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  • eclipse配置Servlet连接Mysql要注意的几个地方

    用Servlet即把jdbc那套放到继承于HttpServlet的派生类之内,那段代码很简单

        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {       
            response.setCharacterEncoding("Unicode");        
            PrintWriter out=response.getWriter();
            String name=request.getParameter("username");
            String passwd=request.getParameter("passwd");        
          try {
            Class.forName("com.mysql.jdbc.Driver");
        //    Class.forName("com.mysql.cj.jdbc.Driver");
            Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/stu", "root", "root");
            //Statement stmt=conn.createStatement();
            //ResultSet rs=stmt.executeQuery(sql);  //查询    
            java.sql.PreparedStatement pstmt=conn.prepareStatement("select * from tb_user where name=? and password=?");
            pstmt.setString(1, name);
            pstmt.setString(2, passwd);
            //System.out.println();
            ResultSet rs=pstmt.executeQuery();
            rs.beforeFirst();
            if(rs.next())
            {
                out.println(rs.getString(1)+":"+rs.getString(2));
            }
            else{
                out.println("不存在该用户!");
            }        
            rs.close();
            conn.close();
        } catch (ClassNotFoundException | SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }            
        }

      但注意要把jdbc放到tomcat目录中的lib中,不然报的那种错误,确实有点让人看不懂

      还有编码的格式需要注意一下,有时候Mysql数据表中的编码,会与界面的编码格式不一致,比如我这是Unicode的

        response.setCharacterEncoding("Unicode");  

     把Web.xml的配置文件也放上吧

      <servlet>
        <servlet-name>Login</servlet-name>
        <servlet-class>com.LoginServlet</servlet-class>
      </servlet>
      <servlet-mapping>
        <servlet-name>Login</servlet-name>
        <url-pattern>/ServerCoding1/aaa</url-pattern>
      </servlet-mapping>

    调用类似

    <a href="aaa">跳转<a/>

       
       <form action="ServerCoding1/aaa" method="post">
    
       <input type="submit" value="跳转">
         </form>
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  • 原文地址:https://www.cnblogs.com/ironSheet-SRS/p/10015766.html
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