JSF:会话作用域托管bean的属性变为null

我正在玩JavaEE7，并试图用一个简单的登录机制编写一个webapp

有一个名为

User

的EJB实体类与JPA一起持久化，它保存着关于用户的数据。在WAR中，一个名为

UserManagedBean

的会话范围的托管bean负责跟踪当前用户，因此它有一个

user

类型的属性，当有人成功登录时设置该属性。筛选器正在监视此属性的值，并在必要时重定向到登录页。当然，

User

和

UserManagedBean

都是可序列化的（实现接口并且不包含任何不可序列化的内容）

我的问题是，在成功登录后，刷新页面会使我返回登录页面，而我以前设置的

user

属性现在为空（实际上这就是过滤器触发重定向的原因）

以下是我尝试过的：

• 逻辑和数据分离：UserManagedBean现在只有这一个属性和几个助手方法，没有EJB，与JavaMagic没有任何关系
• 尝试将web.xml中的

  javax.faces.STATE\u SAVING\u方法

  context参数同时设置为服务器和客户端，未发生任何更改
• 已验证会话范围的托管bean是否保持不变：只创建了其中一个，但不知何故，在从登录页面导航后，user的值为null
• 根据NetBeans调试器，除了将

  用户

  字段设置为登录用户外，不会访问该字段
• 指定自定义序列化方法表明UserManagedBean在实验期间未序列化或反序列化
• Chrome中的调试表明会话ID保存在cookie中，并且在

  user

  的值丢失时不会更改
• 未检测到任何异常

我一定错过了一些琐碎的事情，任何帮助都将不胜感激

（更新：它确实微不足道，与JSF或托管bean无关，请参见下面我的答案。）

我的代码如下：

用户

类别：

@Entity(name = "USERS")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    private String username;
    private boolean administrator;
    private byte[] salt;
    private byte[] passwordHash;

    public String getUsername() {
        return username;
    }

    public void setUsername(String userName) {
        this.username = userName;
    }

    public boolean isAdministrator() {
        return administrator;
    }

    public void setAdministrator(boolean administrator) {
        this.administrator = administrator;
    }

    public byte[] getSalt() {
        return salt;
    }

    public void setSalt(byte[] salt) {
        this.salt = salt;
    }

    public byte[] getPasswordHash() {
        return passwordHash;
    }

    public void setPasswordHash(byte[] passwordHash) {
        this.passwordHash = passwordHash;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (username != null ? username.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "hu.bme.aut.mv.testbay.ejb.entities.User[ id=" + username + " ]";
    }

}

@ManagedBean(name = "userManagedBean")
@SessionScoped
public class UserManagedBean implements Serializable {
    private static final long serialVersionUID = 1L;

    private User currentUser;

    public User getCurrentUser() {
        return currentUser;
    }

    public void setCurrentUser(User user) {
        this.currentUser = user;
    }

    public boolean isLoggedIn() {
        return currentUser != null;
    }

    public boolean isAdmin() {
        return currentUser != null && currentUser.isAdministrator();
    }

    public String logout() {
        currentUser = null;
        return "/faces/index.xhtml";
    }

    /**
     * Creates a new instance of UserManagedBean
     */
    public UserManagedBean() {
        System.out.println("UserManagedBean constructed!");
    }
}

@ManagedBean
@RequestScoped
public class LoginManagedBean implements Serializable {

    @EJB
    private AuthenticationSessionBeanLocal authBean;

    @ManagedProperty("#{userManagedBean}")
    private UserManagedBean userManagedBean;

    @PostConstruct
    public void Dummy() {
        User user = userManagedBean.getCurrentUser();
    }

    public UserManagedBean getUserManagedBean() {
        return userManagedBean;
    }

    public void setUserManagedBean(UserManagedBean userManagedBean) {
        this.userManagedBean = userManagedBean;
    }

    private String username;
    private String password;

    //Some getters and setters...
    //...

    public String login() throws NoSuchAlgorithmException {
        if (authenticate(username, password)) {
            if (userManagedBean.getCurrentUser().isAdministrator())
                return "/faces/admin/welcome.xhtml?faces-redirect=true";
            else
                return "/faces/testing/welcome.xhtml?faces-redirect=true";
        }
        return null;   
    }

    private boolean authenticate(String username, String password) throws NoSuchAlgorithmException {
        userManagedBean.setCurrentUser(authBean.authenticate(username, password));
        if (userManagedBean.getCurrentUser() == null)
            return false;
        return true;
    }

    //Constructor and methods...
    //...
}

UserManagedBean

class:

@Entity(name = "USERS")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    private String username;
    private boolean administrator;
    private byte[] salt;
    private byte[] passwordHash;

    public String getUsername() {
        return username;
    }

    public void setUsername(String userName) {
        this.username = userName;
    }

    public boolean isAdministrator() {
        return administrator;
    }

    public void setAdministrator(boolean administrator) {
        this.administrator = administrator;
    }

    public byte[] getSalt() {
        return salt;
    }

    public void setSalt(byte[] salt) {
        this.salt = salt;
    }

    public byte[] getPasswordHash() {
        return passwordHash;
    }

    public void setPasswordHash(byte[] passwordHash) {
        this.passwordHash = passwordHash;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (username != null ? username.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "hu.bme.aut.mv.testbay.ejb.entities.User[ id=" + username + " ]";
    }

}

@ManagedBean(name = "userManagedBean")
@SessionScoped
public class UserManagedBean implements Serializable {
    private static final long serialVersionUID = 1L;

    private User currentUser;

    public User getCurrentUser() {
        return currentUser;
    }

    public void setCurrentUser(User user) {
        this.currentUser = user;
    }

    public boolean isLoggedIn() {
        return currentUser != null;
    }

    public boolean isAdmin() {
        return currentUser != null && currentUser.isAdministrator();
    }

    public String logout() {
        currentUser = null;
        return "/faces/index.xhtml";
    }

    /**
     * Creates a new instance of UserManagedBean
     */
    public UserManagedBean() {
        System.out.println("UserManagedBean constructed!");
    }
}

@ManagedBean
@RequestScoped
public class LoginManagedBean implements Serializable {

    @EJB
    private AuthenticationSessionBeanLocal authBean;

    @ManagedProperty("#{userManagedBean}")
    private UserManagedBean userManagedBean;

    @PostConstruct
    public void Dummy() {
        User user = userManagedBean.getCurrentUser();
    }

    public UserManagedBean getUserManagedBean() {
        return userManagedBean;
    }

    public void setUserManagedBean(UserManagedBean userManagedBean) {
        this.userManagedBean = userManagedBean;
    }

    private String username;
    private String password;

    //Some getters and setters...
    //...

    public String login() throws NoSuchAlgorithmException {
        if (authenticate(username, password)) {
            if (userManagedBean.getCurrentUser().isAdministrator())
                return "/faces/admin/welcome.xhtml?faces-redirect=true";
            else
                return "/faces/testing/welcome.xhtml?faces-redirect=true";
        }
        return null;   
    }

    private boolean authenticate(String username, String password) throws NoSuchAlgorithmException {
        userManagedBean.setCurrentUser(authBean.authenticate(username, password));
        if (userManagedBean.getCurrentUser() == null)
            return false;
        return true;
    }

    //Constructor and methods...
    //...
}

过滤器（

doBeforeProcessing

）：

更新：

重要的是要注意，用户只需正确设置一次，就可以正常地过渡到欢迎屏幕。但是，nex请求发现用户属性为空

触发身份验证的代码位于请求范围

LoginManagedBean

类中：

@Entity(name = "USERS")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    private String username;
    private boolean administrator;
    private byte[] salt;
    private byte[] passwordHash;

    public String getUsername() {
        return username;
    }

    public void setUsername(String userName) {
        this.username = userName;
    }

    public boolean isAdministrator() {
        return administrator;
    }

    public void setAdministrator(boolean administrator) {
        this.administrator = administrator;
    }

    public byte[] getSalt() {
        return salt;
    }

    public void setSalt(byte[] salt) {
        this.salt = salt;
    }

    public byte[] getPasswordHash() {
        return passwordHash;
    }

    public void setPasswordHash(byte[] passwordHash) {
        this.passwordHash = passwordHash;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (username != null ? username.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "hu.bme.aut.mv.testbay.ejb.entities.User[ id=" + username + " ]";
    }

}

@ManagedBean(name = "userManagedBean")
@SessionScoped
public class UserManagedBean implements Serializable {
    private static final long serialVersionUID = 1L;

    private User currentUser;

    public User getCurrentUser() {
        return currentUser;
    }

    public void setCurrentUser(User user) {
        this.currentUser = user;
    }

    public boolean isLoggedIn() {
        return currentUser != null;
    }

    public boolean isAdmin() {
        return currentUser != null && currentUser.isAdministrator();
    }

    public String logout() {
        currentUser = null;
        return "/faces/index.xhtml";
    }

    /**
     * Creates a new instance of UserManagedBean
     */
    public UserManagedBean() {
        System.out.println("UserManagedBean constructed!");
    }
}

@ManagedBean
@RequestScoped
public class LoginManagedBean implements Serializable {

    @EJB
    private AuthenticationSessionBeanLocal authBean;

    @ManagedProperty("#{userManagedBean}")
    private UserManagedBean userManagedBean;

    @PostConstruct
    public void Dummy() {
        User user = userManagedBean.getCurrentUser();
    }

    public UserManagedBean getUserManagedBean() {
        return userManagedBean;
    }

    public void setUserManagedBean(UserManagedBean userManagedBean) {
        this.userManagedBean = userManagedBean;
    }

    private String username;
    private String password;

    //Some getters and setters...
    //...

    public String login() throws NoSuchAlgorithmException {
        if (authenticate(username, password)) {
            if (userManagedBean.getCurrentUser().isAdministrator())
                return "/faces/admin/welcome.xhtml?faces-redirect=true";
            else
                return "/faces/testing/welcome.xhtml?faces-redirect=true";
        }
        return null;   
    }

    private boolean authenticate(String username, String password) throws NoSuchAlgorithmException {
        userManagedBean.setCurrentUser(authBean.authenticate(username, password));
        if (userManagedBean.getCurrentUser() == null)
            return false;
        return true;
    }

    //Constructor and methods...
    //...
}

---

这确实是一个愚蠢的错误

NetBeans断点没有发出信号，但该字段确实是由注销函数访问的，该函数在每次导航后调用。结果是我误用了PrimeFaces组件。我想将注销命令按钮的

output

属性设置为

UserManagedBean

上的注销方法，但NetBeans autocomplete在方法名称后放了一对括号，我没有注意到。因此，EL评估了

logout（）

方法以将结果设置为登录页面的返回url，而不是得到一个错误，即

output

属性的工作方式与

action

不同，应该以字符串形式接收路径，但该方法也会以静默方式注销用户

---

我唯一想知道的是，NetBeans是如何在set方法和字段断点中都失败的，在访问字段时应该触发该断点。

您可以将变量放入视图（即视图范围），然后使用getter和setter检索/修改它。

---

这还允许您通过模拟视图响应以更好的方式测试控制器。

我不清楚您是如何使用过滤器的。通常，登录页面是一个请求范围的无用户页面，登录操作调用筛选代码来创建/检索用户实体并将其分配给会话范围的UserManagerBean。另一个请求范围的托管bean在EJB的帮助下进行身份验证并检索用户实体，在始终存在的UserManagedBean中设置它。当请求登录或注册表单以外的页面时，将激活筛选器，并检查UserManagedBean实例是否包含用户实体。注销会将此属性设置为null（显然，其他内容会无意中设置为null）。您如何从登录屏幕转换到您的主身份验证页面？@Leo，请查看我的更新。

session.getAttribute（“userManagedBean”）

。在获取属性之前，您在哪里设置了该属性？