Struts2 Action class gets ServletAPI

In Struts2, HttpServletRequest, HttpSession, and ServletContext are encapsulated and decoupled, and three Map objects are constructed to replace the listed objects.


method of obtaining:

① acquisition (the acquisition only way to get the domain space ServletAPI, and through ActionContext non-real specific ServletAPI )

    Put data into the Request domain space: ActionContext.getContext().put("req", "req_value");

    Put data into the Session domain space: ActionContext.getContext().getSession().put("ses", "ses_value");

    Put data into the Application domain space: ActionContext.getContext().getApplication().put("app", "app_value");


② Get through ServletActionContext ( get the real specific ServletAPI )

    Put data into the Request domain space: ServletActionContext.getRequest().setAttribute("req", "req_value");

    Put data into the Session domain space: ServletActionContext.getRequest().getSession().setAttribute("ses", "ses_value");

    Put data into the Application domain space: ServletActionContext.getServletContext().setAttribute("app", "app_value");


③ Obtain by implementing specific interfaces (action class implements RequestAware, SessionAware, ApplicationAware interfaces)

// 三大成员变量
private Map<String, Object> req;
private Map<String, Object> ses;
private Map<String, Object> app;

// 三大成员属性
public void setRequest(Map<String, Object> request) {
	this.req = request;
}

public void setSession(Map<String, Object> session) {
	this.ses = session;
}

public void setApplication(Map<String, Object> application) {
	this.app = application;
}

public String execute() {
	req.put("req", "req_value");
	ses.put("ses", "ses_value");
	app.put("app", "app_value");
	return "success";
}