Struts2中訪問web元素

　　取得Map類型requestsessionapplication真實類型 HttpServletRequest HttpSession ServletContext的引用:

　　前三者依賴於容器

　　前三者IOC (只用這種)

　　後三者依賴於容器

　　後三者IOC

　　一方法一ActionContext方式

　　一般在Action類的構造方法或execute()方法中獲取

　　[java]

　　public class LoginAction extends ActionSupport {

　　private Map request;

　　private Map session;

　　private Map application;

　　public LoginAction() {

　　request = (Map)ActionContextgetContext()get(request);

　　session = ActionContextgetContext()getSession();

　　application = ActionContextgetContext()getApplication();

　　}

　　public String execute() {

　　requestput(r r);

　　sessionput(s s);

　　applicationput(a a);

　　return SUCCESS;

　　}

　　public class LoginAction extends ActionSupport {

　　private Map request;

　　private Map session;

　　private Map application;

　　public LoginAction() {

　　request = (Map)ActionContextgetContext()get(request);

　　session = ActionContextgetContext()getSession();

　　application = ActionContextgetContext()getApplication();

　　}

　　public String execute() {

　　requestput(r r);

　　sessionput(s s);

　　applicationput(a a);

　　return SUCCESS;

　　}

　　然後在Jsp頁面中獲取相關web元素

　　[html]

<body>

　　User Login Success!

<s:property value=#requestr/> | <%=requestgetAttribute(r) %>

<s:property value=#sessions/> | <%=sessiongetAttribute(s) %>

<s:property value=#applicationa/> | <%=applicationgetAttribute(a) %>

<s:property value=#attra/>

<s:property value=#attrs/>

<s:property value=#attrr/>

<s:debug></s:debug>

</body>

<body>

　　User Login Success!

<s:property value=#requestr/> | <%=requestgetAttribute(r) %>

<s:property value=#sessions/> | <%=sessiongetAttribute(s) %>

<s:property value=#applicationa/> | <%=applicationgetAttribute(a) %>

<s:property value=#attra/>

<s:property value=#attrs/>

<s:property value=#attrr/>

<s:debug></s:debug>

</body>

　　注因為requestsessionapplication對象Struts將在放入到Action Context中

　　因此需要使用#key來訪問對象們

　　後面的是java腳本代碼的訪問方式

　　一方式二Ioc(控制反轉)—推薦使用

　　讓Action類實現RequestAwareSessionAwareApplicationAware接口然後重寫他們的set方法(setRequestsetSessionsetApplication)通過依賴注入控制反轉(原來自己控制現在由別人來控制值)

　　[java]

　　import orgapachestrutsinterceptorApplicationAware;

　　import orgapachestrutsinterceptorRequestAware;

　　import orgapachestrutsinterceptorSessionAware;

　　import comopensymphonyxworkActionSupport;

　　public class LoginAction extends ActionSupport implements RequestAwareSessionAware ApplicationAware {

private Map<String Object> request;

private Map<String Object> session;

private Map<String Object> application;

　　//DI dependency injection依賴注入

　　//IoC inverse of control控制反轉

　　public String execute() {

　　requestput(r r);

　　sessionput(s s);

　　applicationput(a a);

　　return SUCCESS;

　　}

　　@Override

public void setRequest(Map<String Object> request) {

　　thisrequest = request;

　　}

　　@Override

public void setSession(Map<String Object> session) {

　　thissession = session;

　　}

　　@Override

public void setApplication(Map<String Object> application) {

　　thisapplication = application;

　　}

　　import orgapachestrutsinterceptorApplicationAware;

　　import orgapachestrutsinterceptorRequestAware;

　　import orgapachestrutsinterceptorSessionAware;

　　import comopensymphonyxworkActionSupport;

　　public class LoginAction extends ActionSupport implements RequestAwareSessionAware ApplicationAware {

private Map<String Object> request;

private Map<String Object> session;

private Map<String Object> application;

　　//DI dependency injection依賴注入

　　//IoC inverse of control控制反轉

　　public String execute() {

　　requestput(r r);

　　sessionput(s s);

　　applicationput(a a);

　　return SUCCESS;

　　}

　　@Override

public void setRequest(Map<String Object> request) {

　　thisrequest = request;

　　}

　　@Override

public void setSession(Map<String Object> session) {

　　thissession = session;

　　}

　　@Override

public void setApplication(Map<String Object> application) {

　　thisapplication = application;

　　}

　　在視圖(JSP)頁面中獲取相關對象同方式一

　　一方式三獲取原類型

　　獲取是的HttpServletRequest/HttpSession/ServletContext

　　[java]

　　public class LoginAction extends ActionSupport {

　　private HttpServletRequest request;

　　private HttpSession session;

　　private ServletContext application;

　　public LoginAction() {

　　request = ServletActionContextgetRequest();

　　session = requestgetSession();

　　application = sessiongetServletContext();

　　}

　　public String execute() {

　　requestsetAttribute(r r);

　　sessionsetAttribute(s s);

　　applicationsetAttribute(a a);

　　return SUCCESS;

　　}

　　public class LoginAction extends ActionSupport {

　　private HttpServletRequest request;

　　private HttpSession session;

　　private ServletContext application;

　　public LoginAction() {

　　request = ServletActionContextgetRequest();

　　session = requestgetSession();

　　application = sessiongetServletContext();

　　}

　　public String execute() {

　　requestsetAttribute(r r);

　　sessionsetAttribute(s s);

　　applicationsetAttribute(a a);

　　return SUCCESS;

　　}

　　一方式四獲取原類型控制反轉

　　首先需要Action實現orgapachestrutsinterceptorServletRequestAware接口然後重寫setServletRequest()方法獲取HttpServletRequest對象再通過HttpServletRequest對象取昨HttpSession和ServletContext對象

　　[java]

　　import javaxservletServletContext;

　　import javaxservlethttpHttpServletRequest;

　　import javaxservlethttpHttpSession;

　　import orgapachestrutsinterceptorServletRequestAware;

　　import comopensymphonyxworkActionSupport;

　　public class LoginAction extends ActionSupport implements ServletRequestAware {

　　private HttpServletRequest request;

　　private HttpSession session;

　　private ServletContext application;

　　public String execute() {

　　requestsetAttribute(r r);

　　sessionsetAttribute(s s);

　　applicationsetAttribute(a a);

　　return SUCCESS;

　　}

　　@Override

　　public void setServletRequest(HttpServletRequest request) {

　　thisrequest = request;

　　thissession = requestgetSession();

　　thisapplication = sessiongetServletContext();

　　}

　　import javaxservletServletContext;

　　import javaxservlethttpHttpServletRequest;

　　import javaxservlethttpHttpSession;

　　import orgapachestrutsinterceptorServletRequestAware;

　　import comopensymphonyxworkActionSupport;

　　public class LoginAction extends ActionSupport implements ServletRequestAware {

　　private HttpServletRequest request;

　　private HttpSession session;

　　private ServletContext application;

　　public String execute() {

　　requestsetAttribute(r r);

　　sessionsetAttribute(s s);

　　applicationsetAttribute(a a);

　　return SUCCESS;

　　}

　　@Override

　　public void setServletRequest(HttpServletRequest request) {

　　thisrequest = request;

　　thissession = requestgetSession();

　　thisapplication = sessiongetServletContext();

　　}

From:http://tw.wingwit.com/Article/program/Java/ky/201311/28170.html