JAVA-EE实际开发中解决重定向和转发的问题------计算机网络经典

绝地灬酷狼 2024-02-22 08:51 31阅读 0赞

>     package com.bjpowernode.javaweb.servlet;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     public class StudentSaveServlet extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //保存到数据库
>             String id = request.getParameter("id");
>             String title = request.getParameter("title");
>             String rating = request.getParameter("rating");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "insert into t_movie(id,title,rating) values(?,?,?)";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,null);
>                 statement.setString(2,title);
>                 statement.setString(3,rating);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null) {
>                     try {
>                         connection.rollback();
>                     } catch (SQLException ex) {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             //保存成功跳转到成功页面
>             if(count == 1)
>             {
>                 //转发是同一个请求,所以一直刷新会一直发出原请求,导致存入超多重复数据
>     //            request.getRequestDispatcher("/index.html").forward(request,response);
>                 response.sendRedirect(request.getContextPath() + "/index.html");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.html");
>     //            request.getRequestDispatcher("/Error.html").forward(request,response);
>             }
>         }
>     }
> 
>     package com.bjpowernode.javaweb.servlet;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     public class StudentSaveServlet extends HttpServlet
>     {
>         @Override
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //保存到数据库
>             String id = request.getParameter("id");
>             String title = request.getParameter("title");
>             String rating = request.getParameter("rating");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "insert into t_movie(id,title,rating) values(?,?,?)";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,null);
>                 statement.setString(2,title);
>                 statement.setString(3,rating);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null) {
>                     try {
>                         connection.rollback();
>                     } catch (SQLException ex) {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             //保存成功跳转到成功页面
>             if(count == 1)
>             {
>                 //转发是同一个请求,所以一直刷新会一直发出原请求,导致存入超多重复数据
>     //            request.getRequestDispatcher("/index.html").forward(request,response);
>                 response.sendRedirect(request.getContextPath() + "/index.html");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.html");
>     //            request.getRequestDispatcher("/Error.html").forward(request,response);
>             }
>         }
>     }

>     <!DOCTYPE html>
>     <html>
>     	<head>
>     		<meta charset="utf-8">
>     		<title>欢迎页</title>
>     	</head>
>     	<body>
>     
>     		<h1><a href="/OA/dept/list">查看部门列表</a></h1>
>     	</body>
>     </html>
> 
>     <!DOCTYPE html>
>     <html>
>         <head>
>            <meta charset="utf-8">
>            <title>欢迎页</title>
>         </head>
>         <body>
>     
>            <h1><a href="/OA/dept/list">查看部门列表</a></h1>
>         </body>
>     </html>

>     <!DOCTYPE html>
>     <html lang="en">
>     <head>
>         <meta charset="UTF-8">
>         <title>Title</title>
>     </head>
>     <body>
>         <form action="/OA/saveStu" method="get">
>             <h1>ID</h1><input type="text" name="id"><br>
>             <h1>名称</h1><input type="text" name="title"><br>
>             <h1>评分</h1><input type="text" name="rating"><br>
>             <input type="submit" value="提交">
>         </form>
>     </body>
>     </html>
> 
>     <!DOCTYPE html>
>     <html lang="en">
>     <head>
>         <meta charset="UTF-8">
>         <title>Title</title>
>     </head>
>     <body>
>         <form action="/OA/saveStu" method="get">
>             <h1>ID</h1><input type="text" name="id"><br>
>             <h1>名称</h1><input type="text" name="title"><br>
>             <h1>评分</h1><input type="text" name="rating"><br>
>             <input type="submit" value="提交">
>         </form>
>     </body>
>     </html>

>     <?xml version="1.0" encoding="UTF-8"?>
>     <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
>              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>              xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
>              version="4.0">
>         <servlet>
>             <servlet-name>listDept</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DeptListServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>listDept</servlet-name>
>     
>             <url-pattern>/dept/list</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>detail</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DetailServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>detail</servlet-name>
>             <url-pattern>/dept/detail</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>delete</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DeleteServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>delete</servlet-name>
>             <url-pattern>/dept/delete</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>save</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.SaveServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>save</servlet-name>
>             <url-pattern>/dept/save</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>edit</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.EditServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>edit</servlet-name>
>             <url-pattern>/dept/edit</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>modify</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.ModifyServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>modify</servlet-name>
>             <url-pattern>/dept/modify</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>A</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.AServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>A</servlet-name>
>             <url-pattern>/A</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>B</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.BServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>B</servlet-name>
>             <url-pattern>/B</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>saveStu</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.StudentSaveServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>saveStu</servlet-name>
>             <url-pattern>/saveStu</url-pattern>
>         </servlet-mapping>
>     </web-app>
> 
>     <?xml version="1.0" encoding="UTF-8"?>
>     <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
>              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>              xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
>              version="4.0">
>         <servlet>
>             <servlet-name>listDept</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DeptListServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>listDept</servlet-name>
>     
>             <url-pattern>/dept/list</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>detail</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DetailServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>detail</servlet-name>
>             <url-pattern>/dept/detail</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>delete</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.DeleteServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>delete</servlet-name>
>             <url-pattern>/dept/delete</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>save</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.SaveServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>save</servlet-name>
>             <url-pattern>/dept/save</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>edit</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.EditServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>edit</servlet-name>
>             <url-pattern>/dept/edit</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>modify</servlet-name>
>             <servlet-class>com.bjpowernode.oa.web.action.ModifyServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>modify</servlet-name>
>             <url-pattern>/dept/modify</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>A</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.AServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>A</servlet-name>
>             <url-pattern>/A</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>B</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.BServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>B</servlet-name>
>             <url-pattern>/B</url-pattern>
>         </servlet-mapping>
>         <servlet>
>             <servlet-name>saveStu</servlet-name>
>             <servlet-class>com.bjpowernode.javaweb.servlet.StudentSaveServlet</servlet-class>
>         </servlet>
>         <servlet-mapping>
>             <servlet-name>saveStu</servlet-name>
>             <url-pattern>/saveStu</url-pattern>
>         </servlet-mapping>
>     </web-app>