Question

我正在尝试将一个托管bean注入另一个托管bean（我只需要在一个托管bean中执行操作，如果用户是loggen，并且该用户保存在另一个托管bean上）。但是返回NULL！每个托管bean链接到不同的XHTML页面，因此可能会创建一个新的HTTP会话？

第一个托管bean：

@Named(value = "travellerLoginManagedBean" )
@SessionScoped
public class travellerLoginManagedBean implements Serializable {

@EJB
private travellerUserEntityFacadeLocal travellerUserEntityFacade;

private String userName;
private String password;
private Boolean loggedIn;
/**
 * Creates a new instance of travellerLoginManagedBean
 */
public travellerLoginManagedBean() {
}

public Boolean getLoggedIn() {
    return loggedIn;
}

public void setLoggedIn(Boolean loggedIn) {
    this.loggedIn = loggedIn;
}

public String getUserName() {
    return userName;
}

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

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public Boolean validUser(){
    loggedIn=true;
    return travellerUserEntityFacade.checkLogin(this.userName, this.password)==true;
}

public String login() {
    if (validUser()==true){
        return "/travellerHome.xhtml";
    }else{
        FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Usuario y/o password incorrecto!"));
        return "/travellerLogin.xhtml";
    }

}

}

第二个托管bean：

@Named(value = "travellerSearchFlightsManagedBean")
@RequestScoped
public class travellerSearchFlightsManagedBean{


@EJB
private itineraryTravellerFacadeLocal itineraryTravellerFacade;

@EJB
private itineraryFacadeLocal itineraryFacade;

@ManagedProperty(value="#{travellerLoginManagedBean}")
private travellerLoginManagedBean loginBean;
private String departureLocation;
private String arrivalLocation;
private Date departureDate;
private int departureHour;
private int departureMinute;
private int numPassengers;
private int maxStops;
private String economyOrBusiness;
private ArrayList<itineraryDTO> itinerariesList;
private ArrayList<itineraryTraveller> searchList;
private itineraryTraveller selectedItinerary;
private String stopPrint;
private static final Logger LOG = Logger.getLogger(travellerSearchFlightsManagedBean.class.getName());

 ( ......)

public void reserveFlight(){
    if (loginBean.getLoggedIn()==true){
        System.out.println("iiiiiiiiiiiiiiiiin");
        //status reserved when traveller reserves an itinerary
        selectedItinerary.setStatus('r');
        //set the userName from the user who reserved this itinerary before persist it in a shared among all users db
        selectedItinerary.setUserName(loginBean.getUserName());
        //persist the reserved itinerary in the db
        itineraryTravellerFacade.create(selectedItinerary);
    }else{
        System.out.println("not     iiiiiiiiiiiiiiiiin");
        FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Must be logged in before reserving an itinerary"));
    }
}

}

Answer 1

为了工作，Bean注入需要：

添加@ManagedProperty注释（您已做过）
在faces-config.xml文件中添加其他Bean的引用。

来自Apache Documentation的faces-config.xml示例应该澄清：

<managed-bean>
    <managed-bean-name>neededBean</managed-bean-name>
    <managed-bean-class>fqn.to.NeededBean</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
</managed-bean>

<managed-bean>
    <managed-beaenter code heren-name>usingBean</managed-bean-name>
    <managed-bean-class>fqn.to.UsingBean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    <managed-property>
     <property-name>neededBean</property-name>
     <value>#{neededBean}</value>
    </managed-property>
</managed-bean>

在您的具体案例中：

NeededBean = travellerLoginManagedBean
UsingBean = travellerSearchFlightsManagedBean

Apache文档还指出使用Bean注入的唯一约束是：

using bean必须具有与所需bean相同或更短的范围
using bean必须有一个property-setter方法，它将所需的bean作为参数
bean之间不能存在托管依赖关系。

如果您需要更多信息，请查看Apache Documentation。

PS：我注意到你用小写字母写了类名，但是使用Java代码约定（CamelCase），每个类名都应该以大写字母开头。

托管属性返回null

1 个答案: