Generate h:panelGrid from Java list [duplicate] - jsf

Question

I am wondering how to display a List<T> as obtained below in a Facelet:
public List<T> searchByString(String string) {
return getEntityManager().createNamedQuery("Userdetails.findByUsername").setParameter("username", "%" + string + "%").getResultList();
}
Would a <h:dataTable> be a suitable way?

Answer 1

You're going need to iterate over it. JSF 2 offers three iteration components out the box. Provided that the User entity look like below,
#Entity
public class User {
private #Id Long id;
private String username;
private String email;
private LocalDate birthdate;
// Add/generate getters+setters.
}
and that the search results are assigned as a List<User> users property of a bean which is available as #{bean},
#Named #RequestScoped
public class Bean {
private List<User> users;
// Add/generate postconstruct+getter.
}
here are some examples based on it:
<h:dataTable>, an UI component which generates a HTML <table>.
<h:dataTable value="#{bean.users}" var="user">
<h:column>#{user.id}</h:column>
<h:column>#{user.username}</h:column>
<h:column>#{user.email}</h:column>
<h:column>#{user.birthdate}</h:column>
</h:dataTable>
<ui:repeat>, an UI component which generates no HTML markup (so, you'd have to write all that HTML in the desired fashion yourself, which could easily be changed to e.g. <ul><li>, or <dl><dt><dd>, or <div><span>, etc):
<table>
<ui:repeat value="#{bean.users}" var="user">
<tr>
<td>#{user.id}</td>
<td>#{user.username}</td>
<td>#{user.email}</td>
<td>#{user.birthdate}</td>
</td>
</ui:repeat>
</table>
<c:forEach>, a tag handler which runs during view build time instead of view render time (background explanation here: JSTL in JSF2 Facelets... makes sense?), it also doesn't produce any HTML markup:
<table>
<c:forEach items="#{bean.users}" var="user">
<tr>
<td>#{user.id}</td>
<td>#{user.username}</td>
<td>#{user.email}</td>
<td>#{user.birthdate}</td>
</td>
</c:forEach>
</table>
See also:
Java EE 6 tutorial - Adding components to a page - using <h:dataTable>
How and when should I load the model from database for h:dataTable

Answer 2

You can save your List in a class variable, give it a getter and (maybe) a setter. Declare searchByString method as void and call it with let's say a (provided you are using PrimeFaces):
<p:commandLink update="#form" process="#this" action="#{myBean.searchByString}">
myBean:
public void searchByString(String string) {
userList = getEntityManager().createNamedQuery("Userdetails.findByUsername").setParameter("username", "%" + string + "%").getResultList();
}
provided your table sits in a form that you just updated you could display the List in it.
<p:dataTable var="user" value="#{myBean.userList}">
<p:column headerText="Name">
<h:outputText value="#{user.name}" />
</p:column>
</p:dataTable>