我想知道如果用户处于会话中，是否可以使用Struts 2的<s:if>标记进行检查。
如果用户在会话中，我需要它显示Logout，否则Login。
我使用接口SessionAware进行登录操作，并使用这个类User。

package it.pwm.wynd.pojo.user;
public class User implements java.io.Serializable {
    private static final long serialVersionUID = 1L;
    private Integer idUser;
    private String name;
    private String username;
    private String password;
    private String email;
    public User() {
    }
    public User(String name, String username, String password, String email) {
        this.name = name;
        this.username = username;
        this.password = password;
        this.email = email;
    }
    public Integer getIdUser() {
        return this.idUser;
    }
    public void setIdUser(Integer idUser) {
        this.idUser = idUser;
    }
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getUsername() {
        return this.username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return this.password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return this.email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
}

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