JSF Managed Bean
JSF Managed Bean
1. Bean class have Data Member
and getter and setter
2. A managed bean is a
java bean class which contains data member and method (business logic).
3. A managed bean
managed by JSF frameworks
4. A managed bean act as
a model for JSP application
5. A managed bean
configured in faces-config.xml file or by Annotation
Managed Bean function performed
1. Component
Data Validation
2. Component’s
Event Handling
3. Determine
the next page which must to Navigated by JSF application
Example: Bean Class
public class Employee {
private String empID;
public String getEmpId() {
return name;
}
public void setEmpId(String empId) {
this.empId = empId;
}
}
Managed Bean Ways to Configure
1. XML configuration :
<managed-bean>
<managed-bean-name>employee</managed-bean-name>
<managed-bean-class>Employee</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
2. Annotation Based configure:
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
@ManagedBean /* ManagedBean annotation */
@RequestScoped /* Scope annotation */
public class Employee {
private String empID;
public String getEmpId() {
return name;
}
public void setEmpId(String empId) {
this.empId = empId;
}
}
@ManagedBean:
1.
It will
register a class as a resource in JSF framework
2.
This calls not need to configured in config
resource file
@RequestScoped:
1.
It provide Score for managed bean
2.
It will allow you to store your bean in list of
scopes
a.
Request (@RequestScoped): Bean Created when a request for this bean comes and destroyed once the
completed the Response
b.
View (@ViewScoped): Bean Created when a request involving this bean
comes and destroyed whenever view will be changed.
c.
Session (@SessionScoped): Bean
Created when a request for this bean comes and destroyed when session
terminates.
d. Application
(@ApplicationScoped): Bean Created when a request involving this bean
comes and remains for whole duration till the application runs on web
e. None (@NoneScoped): Bean scopes
not defined in this application
f. Custom (@CustomScoped): Bean scopes is non standard, its value must be
configured as java.util.map, custom score are use very rarely
Eagar & Lazy Managed Bean
Lazy
1. By Default managed bean are Lazy
2. Lazy managed Bean instantiate only
when requested from the application
Eagar
1. To enable Eagar managed bean @ManagedBean(eager=true)
2. @ManagedBean(eager=true) Annotation need to apply on the Class level
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