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); } }
/*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