Action内でセッションを破棄してから新たなセッションを取得する方法。リダイレクトアクションを使う。

SampleAction.java

import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;
import org.apache.struts2.dispatcher.SessionMap;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.SessionAware;

import com.opensymphony.xwork2.ActionSupport;

@Results({
	@Result(name = "success", type = "dispatcher", location = "session.jsp"),
	@Result(name = "newSession" , type = "redirectAction" , params={"actionName","sessionId"})
})
public class SessionSampleAction extends ActionSupport implements SessionAware , ServletRequestAware {
	@Action("sessionId")
	public String sessionIdCheck() throws Exception {

		HttpSession httpSession = request.getSession();
		this.session.put("id", httpSession.getId());

		return "success";
	}

	@Action("sessionClear")
	public String sessionRemove() throws Exception {

		((SessionMap<String,Object>)session).invalidate();
		return "newSession";
	}
  
	@Override
	public void setSession(Map<String, Object> session) {
		this.session = session;
	}

	private Map<String,Object> session;

	@Override
	public void setServletRequest(HttpServletRequest request) {
		this.request = request;
	}

	private HttpServletRequest request;
}