.*;
 import javax.servlet.ServletException;
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import java.io.IOException;
-import java.sql.*;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 public class Server extends HttpServlet {
 
-    static final String DB_URL = "jdbc:mysql://localhost/users";
-    static Connection conn;
-
-    @Override
-    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-        Cookie c = new Cookie("uid", req.getSession().getId());
-        // For older browsers?
-        c.setSecure(false);
-        resp.addCookie(c);
-        resp.setHeader("Access-Control-Allow-Origin", "*");
-
-        Boolean b = Boolean.parseBoolean(req.getParameter("winCondition"));
-        int ticketNumber = Integer.parseInt(req.getParameter("ticket"));
-        try {
-            Statement s = conn.createStatement();
-            s.execute("SELECT userName, isWin FROM users WHERE uid = " + ticketNumber + ";");
-            ResultSet r = s.getResultSet();
-
-            if (r.getBoolean("isWin") && b) {
-                resp.getWriter().write("You win, " + r.getString("userName"));
-            } else {
-                resp.getWriter().write("You lose, " + r.getString("userName"));
-            }
-        } catch (SQLException throwables) {
-            throwables.printStackTrace();
-        }
-        resp.setStatus(200);
-    }
+  static final String DB_URL = "jdbc:mysql://localhost/users";
+  static Connection conn;
 
-    @Override
-    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-        super.doPost(req, resp);
-    }
+  private static final Logger logger = LogManager.getLogger(Server.class);
+
+  @Override
+  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
+      throws ServletException, IOException {
+    Cookie c = new Cookie("uid", req.getSession().getId());
+    // For older browsers?
+    c.setSecure(false);
+    resp.addCookie(c);
+    resp.setHeader("Access-Control-Allow-Origin", "*");
+
+    logger.info("user agent: " + req.getHeader("user-agent"));
 
-    @Override
-    public void destroy() {
-        super.destroy();
+    Boolean b = Boolean.parseBoolean(req.getParameter("winCondition"));
+    int ticketNumber = Integer.parseInt(req.getParameter("ticket"));
+    try {
+      Statement s = conn.createStatement();
+      s.execute("SELECT userName, isWin FROM users WHERE uid = " + ticketNumber + ";");
+      ResultSet r = s.getResultSet();
+
+      if (r.getBoolean("isWin") && b) {
+        resp.getWriter().write("You win, " + r.getString("userName"));
+      } else {
+        resp.getWriter().write("You lose, " + r.getString("userName"));
+      }
+    } catch (SQLException throwables) {
+      throwables.printStackTrace();
     }
+    resp.setStatus(200);
+  }
+
+  @Override
+  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
+      throws ServletException, IOException {
+    super.doPost(req, resp);
+  }
 
-    @Override
-    public void init() throws ServletException {
-        super.init();
+  @Override
+  public void destroy() {
+    super.destroy();
+  }
 
-        try {
-            conn = DriverManager.getConnection(DB_URL, "user", "");
-        } catch (SQLException throwables) {
-            throwables.printStackTrace();
-        }
+  @Override
+  public void init() throws ServletException {
+    super.init();
 
+    try {
+      conn = DriverManager.getConnection(DB_URL, "user", "");
+    } catch (SQLException throwables) {
+      throwables.printStackTrace();
     }
+  }
 }