点赞

src/com/hellogithub/dao/commentDao.java

@@ -70,5 +70,19 @@ public class commentDao {
         }
         return commentEntityList;
     }
+    public int addLikeNum(int commentId)
+    {
+        int num ;
+        try {
+            Connection conn = JdbcUtils.getConnection();
+            QueryRunner runner = new QueryRunner();
+            String sql = "update  comment set likeNum = likeNum +1 where commentId = ?  and isValid = 1";
+            num = runner.update(conn, sql,commentId);
+            conn.close();
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
 
+        return num ;
+    }
 }

src/com/hellogithub/service/commentService.java

@@ -63,4 +63,16 @@ public class commentService {
 
         return JSONObject.toJSONString(commentEntityList);
     }
+    public String addLikeNum(int commentId){
+        String tip="";
+        int num = commentDao.addLikeNum(commentId);
+        if(num == 1)
+        {
+            tip="点赞成功";
+        }
+        else{
+            tip= "点赞失败";
+        }
+        return tip;
+    }
 }

src/com/hellogithub/servlet/addLikeServlet.java

@@ -0,0 +1,76 @@
+package com.hellogithub.servlet;
+
+import com.alibaba.fastjson.JSONObject;
+import com.hellogithub.entity.userEntity;
+import com.hellogithub.service.commentService;
+import jakarta.servlet.ServletConfig;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebServlet;
+import jakarta.servlet.http.HttpServlet;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import jakarta.servlet.http.HttpSession;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.HashMap;
+
+@WebServlet("/addLike")
+public class addLikeServlet extends HttpServlet {
+
+    private commentService commentService = new commentService();
+    @Override
+    public void init(ServletConfig config) throws ServletException {
+
+    }
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        doPost(req,resp);
+    }
+
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        resp.setCharacterEncoding("UTF-8");
+        resp.setContentType("text/html; charset=utf-8");
+        //        设置响应头允许ajax跨域访问
+        String curOrigin = req.getHeader("Origin");
+        resp.setHeader("Access-Control-Allow-Origin", curOrigin == null ? "true" : curOrigin);
+        resp.setHeader("Access-Control-Allow-Credentials", "true");
+        resp.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, HEAD");
+        resp.setHeader("Access-Control-Max-Age", "3600");
+        resp.setHeader("Access-Control-Allow-Headers", "access-control-allow-origin, authority, content-type, version-info, X-Requested-With");
+        resp.setContentType("application/json;charset=UTF-8");
+        //
+        String proId = req.getParameter("id");
+        PrintWriter writer = resp.getWriter();
+        HttpSession session  =req.getSession();
+        userEntity userEntity=(userEntity)session.getAttribute("user");
+        if(userEntity ==null)
+        {
+            setResultError("用户未登录", writer);
+        }
+        else{
+            commentService.addLikeNum(Integer.parseInt(proId));
+        }
+
+
+    }
+
+    public void setResult(Integer code, String msg, PrintWriter writer) {
+        HashMap<String, Object> result = new HashMap<>();
+        result.put("code", code);
+        result.put("msg", msg);
+        String jsonString = JSONObject.toJSONString(result);
+        writer.println(jsonString);
+        writer.close();
+    }
+
+    public void setResultError(String msg, PrintWriter writer) {
+        setResult(500, msg, writer);
+    }
+
+    public void setResultOK(String msg, PrintWriter writer) {
+        setResult(200, msg, writer);
+    }
+}