[英]Convert JSP java code
I have a web application, I'm using JSP, so when I insert java code I start opening it as <%%>
but I want to use <%!%>
how can I do it? 我有一个Web应用程序,我正在使用JSP,所以当我插入Java代码时,我开始以
<%%>
打开它,但是我想使用<%!%>
怎么做?
There is my code: 有我的代码:
<body>
<h1>Factorial</h1>
<form action="" method=post>
<input type="number" name="cantidad" min="1">
<input type= "submit" value=submit>
</form>
<%
String numero=request.getParameter("cantidad");
if(numero != null){
Integer num = Integer.parseInt(request.getParameter("cantidad"));
if(num != null){
int res =1;
for (int s=1; s <=num; s++){
res *=s;
}
out.print(res);
}
}
%>
</body>
So, how can I do that? 那么,我该怎么做呢?
The <%! %>
<%! %>
<%! %>
is for JSP Declarations . <%! %>
用于JSP声明 。
The linked Java 5 EE Tutorial says (in part) 链接的Java 5 EE教程说(部分)
A JSP declaration is used to declare variables and methods in a page's scripting language.
JSP声明用于以页面的脚本语言声明变量和方法。
So you'd need to declare something 所以你需要声明一些东西
<%!
static final int getANumber() {
return 101;
}
%>
then you can call that function in a scriptlet. 那么您可以在脚本中调用该函数。 But you really should prefer to use a more modern Java web technology (and avoid scriptlets).
但是您确实应该更喜欢使用更现代的Java Web技术(并避免使用scriptlet)。
All JSP files will be converted into Servlet (.java and finally .class) files by the Application server. 应用程序服务器将所有JSP文件转换为Servlet(.java,最后是.class)文件。
JSP Declarations: JSP声明:
<%!
<%! int count = 0;
int count = 0; %> ===> Declares 'count' Instance Variable inside the Servlet Class generated by the Server, this variable is common for all requests, usage of this is discouraged, unless there is a strong reason.
%> ===>在服务器生成的Servlet类中声明“ count”实例变量,该变量对于所有请求都是通用的,除非有充分的理由,否则不鼓励使用此变量。
Scriptlets: 小脚本:
<% int count =0;
<%int count = 0; %> ===> Declares Local Variable inside service() method, this variable is local for each request, so there is no problem of usage.
%> ===>在service()方法内声明局部变量,该变量对于每个请求都是局部的,因此没有使用问题。 However, scriptles inside JSP are generally considered as bad practice.
但是,JSP中的脚本通常被认为是不好的做法。
<℅!℅>,仅用于变量和方法声明。
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