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  • JSP JavaBeans

    Javabean的设计原则

    • 公有类
    • 无参公有构造方法
    • 私有属性
    • getter和setter方法

    在Jsp页面中如何使用Javabeans?

      像使用普通Java类一样,创建JavaBeans实例。

      在JSP页面中通常使用JSP动作标签使用JavaBeans。

        useBeans动作

        setProperty动作

        getProperty动作

    示例代码:

    package com.po;
    
    
    /**
     * 用户类
     */
    public class Users {
        private String username;
        private String password;
    
        public Users(){
    
        }
    
        public String getUsername() {
            return username;
        }
    
        public void setUsername(String username) {
            this.username = username;
        }
    
        public String getPassword() {
            return password;
        }
    
        public void setPassword(String password) {
            this.password = password;
        }
    }
    JavaBeans
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>Login Demo</title>
    </head>
    <body>
        <h1>系统登录</h1>
        <hr>
        <form name="loginForm" action="do_login.jsp?myPass=888888&myUser=Vincent" method="post">
            <table>
                <tr>
                    <td>Username:</td>
                    <td><input type="text" name="username" value="" placeholder="username" /></td>
                </tr>
                <tr>
                    <td>Password:</td>
                    <td><input type="password" name="password" value="" placeholder="password" /></td>
                </tr>
                <tr>
                    <td colspan="2" align="center"><input type="submit" value="Login"/></td>
                </tr>
            </table>
        </form>
    </body>
    </html>
    HTML-Login.jsp
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>DoLogin Demo</title>
    </head>
    <body>
        <jsp:useBean id="myUsers" class="com.po.Users" scope="page" />
        <h1>setProperty动作元素</h1>
        <hr>
        <!-- 根据表单自动匹配所有的属性 -->
        <jsp:setProperty name="myUsers" property="*" />
        Username: <%=myUsers.getUsername()%><br>
        Password: <%=myUsers.getPassword()%><br>
    
        <!-- 根据表单匹配所有部分的属性 -->
        <jsp:setProperty name="myUsers" property="username" />
        <jsp:setProperty name="myUsers" property="password" />
        Username: <%=myUsers.getUsername()%><br>
        Password: <%=myUsers.getPassword()%><br>
    
        <!-- 跟表单无关,通过手工赋值给属性 -->
        <jsp:setProperty name="myUsers" property="username" value="Menroe" />
        <jsp:setProperty name="myUsers" property="password" value="123456" />
        Username: <%=myUsers.getUsername()%><br>
        Password: <%=myUsers.getPassword()%><br>
    
        <!-- 通过Request获取参数属性 -->
        <jsp:setProperty name="myUsers" property="username" param="myUser" />
        <jsp:setProperty name="myUsers" property="password" param="myPass" />
        Username: <%=myUsers.getUsername()%><br>
        Password: <%=myUsers.getPassword()%><br>
    </body>
    </html>
    HTML-doLogin.jsp
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  • 原文地址:https://www.cnblogs.com/vincenshen/p/10225972.html
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