Output data from database in JSF page - database

Question

I am making a project using JSF, and I know how to get data from my view. I also know how to get data with the JDBC connector. And also how to put data in the view, from some objects, but my question is:
How to put data directly from my database, for example a list of person, in JSF, for example with the tag <h:outputText value="#{}"/> ?
I have found some examples with instantiate objects, but I did not found a real example with data from a DB.

Answer 1

JSF is just an MVC framework to develop web applications in Java. JSF doesn't associate with any data source at all. The only data JSF will use is retrieved from:
The data already stored in the proper object as attribute: HttpServletRequest, HttpSession or ServletContext.
The request/view/session/application context in form of fields in the managed beans, recognized by classes decorated as #ManagedBeans or #Named if using CDI. The data of these fields will be stored as attributes in the objects mentioned in the section above, depending on the scope of the managed bean.
By knowing this, then the only thing you should worry about is to fill the fields in your managed beans. You can fill them with incoming data from database, from a web service or whatever data source you have in mind.
For example, if you want/need to populate your data to pre process a request, you can do the following:
#ManagedBean
#ViewScoped
public class SomeBean {
List<Entity> entityList;
#PostConstruct
public void init() {
SomeService someService = new SomeService();
entityList = someService.findEntityList();
}
//getters and setters for the list...
}
//as you can see, this class is just pure Java
//you may use other frameworks if you want/need
public class SomeService {
public List<Entity> findEntityList() {
String sql = "SELECT field1, field2... FROM table";
List<Entity> entityList = new ArrayList<>();
try (Connection con = ...; //retrieve your connection somehow
PreparedStatement pstmt = con.prepareStatement(sql)) {
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
Entity entity = new Entity();
entity.setField1(rs.getString("field1"));
entity.setField2(rs.getString("field2"));
//...
entityList.add(entity);
}
} catch (Exception e) {
//handle exception ...
e.printStackTrace();
}
return entityList;
}
}