有两种方式可以实现在Action中使用Servlet的API。一种是使用org.apache.struts2.ServletActionContext类，另一种是使用com.opensymphony.xwork2.ActionContext类。
struts2推荐的是使用第二种方式：使用ActionContext类来对request、session和application对象进行操作。
方式一：使用ServletActionContext类（紧耦合）
1. 创建控制层
package com.clzhang.struts2.demo4;
import org.apache.struts2.ServletActionContext;
public class ServletActionContextTestAction {
private String usernameRequest;
private String usernameSession;
private String usernameApplication;
public String getUsernameApplication() {
return usernameApplication;
}
public String getUsernameRequest() {
return usernameRequest;
}
public void setUsernameRequest(String usernameRequest) {
this.usernameRequest = usernameRequest;
}
public String getUsernameSession() {
return usernameSession;
}
public void setUsernameSession(String usernameSession) {
this.usernameSession = usernameSession;
}
public void setUsernameApplication(String usernameApplication) {
this.usernameApplication = usernameApplication;
}
public String execute() {
usernameRequest = "request级别的用户名：张三";
usernameSession = "session级别的用户名：李四";
usernameApplication = "application级别的用户名：赵五";
ServletActionContext.getRequest().setAttribute("usernameRequest",
usernameRequest);
ServletActionContext.getRequest().getSession().setAttribute(
"usernameSession", usernameSession);
ServletActionContext.getServletContext().setAttribute(
"usernameApplication", usernameApplication);
return "showResult";
}
}
2. 修改配置文件struts.xml
<action name="servletActionContextTest" class="com.clzhang.struts2.demo4.ServletActionContextTestAction">
<result name="showResult">/struts2/demo4/showResult.jsp</result>
</action>
3. 创建显示JSP文件（showResult.jsp）
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page isELIgnored="false"%>
<%@ taglib uri="/struts-tags" prefix="s"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
#request.usernameRequest值是：
<s:property value="#request.usernameRequest" />
<br />
#session.usernameSession值是：
<s:property value="#session.usernameSession" />
<br />
#application.usernameApplication值是：
<s:property value="#application.usernameApplication" />
<br />
</body>
</html>
4. 测试
打开IE，输入地址：http://127.0.0.1:8080/st/struts2/servletActionContextTest.action
结果如下：
方式二：使用ActionContext类（松耦合）
1. 创建控制层
package com.clzhang.struts2.demo4;
import java.util.Map;
import com.opensymphony.xwork2.ActionContext;
public class ActionContextTestAction {
public String execute() {
// 第一种方法向request对象中放数据
// 因为ActionContext类没有getRequest()这样的方法，所以需要使用下面的方式获取request对象
Map request = (Map) ActionContext.getContext().get("request");
request.put("requestValue", "this is reqeustValue");
// 第二种方法向request对象中放数据
ActionContext.getContext().put("otherrequest",
"this is otherrequest value");
Map session = (Map) ActionContext.getContext().getSession();
session.put("sessionValue", "this is sessionValue");
Map application = (Map) ActionContext.getContext().getApplication();
application.put("applicationValue", "this is applicationValue");
return "showScopeValue";
}
}
2. 修改配置文件struts.xml
<action name="actionContextTest" class="com.clzhang.struts2.demo4.ActionContextTestAction">
<result name="showScopeValue">/struts2/demo4/showScopeValue.jsp</result>
</action>
3. 创建显示JSP文件（showScopeValue.jsp）
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
request:
<s:property value="#request.requestValue" />
<br />
<br />
otherrequest:
<s:property value="#request.otherrequest" />
<br />
<br />
session:
<s:property value="#session.sessionValue" />
<br />
<br />
application:
<s:property value="#application.applicationValue" />
<br />
<br />
</body>
</html>
4. 测试
打开IE，输入地址：http://127.0.0.1:8080/st/struts2/actionContextTest.action
结果如下：