从studentDAO.java中获取student.java方法“ student1（）”中的空值？

小编典典

从studentDAO.java中获取student.java方法“ student1（）”中的空值？

jsp

学生.java

import java.io.*;

public class Student implements Serializable  {

    String name;
    String id1,phone,clas;

    public Student() {    
    }

    public String showStudent() {
        return  "Name: "+name+" Address: "+clas+" Phone: "+phone+" ID: "+id1;
    }

    public void Student1(String  id,String n,String c,String ph) {
        name=n;
        id1=id;
        phone=ph;
        clas=c;
    }
}

StudentDAO.java

import java.sql.*; 
import java.io.*;

public class StudentDAO implements Serializable {

    static  String id,detailsi,nam,ph,clas,i;

    public void searchinfo(String id2) {
        id=id2;
        try {
            String url="jdbc:ucanaccess://C:\\Users\\Asim Iqbal\\Documents\\IT.accdb";
            Connection conn = DriverManager.getConnection(url);
            String sql= "SELECT * FROM Student WHERE ID=?";
            PreparedStatement  stmt = conn.prepareStatement(sql);
            stmt.setString(1,id);
            ResultSet rs=stmt.executeQuery();
            if (rs.next()) {
                i=rs.getString("ID");
                nam=rs.getString("Name"); 
                clas=rs.getString("Class");
                ph=rs.getString("Phone");
                Student studentinfo=new Student();
                studentinfo.Student1(i, nam, clas, ph);
            }
        } catch (SQLException e) {
        }
    } 
}

second.jsp

<html> 
    <body>
        <% 
            String id =request.getParameter("ID1");
            StudentDAO std=new StudentDAO();
            Student st=new Student();
            std.searchinfo("id");
        %>
        <h1> <%=st.showStudent()%> </h1>
    </body>
</html>

从studentDAO.java中获取student.java方法“
student1（）”中的空值？StudentDAO.java正确连接了数据库，并分别正确地给出了结果。.但是没有将值作为参数传递给Student.java文件中的“
student1（）”。

阅读 459

2020-06-10

共1个答案

小编典典

更改public void searchinfo(String id2)为public Student searchinfo(String id2)并返回studentinfo [即Student对象]。

// JSP更正

String id = request.getParameter("ID1");
StudentDAO std = new StudentDAO();

Student st = std.searchinfo(id);

2020-06-10