ADD file via upload

ClaimServlet.java

@@ -0,0 +1,38 @@
+package com.lostfound.servlet;
+
+import com.lostfound.dao.InMemoryDAO;
+import com.lostfound.model.Item;
+import com.lostfound.util.SessionUtil;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebServlet("/claim")
+public class ClaimServlet extends HttpServlet {
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        if (!SessionUtil.isLoggedIn(req)) {
+            resp.sendRedirect("login.jsp");
+            return;
+        }
+
+        String itemId = req.getParameter("id");
+        Item item = InMemoryDAO.getItem(itemId);
+        if (item == null) {
+            resp.sendRedirect("search.jsp?error=物品不存在");
+            return;
+        }
+
+        req.setAttribute("item", item);
+        req.getRequestDispatcher("/claim-confirm.jsp").forward(req, resp);
+    }
+
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
+        String itemId = req.getParameter("itemId");
+        InMemoryDAO.markAsMatched(itemId);
+        resp.sendRedirect("my-items.jsp?msg=认领成功！对方已获得积分。");
+    }
+}