在Struts2的Action中取得请求参数值的几种方法

先看GetRequestParameterAction类代码：

Java代码

1. publicclassGetRequestParameterActionextendsActionSupport{
3. privateStringbookName;
4. privateStringbookPrice;
6. publicStringgetBookName(){
7. returnbookName;
8. }
10. publicvoidsetBookName(StringbookName){
11. this.bookName=bookName;
12. }
14. publicStringgetBookPrice(){
15. returnbookPrice;
16. }
18. publicvoidsetBookPrice(StringbookPrice){
19. this.bookPrice=bookPrice;
20. }
23. publicStringexecute()throwsException{
26. //方式一：将参数作为Ａction的类属性，让OGNL自动填充
28. System.out.println("方法一，把参数作为Action的类属性,让OGNL自动填充：");
29. System.out.println("bookName:"+this.bookName);
30. System.out.println("bookPrice:"+this.bookPrice);
33. //方法二:在Action中使用ActionContext得到parameterMap获取参数:
34. ActionContextcontext=ActionContext.getContext();
35. MapparameterMap=context.getParameters();
37. StringbookName2[]=(String[])parameterMap.get("bookName");
38. StringbookPrice2[]=(String[])parameterMap.get("bookPrice");
40. System.out.println("方法二，在Action中使用ActionContext得到parameterMap获取参数：");
41. System.out.println("bookName:"+bookName2[0]);
42. System.out.println("bookPrice:"+bookPrice2[0]);
45. //方法三:在Action中取得HttpServletRequest对象，使用request.getParameter获取参数
46. HttpServletRequestrequest=(HttpServletRequest)context.get(ServletActionContext.HTTP_REQUEST);
48. StringbookName=request.getParameter("bookName");
49. StringbookPrice=request.getParameter("bookPrice");
51. System.out.println("方法三，在Action中取得HttpServletRequest对象，使用request.getParameter获取参数：");
52. System.out.println("bookName:"+bookName);
53. System.out.println("bookPrice:"+bookPrice);
54. returnSUCCESS;
56. }
58. }

总结：

• 
  

方法一：当把参数作为Action的类属性，且提供属性的getter/setter方法时，xwork的OGNL会自动把request参数的值设置到类属性中，此时访问请求参数只需要访问类属性即可。 方法二：可以通过ActionContext对象Map parameterMap=context.getParameters();方法，得到请求参数Map，然后通过parameterMap来获取请求参数。需要注意的是：当通过parameterMap的键取得参数值时，取得是一个数组对象，即同名参数的值的集合。 方法三：通过ActionContext取得HttpServletRequest对象，然后使用request.getParameter("参数名")得到参数值。

Struts2中Action接收参数的方法主要有以下三种：
1.使用Action的属性接收参数：
a.定义：在Action类中定义属性，创建get和set方法；
b.接收：通过属性接收参数，如：userName；
c.发送：使用属性名传递参数，如：user1!add?userName=Magci；
2.使用DomainModel接收参数：
a.定义：定义Model类，在Action中定义Model类的对象（不需要new），创建该对象的get和set方法；
b.接收：通过对象的属性接收参数，如：user.getUserName()；
c.发送：使用对象的属性传递参数，如：user2!add?user.userName=MGC；
3.使用ModelDriven接收参数：
a.定义：Action实现ModelDriven泛型接口，定义Model类的对象（必须new），通过getModel方法返回该对象；
b.接收：通过对象的属性接收参数，如：user.getUserName()；
c.发送：直接使用属性名传递参数，如：user2!add?userName=MGC；

实例：

web.xml:

01. <?xmlversion="1.0"encoding="UTF-8"?>

02. <web-appversion="2.5"

03. xmlns="http://java.sun.com/xml/ns/javaee"

04. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

05. xsi:schemaLocation="http://java.sun.com/xml/ns/javaee;

06. http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

07. <welcome-file-list>

08. <welcome-file>hello.jsp</welcome-file>

09. </welcome-file-list>

10. <filter>

11. <filter-name>struts2</filter-name>

12. <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

13. </filter>

14. <filter-mapping>

15. <filter-name>struts2</filter-name>

16. <url-pattern>/*</url-pattern>

17. </filter-mapping>

18. </web-app>

struts.xml:

01. <?xmlversion="1.0"encoding="UTF-8"?>

02. <!DOCTYPEstrutsPUBLIC

03. "-//ApacheSoftwareFoundation//DTDStrutsConfiguration2.0//EN"

04. "http://struts.apache.org/dtds/struts-2.0.dtd">

05.

06. <struts>

07. <!--

08. <constantname="struts.enable.DynamicMethodInvocation"value="false"/>

09. <constantname="struts.devMode"value="false"/>

10.

11. <includefile="example.xml"/>

12.

13.

14.

15. <packagename="default"namespace="/"extends="struts-default">

16. <default-action-refname="index"/>

17. <actionname="index">

18. <resulttype="redirectAction">

19. <paramname="actionName">HelloWorld</param>

20. <paramname="namespace">/example</param>

21. </result>

22. </action>

23. </package>

24. -->

25.

26. <!--Addpackageshere-->

27. <constantname="struts.devMode"value="true"/>

28. <packagename="user"namespace="/"extends="struts-default">

29. <actionname="user*"class="cn.edu.ahau.mgc.struts2.action.UserAction{1}">

30. <result>/addSuccess.jsp</result>

31. </action>

32. </package>

33. </struts>

User.java:

01. packagecn.edu.ahau.mgc.struts2.mode;

02.

03. publicclassUser{

04.

05. privateStringuserName;

06. privateStringpassword;

07.

08. publicStringgetUserName(){

09. returnthis.userName;

10. }

11.

12. publicvoidsetUserName(StringuserName){

13. this.userName=userName;

14. }

15.

16. publicStringgetPassword(){

17. returnthis.password;

18. }

19.

20. publicvoidsetPassword(Stringpassword){

21. this.password=password;

22. }

23. }

UserAction1.java:

01. packagecn.edu.ahau.mgc.struts2.action;

02.

03. importcom.opensymphony.xwork2.ActionSupport;

04.

05. publicclassUserAction1extendsActionSupport{

06.

07. privateStringuserName;

08. privateStringpassword;

09.

10. publicStringadd(){

11. System.out.println("userName:"+userName);

12. System.out.println("password:"+password);

13. returnSUCCESS;

14. }

15.

16. publicStringgetUserName(){

17. returnthis.userName;

18. }

19.

20. publicvoidsetUserName(StringuserName){

21. this.userName=userName;

22. }

23.

24. publicStringgetPassword(){

25. returnthis.password;

26. }

27.

28. publicvoidsetPassword(Stringpassword){

29. this.password=password;

30. }

31. }

UserAction2.java:

01. packagecn.edu.ahau.mgc.struts2.action;

02.

03. importcom.opensymphony.xwork2.ActionSupport;

04.

05. importcn.edu.ahau.mgc.struts2.mode.User;

06.

07. publicclassUserAction2extendsActionSupport{

08.

09. privateUseruser;

10.

11. publicStringadd(){

12. System.out.println("userName:"+user.getUserName());

13. System.out.println("password:"+user.getPassword());

14. returnSUCCESS;

15. }

16.

17. publicUsergetUser(){

18. returnthis.user;

19. }

20.

21. publicvoidsetUser(Useruser){

22. this.user=user;

23. }

24.

25. }

UserAction3.java:

01. packagecn.edu.ahau.mgc.struts2.action;

02.

03. importcn.edu.ahau.mgc.struts2.mode.User;

04.

05. importcom.opensymphony.xwork2.ActionSupport;

06. importcom.opensymphony.xwork2.ModelDriven;

07.

08. publicclassUserAction3extendsActionSupportimplementsModelDriven<User>{

09.

10. privateUseruser=newUser();

11.

12. publicStringadd(){

13. System.out.println("userName:"+user.getUserName());

14. System.out.print("password:"+user.getPassword());

15. returnSUCCESS;

16. }

17.

18. publicUsergetModel(){

19. returnthis.user;

20. }

21.

22. }

index.jsp:

01. <%@pagelanguage="java"import="java.util.*"pageEncoding="GB18030"%>

02. <%

03. Stringpath=request.getContextPath();

04. StringbasePath=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

05. %>

06.

07. <!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN">

08. <html>

09. <head>

10. <basehref="<%=basePath%>">

11.

12. <title>Param</title>

13. <metahttp-equiv="pragma"content="no-cache">

14. <metahttp-equiv="cache-control"content="no-cache">

15. <metahttp-equiv="expires"content="0">

16. <metahttp-equiv="keywords"content="keyword1,keyword2,keyword3">

17. <metahttp-equiv="description"content="Thisismypage">

18. <!--

19. <linkrel="stylesheet"type="text/css"href="styles.css">

20. -->

21. </head>

22.

23. <body>

24. <ahref="user1!add?userName=Magci&password=123456">user1!add?userName=Magci&password=123456</a>

25. <br/>

26. <br/>

27.

28. <ahref="user2!add?user.userName=MGC&user.password=abc">user2!add?user.userName=MGC&user.password=abc</a>

29. <br/>

30. <br/>

31.

32. <ahref="user3!add?userName=MaGC&password=000000">user3!add?userName=MaGC&password=000000</a>

33. </body>

34. </html>

addSuccess.jsp:

01. <%@pagelanguage="java"import="java.util.*"pageEncoding="GB18030"%>

02. <%

03. Stringpath=request.getContextPath();

04. StringbasePath=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

05. %>

06.

07. <!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN">

08. <html>

09. <head>

10. <basehref="<%=basePath%>">

11.

12. <title>AddSuccess</title>

13. <metahttp-equiv="pragma"content="no-cache">

14. <metahttp-equiv="cache-control"content="no-cache">

15. <metahttp-equiv="expires"content="0">

16. <metahttp-equiv="keywords"content="keyword1,keyword2,keyword3">

17. <metahttp-equiv="description"content="Thisismypage">

18. <!--

19. <linkrel="stylesheet"type="text/css"href="styles.css">

20. -->

21. </head>

22.

23. <body>

24. UserAddSuccess!<br>

25. </body>

26. </html>