從JSF頁面傳遞參數至後端backing bean

1. 方法傳遞

在JSF 2.0，可以透過這樣的方法表達參數值 #{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

透過f：param標籤傳遞參數值，並通過後台bean的接收參數。

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

透過 f:atribute 標籤傳遞參數值，並通過後台bean的接收參數。

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

透過 f:setPropertyActionListener 標籤, 直接將設定值set到您的backing bean的屬性.

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"
 } 
 
}