As i know,there are 4 ways to pass a parameter value from JSF page to backing bean :
- Method expression (JSF 2.0)
- f:param
- f:attribute
- f:setPropertyActionListener
Let see example one by one :
1. Method expression
Since JSF 2.0, you are allow to pass parameter value in the method expression like this #{bean.method(param)}.
JSF page…
<h:commandButton action="#{user.editAction(delete)}" />
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{ public String editAction(String id) {
//id = "delete"
} }
2. f:param
Pass parameter value via f:param
tag and get it back via request parameter in backing bean.
JSF page…
<h:commandButton action="#{user.editAction}">
<f:param name="action" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{ public String editAction() { Map<String,String> params =
FacesContext.getExternalContext().getRequestParameterMap();
String action = params.get("action");
//... } }
3. f:atribute
Pass parameter value via f:atribute
tag and get it back via action listener in backing bean.
JSF page…
<h:commandButton action="#{user.editAction}" actionListener="#{user.attrListener}">
<f:attribute name="action" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{ String action; //action listener event
public void attrListener(ActionEvent event){ action = (String)event.getComponent().getAttributes().get("action"); } public String editAction() {
//...
} }
4. f:setPropertyActionListener
Pass parameter value via f:setPropertyActionListener
tag, it will set the value directly into your backing bean property.
JSF page…
<h:commandButton action="#{user.editAction}" >
<f:setPropertyActionListener target="#{user.action}" value="delete" />
</h:commandButton>
Backing bean…
@ManagedBean(name="user")
@SessionScoped
public class UserBean{ public String action; public void setAction(String action) {
this.action = action;
} public String editAction() {
//now action property contains "delete"
} }