当我们查询数据的时候，把它存放到一个位置。以供页面显示。
1：使用***Map取代内置对象存放
public String query(){ ActionContext.getContext().put("categoryList", categoryService.query()); ActionContext.getContext().getSession().put("categoryList", categoryService.query()); ActionContext.getContext().getApplication().put("categoryList", categoryService.query()); return "index"; }
对应的页面的显示
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP 'index.jsp' starting page</title> </head> <body> <a href="${pageContext.request.contextPath }/category_update.action">访问update</a> <a href="category_query.action">查询所有类别</a><br/> <c:forEach items="${requestScope.categoryList}" var="category"> ${category.id }|${category.type }|${category.hot}<br/> </c:forEach><br/> <c:forEach items="${sessionScope.categoryList}" var="gory"> ${gory.id }|${gory.type }|${gory.hot}<br/> </c:forEach><br/> <c:forEach items="${applicationScope.categoryList}" var="category"> ${category.id }|${category.type }|${category.hot}<br/> </c:forEach><br/> </body> </html>
方案2：
利用接口implements RequestAware,ApplicationAware,SessionAware
package lw.shop.action; import java.util.Map; import org.apache.struts2.interceptor.ApplicationAware; import org.apache.struts2.interceptor.RequestAware; import org.apache.struts2.interceptor.SessionAware; import com.opensymphony.xwork2.ActionSupport; public class BaseAction extends ActionSupport implements RequestAware,ApplicationAware,SessionAware{ protected Map<String,Object> request; protected Map<String,Object> session; protected Map<String,Object> application; @Override public void setSession(Map<String, Object> session) { this.session=session; } @Override public void setApplication(Map<String, Object> application) { this.application=application; } @Override public void setRequest(Map<String, Object> request) { this.request=request; } }
然后Action继承BaseAction就可以了。