更新

src/com/hellogithub/servlet/countNumServlet.java

@@ -40,9 +40,7 @@ public class countNumServlet extends HttpServlet {
         resp.setContentType("application/json;charset=UTF-8");
 
         PrintWriter writer = resp.getWriter();
-        String  str= String.valueOf(projectService.countAll());
-        String jsonString = JSONObject.toJSONString(str);
-        writer.println(jsonString);
+        writer.println(projectService.countAll());
         writer.close();
     }