根据项目id返回项目信息

src/com/hellogithub/dao/projectDao.java

@@ -169,4 +169,22 @@ public class projectDao {
 //        }
 //        return ;
 //    }
+
+
+    /**
+     * 根据项目ID返回项目所有内容
+     */
+    public projectEntity selectProById(String id ) {
+        projectEntity projectEntity;
+        try {
+            Connection conn = JdbcUtils.getConnection();
+            QueryRunner runner = new QueryRunner();
+            String sql = "select * from project where projectId = ?";
+            projectEntity = runner.query(conn, sql, new BeanHandler<>(projectEntity.class),id);
+            conn.close();
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+        return projectEntity;
+    }
 }

src/com/hellogithub/service/projectService.java

@@ -116,4 +116,11 @@ public class projectService {
         }
         return projectEntityList;
     }
+
+    public projectEntity selectProById(String id ){
+        projectEntity projectEntity = projectDao.selectProById(id);
+        categoryEntity categoryEntity = categoryDao.retNum(projectEntity.getCategoryId());
+        projectEntity.setCategoryName(categoryEntity.getCategoryName());
+        return projectEntity;
+    }
 }

src/com/hellogithub/servlet/selectProByIdServlet.java

@@ -0,0 +1,63 @@
+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;
+import java.util.HashMap;
+@WebServlet("/selectProById")
+public class selectProByIdServlet 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");
+        //按照分类返回期刊
+        String id = req.getParameter("xxxxxxx");
+        PrintWriter writer = resp.getWriter();
+        String jsonString = JSONObject.toJSONString(projectService.selectProById(id));
+        writer.println(jsonString);
+        writer.close();
+    }
+    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);
+    }
+}