我们有时需要在jsp页面中获取request中的参数，然后根据这些参数决定页面的一些内容或者动作。通常我们通过equest.getParameter(xxx);来获取，除了这种方式外，我们还可以通过param或者js来实现。
通过EL中的param
EL中有很多内置对象，我们使用param就可以获取参数
JSP EL Implicit Objects:
The JSP expression language supports the following implicit objects:
Implicit object Description
pageScope Scoped variables from page scope
requestScope Scoped variables from request scope
sessionScope Scoped variables from session scope
applicationScope Scoped variables from application scope
param Request parameters as strings
paramValues Request parameters as collections of strings
header HTTP request headers as strings
headerValues HTTP request headers as collections of strings
initParam Context-initialization parameters
cookie Cookie values
pageContext The JSP PageContext object for the current page
//do something
或者你在js中这样
Name is
Name is <%=appName%>