JavaBean 實戰：封裝學生資訊並輸出到 JSP 頁面

Student JavaBean 類別

package com.sp.test;

public class Student {
    private String name;
    private int xuehao;
    private String sex;
    private String banji;

    // Getter / Setter
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public int getXuehao() { return xuehao; }
    public void setXuehao(int xuehao) { this.xuehao = xuehao; }
    public String getSex() { return sex; }
    public void setSex(String sex) { this.sex = sex; }
    public String getBanji() { return banji; }
    public void setBanji(String banji) { this.banji = banji; }

    // 全參建構子
    public Student(String name, int xuehao, String sex, String banji) {
        this.name = name;
        this.xuehao = xuehao;
        this.sex = sex;
        this.banji = banji;
    }

    @Override
    public String toString() {
        return "Student [姓名=" + name + ", 學號=" + xuehao + ", 性別=" + sex + ", 班級=" + banji + "]";
    }
}

JSP 頁面調用

<%@page import="com.sp.test.Student"%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>學生資訊展示</title>
</head>
<body>
    <%
        Student st = new Student("張三", 2016001, "男", "網絡工程");
        out.println(st.toString());
    %>
</body>
</html>

關鍵點

• 屬性私有化，提供公共 Getter/Setter，符合 JavaBean 規範。
• 提供無參建構子（隱式）與全參建構子，方便實例化。
• 覆寫 toString() 便於直接輸出物件資訊。
• JSP 使用 <%@page import%> 導入類別，腳本片段 <% ... %> 建立物件並輸出。