将自定义对象从servlet传递到JSP

Ash*_*Ash 6 session jsp

我想将一个类型为Student的自定义对象从servlet传递给JSP.我创建了一个Student bean类.学生包含2个属性firstname和lastName.

学生豆:

import java.io.Serializable;

public class Student implements Serializable {

    public Student() {
    }

    String firstName;
    String lastName;

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

}
Run Code Online (Sandbox Code Playgroud)

用于从用户获取FirstName和LastName的HTML文件:

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
    <form id="myForm" method="POST" action="MyFormServlet">
        FirstName<input type="text" id="firstName"  name="FirstName"/><br>
        LastName<input type="text" id="lastName" name="LastName"/><br>
        <button type="submit" />Submit</button>
    </form>
</body>
</html>
Run Code Online (Sandbox Code Playgroud)

Servlet代码:

import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;



    public class MyFormServlet extends HttpServlet {

        @Override
        protected void doPost(HttpServletRequest request,
                HttpServletResponse response) {

            Student s = new Student();
            s.setFirstName(request.getParameter("FirstName"));
            s.setLastName(request.getParameter("LastName"));

            HttpSession session =request.getSession();
            session.setAttribute("student", s);

            try {
                RequestDispatcher rd = getServletContext().getRequestDispatcher("/myJsp.jsp");
                rd.forward(request, response);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }
Run Code Online (Sandbox Code Playgroud)

myJsp.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
    <body>
        <%
            // I want to do something like this :   
            //Student student =(Student)session.getAttribute("student");
            //String fullName=student.firstName + student.lastName;
        %>      
        <h1><%=fullName%></h1>
    </body>
</html>
Run Code Online (Sandbox Code Playgroud)

我想获取'student'对象,访问其属性并将其存储在JSP变量中以进行进一步处理.

Bal*_*usC 10

setAttribute()对方法request,sessionservletContext已经将使其可作为JSP/EL由属性名称变量.

在您的特定情况下,使用servlet中的以下行,

session.setAttribute("student", s);
Run Code Online (Sandbox Code Playgroud)

它在JSP/EL中可用${student}.所以,这应该做:

<body>
    <h1>${student.firstName} ${student.lastName}</h1>
</body>
Run Code Online (Sandbox Code Playgroud)

如果要将其作为JSP中的另一个变量存储,以便可以多次重复使用它,请使用JSTL <c:set>.

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
...
<body>
    <c:set var="fullName" value="${student.firstName} ${student.lastName}" />
    <h1>${fullName}</h1>
</body>
Run Code Online (Sandbox Code Playgroud)


Har*_*hra 3

如果不需要在整个会话中使用,您应该将属性传递到请求范围。在Servlet中,

 request.setAttribute("student", s);
Run Code Online (Sandbox Code Playgroud)

在 JSP 中,

Student student =(Student) request.getAttribute("student");
String fullName = "Default";
if(student!=null){
 fullName=student.firstName +" " + student.lastName;
}
Run Code Online (Sandbox Code Playgroud)