在Form提交后的变量，很多情况是要展现在jsp页面中，这时Action到Render的变量传递就非常有用。
例如，您在数据库中添加了学生的详细信息。
为了实现这一需求，先创建Form表单（学生的细节，如姓名、出生日期等，通过action url来实现）。
当用户提交表单时，这些数据（学生信息）会在你执行CRUD操作的action方法添加。
添加完成后，需要把一些信息展现到jsp页面。
和v6.2不同的是，action方法里不需要写类似这样的语句：
actionResponse.setRenderParameter("XXX", 变量名);
actionRequest.setAttribute("XXX", 变量名);
举例说明
在Action阶段，我们提交了name变量，然后需要在Render阶段展现在JSP
Java代码
package com.lifiti.portlet; import com.liferay.portal.kernel.log.Log; import com.liferay.portal.kernel.log.LogFactoryUtil; import com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet; import com.liferay.portal.kernel.util.ParamUtil; import java.io.IOException; import java.util.ArrayList; import java.util.List; import javax.portlet.ActionRequest; import javax.portlet.ActionResponse; import javax.portlet.Portlet; import javax.portlet.PortletException; import javax.portlet.ProcessAction; import javax.portlet.RenderRequest; import javax.portlet.RenderResponse; import org.osgi.service.component.annotations.Component; @Component(immediate = true, property = { "com.liferay.portlet.display-category=category.sample", "com.liferay.portlet.instanceable=true", "javax.portlet.requires-namespaced-parameters=false", "javax.portlet.display-name=com.lifiti.parts Portlet", "javax.portlet.init-param.template-path=/", "javax.portlet.init-param.view-template=/view.jsp", "javax.portlet.resource-bundle=content.Language", "javax.portlet.security-role-ref=power-user,user" }, service = Portlet.class) public class FirstPortlet extends MVCPortlet { private static final Log _log = LogFactoryUtil.getLog(FirstPortlet.class.getName()); @Override public void render(RenderRequest request, RenderResponse response) throws PortletException, IOException { String peopleName = ParamUtil.get(request, "name", ""); String age = ParamUtil.get(request, "age", ""); _log.info("peopleName by ParamUtil in render ==>" + peopleName); _log.info("age by ParamUtil in render ==>" + age); _log.info("age By RenderParameter in render ==>" + request.getAttribute("ageBySetParameter")); request.setAttribute("peopleName", peopleName); super.render(request, response); } @ProcessAction(name = "send") public void ReceiveData(ActionRequest actionRequest, ActionResponse actionResponse) throws Exception { String name = ParamUtil.getString(actionRequest, "name"); String age = ParamUtil.getString(actionRequest, "age"); String phone = ParamUtil.getString(actionRequest, "phone"); actionRequest.setAttribute("phone", phone); //actionResponse.setRenderParameter("ageBySetParameter", age); List<String> list = new ArrayList<String>(); list.add("tom"); list.add("cat"); list.add("ketty"); actionRequest.setAttribute("personList", list); _log.info(" 开始接收数据"); System.out.println("FirstPortlet.java name = " + name); System.out.println("FirstPortlet.java age = " + age); System.out.println("FirstPortlet.java phone = " + phone); } }
jsp
<%@page import="com.liferay.portal.kernel.portlet.LiferayPortletMode"%> <%@page import="com.liferay.portal.kernel.portlet.LiferayWindowState"%> <%@ include file="/init.jsp" %> <p> <b><liferay-ui:message key="com_lifiti_parts_ComLifitiPartsmvcportlet.caption"/></b> </p> <c:set var="submit"><liferay-ui:message key="com_lifiti_parts_ComLifitiPartsmvcportlet.submit"/></c:set> <c:if test="${not empty phone }"> Phone: ${phone} added successfully. </c:if> <c:if test="${not empty peopleName }"> PeopleName: ${peopleName} added successfully. </c:if> <c:forEach var="x" items="${personList}">
<br> ${x}<br>
</c:forEach> <portlet:actionURL var="sendURL" name="send"> </portlet:actionURL> <form action="${sendURL}" method="post" name="fm"> <aui:input name="name" label="Name" id="name"/> <aui:input name="age" label="Age" id="age"/> <input type="text" name="<portlet:namespace/>phone" /> <input type="submit" value="${submit}"></input> </form>
log：
FirstPortlet.java name = 王昕
FirstPortlet.java age = 1
FirstPortlet.java phone = 123
16:16:59,946 INFO [http-nio-8080-exec-7][FirstPortlet:32] peopleName by ParamUtil in render ==>王昕
16:16:59,947 INFO [http-nio-8080-exec-7][FirstPortlet:33] age by ParamUtil in render ==>1
16:16:59,947 INFO [http-nio-8080-exec-7][FirstPortlet:34] age By RenderParameter in render ==>null
v7.0中这种语句可以不用写：
actionRequest.setAttribute("phone", phone);
actionResponse.setRenderParameter("ageBySetParameter", age);
实际上，只需要2句就能完成数值传递：
String peopleName = ParamUtil.get(request, "name", "");
request.setAttribute("peopleName", peopleName);
直接使用ParamUtil很方便