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
/*JSP代码*/
<body>
    This is my JSP page. <br>
     ${param.test2}
     <%=request.getParameter("test2") %>
     ${requestScope.test2}
     <%=request.getAttribute("test2") %>
  </body>
/**
访问网址
http://localhost:8080/Test/TestRequest?test2=3333
后运行结果
*/
This is my JSP page. 
3333 123456 123456

 

也就是说

${param.和<%=request.访问url传递的参数

${requestScope.和<%=request.访问的是servlet传递的参数

 

 KEY：

关键 ${requestScope.*}，是jsp内置对象，和request.getAttribute相似，都是取得现有的后台的数据

 

参考：关于EL表达式中requestScope和param区别

posted on 2014-11-09 20:42  小忙  阅读(2179)  评论(0)  编辑  收藏  举报

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