Java JSP scriptlet 中的方法是否合法？
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Are methods legal inside JSP scriptlet?
提问by bba
I know its not recommended, and I should be using tag libraries etc etc.
我知道它不推荐，我应该使用标签库等。
But I'd still like to know if it is legal to declare methods in a JSP scriplet:
但我还是想知道在 JSP 脚本中声明方法是否合法：
<%
public String doSomething(String param) {
//
}
String test = doSomething("test");
%>
Is that legal? I am getting some weird compile errors (like a ; is expected) that don't seem to fit. Thanks.
这是合法的吗？我收到了一些a ; is expected似乎不合适的奇怪编译错误（如）。谢谢。
采纳答案by axtavt
You need to use declaration syntax (<%! ... %>):
您需要使用声明语法 ( <%! ... %>)：
<%!
public String doSomething(String param) {
//
}
%>
<%
String test = doSomething("test");
%>
回答by Saurabh Jain
Understand the working of jsp:The entire JSP is converted to a Java class by Tomcat. This Java class is nothing but the Servlet. So it is the servlet that you will be running at the end.
理解jsp的工作原理：整个JSP被Tomcat转换成Java类。这个 Java 类不过是 Servlet。因此，您将在最后运行 servlet。
Now considerthat you are writing a Jsp code that prints the sum of 2 nos,passed in a method
现在考虑您正在编写一个 Jsp 代码，该代码打印 2 个 nos 的总和，并在方法中传递
<body>
<%!
public int add(int a,int b)
{
return a+b;
}
%>
<%
int k;
k=add(5,6);
%>
<%=
k
%>
</body>
So if you were to write the same code that prints out sum of 2 nos in a servlet, you would probably write that in doGet() method.
因此，如果您要编写在 servlet 中打印出 2 个 nos 之和的相同代码，您可能会在 doGet() 方法中编写它。
The reasonwhy you would get an error is you are defining a method within another method (which violates the rule of method definitions).
你会得到错误的原因是你在另一个方法中定义了一个方法（这违反了方法定义的规则）。
Hence we put the method in the definition tag so that if forms a new method
因此我们将方法放在定义标签中，以便 if 形成一个新方法
