Struts2中action获取request、response、session的方式

第一种方式，非IoC(Spring中的控制反转)方式：

1. package com.action;
2. import java.util.Map;
3. import javax.servlet.http.HttpServletRequest;
4. import javax.servlet.http.HttpServletResponse;
5. import org.apache.struts2.ServletActionContext;
6. import com.opensymphony.xwork2.ActionContext;
7. import com.opensymphony.xwork2.ActionSupport;
8. 
   
9. public class BaseAction extends ActionSupport {
10. private static final long serialVersionUID = 7620009925942346125L;
12. ActionContext context = ActionContext.getContext();
13. HttpServletRequest request = (HttpServletRequest) context.get(ServletActionContext.HTTP_REQUEST);
14. HttpServletResponse response = (HttpServletResponse) context.get(ServletActionContext.HTTP_RESPONSE);
15. Map session = context.getSession();
16. //SessionMap session = (SessionMap) context.get(ActionContext.SESSION);
18. }

咱们日常所说的session通常是HttpSession，但在struts2中被封装成了Map类型。

第二种方式，IoC方式：

1. package com.action;
2. import java.util.Map;
3. import javax.servlet.http.HttpServletRequest;
4. import javax.servlet.http.HttpServletResponse;
5. import org.apache.struts2.dispatcher.SessionMap;
6. import org.apache.struts2.interceptor.ServletRequestAware;
7. import org.apache.struts2.interceptor.ServletResponseAware;
8. import org.apache.struts2.interceptor.SessionAware;
9. import com.opensymphony.xwork2.ActionContext;
10. import com.opensymphony.xwork2.ActionSupport;
11. 
    
12. public class BaseAction extends ActionSupport implements SessionAware, ServletRequestAware, ServletResponseAware {
13. private static final long serialVersionUID = 7620009925942346125L;
15. ActionContext context = ActionContext.getContext();
16. HttpServletRequest request;
17. HttpServletResponse response;
18. SessionMap session;
20. //获取request,response,session方式一，非IoC方式，不用实现SessionAware, ServletRequestAware, ServletResponseAware
21. //ActionContext context = ActionContext.getContext();
22. //HttpServletRequest request = (HttpServletRequest) context.get(ServletActionContext.HTTP_REQUEST);
23. //HttpServletResponse response = (HttpServletResponse) context.get(ServletActionContext.HTTP_RESPONSE);
24. //Map session = context.getSession();
25. //SessionMap session = (SessionMap) context.get(ActionContext.SESSION);
27. //获取request,response,session方式一，IoC方式，必须实现SessionAware, ServletRequestAware, ServletResponseAware
28. public void setSession(Map map) {
29. this.session = (SessionMap) map;
30. }
31. public void setServletRequest(HttpServletRequest request) {
32. this.request = request;
33. }
34. public void setServletResponse(HttpServletResponse response) {
35. this.response = response;
36. }
38. }

这样咱们在写action时直接继承这个BaseAction，那些request、response、session之类就能够正常地用了，good。等我下午有时间反编译一下别人封装好的BaseAction，看看是否是这样搞的，哈哈。

ps：
平时咱们在action中要把值设进session而后在jsp页面去的话，通常是这样(struts2不行)：

1. public String findAllUsers() throws Exception {
3. List<User> userList = userService.findAllUsers();
5. HttpSession se = request.getSession();
6. se.setAttribute("userList", userList);
8. session.put("userList", userList);
9. //session.put("aaa", "bbb");
10. //session.put(key, value);
12. //request.setAttribute("userList", userList);
14. return SUCCESS;
15. }

在struts2中，设进session的话则应该变成这样了，由于session是一个map类型：

1. public String findAllUsers() throws Exception {
3. List<User> userList = userService.findAllUsers();
4. session.put("userList", userList);
5. //request.setAttribute("userList", userList);
7. return SUCCESS;
8. }

听说，若是直接到jsp页面的话，通常推荐用request而不用session，多人单机同时操做的话保险一点，虽然一个浏览器同一时间只有一个session。

在jsp页面取值的话：

1. <table class="table_report">
2. <tr>
3. <th>用户ID</th>
4. <th>用户名称</th>
5. <th>用户性别</th>
6. <th>用户年龄</th>
7. <th>用户地址</th>
8. <th>用户电话</th>
9. <th>用户邮箱</th>
10. </tr>
11. <!-- struts2最正规的取值方式 -->
12. <%-- <s:iterator id="user" value="%{#session.userList}">--%>
13. <s:iterator id="user" value="#session.userList">
14. <%-- <s:iterator id="user" value="#request.userList">--%>
15. <tr>
16. <td>${user.id}</td>
17. <td>${user.name}</td>
18. <td>${user.sex}</td>
19. <td>${user.age}</td>
20. <td>${user.address}</td>
21. <td>${user.phone}</td>
22. <td>${user.email}</td>
23. </tr>
24. </s:iterator>
25. </table>
26. <%-- 用完要清空 --%>
27. <%request.removeAttribute("userList");%>
28. <%--<%session.removeAttribute("userList");%>--%>