how to transfer parameter from managedbean to a jsf page

问题

I want to transfer a parameter from a jsf page to another jsf page. Like this:

a.xhtml

<h:form>
    <h:commandLink class="navi" value="press"
               action="#{Bean.action}">
        <f:param name="id" value="5555" />
    </h:commandLink>
</h:form>

Bean.java

public String action() {
    HttpServletRequest request = (HttpServletRequest) FacesContext
            .getCurrentInstance().getExternalContext().getRequest();
    String param = request.getParameter("id");
    return "b?id=" + param;
}

b.xhtml

<h:inputText value=#{param.id} />

By previous way, I transfer id from a.xhtml to b.xhtml, but I don't want to expose the parameter like "...b.xhtml?id=5555" outside because of this line:

return "b?id=" + param;

And the scope of ManagedBean is request. How can I do to solve this problem? Thanks.

回答1:

You could also try viewParam

<f:metadata>
    <f:viewParam name="id" value="#{bean.id}" />
</f:metadata>

It does basically the following:

Get the request parameter value by name id.
Convert and validate it if necessary (you can use required, validator and converter attributes and nest a and in it like as with )
If conversion and validation succeeds, then set it as a bean property represented by #{bean.id}

You could pass the id on outcome link (b.xhtml?id=1, for example) and retrieve it on any Managed Bean.

回答2:

If you are using JSF 2 or EL 2.2 you can pass it as a parameter to the method

<h:commandLink class="navi" value="press" action="#{Bean.action(5555)}" />

回答3:

If your bean is session scoped, this is easy.

Bean.java

private String param;

public String action() {
    HttpServletRequest request = (HttpServletRequest) FacesContext
            .getCurrentInstance().getExternalContext().getRequest();
    param = request.getParameter("id");
    return "b?id=" + param;
}

public String getParam() {
    return param;
}

xhtml

<h:inputText value=#{bean.param} />

来源：https://stackoverflow.com/questions/16622281/how-to-transfer-parameter-from-managedbean-to-a-jsf-page

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jsf

facelets