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技術社區[雲棲]
Struts2中操作request,session,application的方法
Map類型——request,session,application
真實類型——HttpServletRequest,HttpSession,ServletContext
Map類型是Struts對真實類型的一個封裝，會將真實類型映射到Map類型中
取得上述元素有以下4種方法
1 通過ActionContext來訪問request,session,application對象
2 通過實現RequestAware、SessionAware、ApplicationAware接口來訪問request,session,application對象(常用)
3 通過ServletActionContext來訪問request,session,application對象
4 通過實現ServletRequestAware接口來訪問request,session,application對象
馬士兵老師對這裏的內容講得非常詳細，結合馬士兵老師的源碼來看一下：
第一種方法
package com.bjsxt.struts2.user.action;
import java.util.Map;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction1 extends ActionSupport {
private Map request;
private Map session;
private Map application;
public LoginAction1() {
request = (Map)ActionContext.getContext().get("request");
session = ActionContext.getContext().getSession();
application = ActionContext.getContext().getApplication();
}
public String execute() {
request.put("r1", "r1");
session.put("s1", "s1");
application.put("a1", "a1");
return SUCCESS;
}
}
通過取得Struts的Action的上下文來取得上述三種元素，map類型的。
方法二
package com.bjsxt.struts2.user.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.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction2 extends ActionSupport implements
RequestAware,SessionAware,
ApplicationAware {
private Map<String, Object> request;
private Map<String, Object> session;
private Map<String, Object> application;
// IOC
public String execute() {
request.put("r1", "r1");
session.put("s1", "s1");
application.put("a1", "a1");
return SUCCESS;
}
@Override
public void setRequest(Map<String, Object> request) {
this.request = request;
}
@Override
public void setSession(Map<String, Object> session) {
this.session = session;
}
@Override
public void setApplication(Map<String, Object> application) {
this.application = application;
}
}
通過Struts注入進來三個元素，map類型。
前台jsp頁麵獲取後台值的方式
<s:property value="#request.r1> | <%=request.getAttribute("r1")%>
<s:property value="#session.s1"/> | <%=session.getAttribute("s1")%>
<s:property value="#application.a1"/> | <%=application.getAttribute("a1")%>
方法三
package com.bjsxt.struts2.user.action;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction3 extends ActionSupport {
private HttpServletRequest request;
private HttpSession session;
private ServletContext application;
public LoginAction3() {
request = ServletActionContext.getRequest();
session = request.getSession();
application = session.getServletContext();
}
public String execute() {
request.setAttribute("r1", "r1");
session.setAttribute("s1", "s1");
application.setAttribute("a1", "a1");
return SUCCESS;
}
}
取得的是真實的類型
方法四
package com.bjsxt.struts2.user.action;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.interceptor.ServletRequestAware;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction4 extends ActionSupport implements
ServletRequestAware {
private HttpServletRequest request;
private HttpSession session;
private ServletContext application;
public String execute() {
request.setAttribute("r1", "r1");
session.setAttribute("s1", "s1");
application.setAttribute("a1", "a1");
return SUCCESS;
}
@Override
public void setServletRequest(HttpServletRequest request) {
this.request = request;
this.session = request.getSession();
this.application = session.getServletContext();
}
}
依賴注入，取得的是真實類型
最後更新：2017-04-02 22:16:02