JSP参数传递兼EL表达式

 1.浏览器?方式传递参数

/**
浏览器地址栏输入?方式传递参数
?test=123
*/
可以用${param.test}方式输出

 2.页面内部设置参数setAttribute

/**
JSP页面中输入
<% request.setAttribute("test2", "1234");%>
传递参数
*/
可以在页面代码中输入以下方式输出：
${requestScope.test2}
<%=request.getAttribute("test2") %>

 3.servlet设置request参数的访问：

 

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestRequest extends HttpServlet{                
    void  TestRequest(){
    }
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        String test2=new String("aaaaa");
        request.setAttribute("test2", test2);
        
         RequestDispatcher dispatch = request.getRequestDispatcher("/index.jsp");    /*设置跳转页面*/
         dispatch.forward(request, response);                                        /*转发request数据到目标页*/
        }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException { 
            doGet(request, response);
        }
}

servlet代码