javaweb入门

jsp3种脚本语言

<%//局部变量
    out.println("hello World"+"
");
    init("chenwei");
%>
<%!//全局变量，定义方法
    String name ;
    public void init(String name){
        this.name = name;
    }
%>

<%="hello"+ name %>

jsp九大内置对象

1、response：处理页面的请求 登录简单实现：
register.jsp

    

    name:

    password:

    age:

    hobbies:

    篮球

    足球

    台球

    
    
    

show.jsp

注册成功，信息如下：
<%
        request.setCharacterEncoding("utf-8");
    String name = request.getParameter("uname");
    String pass = request.getParameter("upass");
    int age = Integer.parseInt(request.getParameter("uname"));
    String[] hobbies = request.getParameterValues("hobbies");
%>
name:<%=name %>

pass:<%=pass %>

age:<%=age %>

hobbies:

<%
    if(hobbies!=null){
        for( String hobby:hobbies){
            out.print(hobby+" ");
        }
                
    }

%>

2.请求转发和重定向

request.setCharacterEncoding("utf-8");
String name = request.getParameter("uname");
String pwd = request.getParameter("upwd");
if(name.equals("cwi")&& pwd.equals("123")){
    //重定向：2次请求 不携带数据 浏览器地址栏不改变
    //response.sendRedirect("info.jsp");
    //请求转发：1次请求 携带数据 浏览器地址栏改变
    request.getRequestDispatcher("info.jsp").forward(request, response);
}else{
    out.print("login fail");
}

3.Cookie的简单使用

//服务端
<%
Cookie cookie1 = new Cookie("name","zs");
Cookie cookie2 = new Cookie("pwd","123");
response.addCookie(cookie1);
response.addCookie(cookie2);
response.sendRedirect("result.jsp");
%>

//客户端
Cookie[] cookies = request.getCookies();
for (Cookie cookie:cookies){
    out.print(cookie.getName()+"--"+cookie.getValue()+"
");
}