问题描述
我在JSF 2属性绑定方面遇到问题,老实说,我在这里碰壁.
I have problem with JSF 2 property binding and honestly I hit a wall here..
我要完成的工作是:一个请求范围的bean(loginBean)处理登录操作,并将用户名存储在会话范围的bean(userBean)中.我想通过@ManagedProperty将userBean注入loginBean,但是当调用loginBean.doLoginAction时,userBean设置为null.
What I want to accomplish is this: a request-scoped bean (loginBean) process login action and stores username in the session-scoped bean (userBean). I want to inject userBean into loginBean via @ManagedProperty, but when loginBean.doLoginAction is called, userBean is set to null.
这是代码:
UserBean类
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
@ManagedBean
@SessionScoped
public class UserBean {
private String username;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public boolean isLogged() {
if (username != null)
return true;
return false;
}
}
loginBean类:
loginBean class:
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.RequestScoped;
@ManagedBean
@RequestScoped
public class LoginBean {
@ManagedProperty(value = "userBean")
private UserBean userBean;
private String name;
private String password;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public UserBean getUserBean() {
return userBean;
}
public void setUserBean(UserBean userBean) {
this.userBean = userBean;
}
public String doLoginAction() {
if (name.equals("kamil") && password.equals("kamil")) {
userBean.setUsername(name);
}
return null;
}
public String doLogoutAction() {
return null;
}
}
有什么想法我在这里做错了吗?
Any ideas what I'm doing wrong here?
推荐答案
您需要指定EL表达式#{}
,而不是纯字符串:
You need to specify an EL expression #{}
, not a plain string:
@ManagedProperty(value = "#{userBean}")
private UserBean userBean;
或更短,因为value
服装已经是默认服装:
or, shorter, since the value
attirbute is the default already:
@ManagedProperty("#{userBean}")
private UserBean userBean;
另请参见:
- JSF2中的通信-相互之间注入托管Bean
- Communication in JSF2 - Injecting managed beans in each other
See also:
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