添加动态显示月刊项目,推荐项目

src/com/hellogithub/dao/projectDao.java

@@ -24,7 +24,7 @@ public class projectDao {
         try {
             Connection conn = JdbcUtils.getConnection();
             QueryRunner runner = new QueryRunner();
-            String sql = "select * from project where periodicals = ?";
+            String sql = "select * from project where periodicals = ? ORDER BY categoryId";
             projectEntityList = runner.query(conn, sql, new BeanListHandler<>(projectEntity.class), num);
             conn.close();
         } catch (SQLException e) {
@@ -221,4 +221,23 @@ public class projectDao {
         }
         return categoryEntityList;
     }
+
+    //返回项目最大数字
+    public int retMaxProId(){
+        projectEntity projectEntity;
+        int num ;
+        try {
+            Connection conn = JdbcUtils.getConnection();
+            QueryRunner runner = new QueryRunner();
+            String sql = "select * from project Order By ProjectId DESC limit 1";
+            projectEntity = runner.query(conn, sql,new BeanHandler<>(projectEntity.class));
+            num = projectEntity.getProjectId();
+            conn.close();
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+        return num;
+    }
+
+
 }

src/com/hellogithub/service/projectService.java

@@ -8,10 +8,7 @@ import com.hellogithub.dao.projectDao;
 import com.hellogithub.entity.categoryEntity;
 import com.hellogithub.entity.projectEntity;
 
-import java.util.ArrayList;
+import java.util.*;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
 
 
 public class projectService {
@@ -24,16 +21,30 @@ public class projectService {
      *
      * @param num
      */
-    public List<projectEntity> retTerm(String num){
+    public String retTerm(String num){
         List<projectEntity> projectEntityList = projectDao.retTerm(num);
+        List<projectEntity> projectEntityListTem =new ArrayList<>();
+        Map<String,List<projectEntity>> dataMap= new HashMap<>();
+        String tem =null;
+        String now =null;
         for(int i =0;i<projectEntityList.size();i++)
         {
+
             projectEntity projectEntity = projectEntityList.get(i);
             categoryEntity categoryEntity = categoryDao.retNum(projectEntity.getCategoryId());
             projectEntity.setCategoryName(categoryEntity.getCategoryName());
+            now =projectEntity.getCategoryName();
+
+            if(i == 0) tem = now;
+            if(!tem.equals(now)){
+                tem=now;
+                dataMap.put(tem,projectEntityListTem);
+                projectEntityListTem = new ArrayList<>();
+            }
+                projectEntityListTem.add(projectEntity);
 
         }
-        return projectDao.retTerm(num);
+        return JSONObject.toJSONString(dataMap);
 
 
     }
@@ -145,4 +156,16 @@ public class projectService {
         dataMap.put("CategoryName",strs);
         return JSONArray.toJSONString(dataMap);
     }
+
+    public List<projectEntity> randomSelect(){
+        List<projectEntity> projectEntityList = null;
+        long t = System.currentTimeMillis();
+        Random random = new Random(t);
+        for(int i=0;i<5;i++)
+        {
+            projectEntity projectEntity = projectDao.selectProById(String.valueOf(random.nextInt(projectDao.retMaxProId())));
+            projectEntityList.add(projectEntity);
+        }
+        return projectEntityList;
+    }
 }

src/com/hellogithub/servlet/randomSelectProServlet.java

@@ -0,0 +1,46 @@
+package com.hellogithub.servlet;
+
+import com.alibaba.fastjson.JSONObject;
+import com.hellogithub.service.projectService;
+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 java.io.IOException;
+import java.io.PrintWriter;
+
+@WebServlet("/randomSelectPro")
+public class randomSelectProServlet extends HttpServlet {
+    private com.hellogithub.service.projectService projectService=new projectService();
+    @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");
+
+        PrintWriter writer = resp.getWriter();
+        String jsonString = JSONObject.toJSONString(projectService.randomSelect());
+        writer.println(jsonString);
+        writer.close();
+    }
+}

src/com/hellogithub/servlet/selectTermServlet.java

@@ -39,12 +39,10 @@ public class selectTermServlet extends HttpServlet {
         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");
         //按照分类返回期刊
-        String num = req.getParameter("xxxxxxx");
+        String num = req.getParameter("id");
         PrintWriter writer = resp.getWriter();
-        String jsonString = JSONObject.toJSONString(projectService.retTerm(num));
+        writer.println(projectService.retTerm(num));
-        setResultOK("success",writer);
+//        setResultOK("123",writer);
-        writer.println(jsonString);
-        writer.close();
     }
 
     public void setResult(Integer code, String msg, PrintWriter writer) {