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Vaadin - REST example
Tobias Demuth: Next problem might be the fact that you are requesting a Customer but actually receiving a List of Customers. As far as I remember, it is probably better to use array here and to pass the correct class-type into get().
(new Customer[0]).getClass();
Finally I could solve the problem. There were few steps I had to do. So let's start with my model class Customer.java
public class Customer {
private String firstname;
private String lastName;
private Long id;
public Customer() {
}
public Customer(Long id,String firstname,String lastname) {
this.firstname = firstname;
this.lastName = lastname;
this.id = id;
}
@Override
public String toString() {
return "Customer [firstname=" + firstname + ", lastName=" + lastName + ", id=" + id + "]";
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}When using rest services with a content-type like json or xml you have to be sure, that your model class can be converted to the specific format. In my case I decided to use xml. Therefore I had to use the annotation @XmlRootElement. You only need to put this annotation at the top of your class.. nothing more needed.
The next step was to edit my Rest-Client.java:
public List<Customer>findByName(String firstname,String lastname) {
List<Customer>customerList = new ArrayList<Customer>();
customerList = webtarget.path("server").
path("restserver").
path("findByName").
queryParam("firstname", firstname).
queryParam("lastname", lastname).
request().
accept(MediaType.APPLICATION_XML).
get(new GenericType<List<Customer>>(){});
return customerList;
}I expect an xml content-type from the server. This is the reason why I use accept(MediaType.APPLICATION_XML). In case you receive a list of items, you could use GenericType<List<Customer>>(){};
The fnal part - My Server.java:
@Path("/restserver")
public class Server {
@Path("/findByName")
@GET
@Produces(MediaType.APPLICATION_XML)
public GenericEntity<List<Customer>>findByName(@QueryParam("firstname")String firstname,@QueryParam("lastname") String lastname) throws ClassNotFoundException, SQLException
{
List<Customer>customerList = DBConnection.findByName(firstname, lastname);
GenericEntity<List<Customer>>
list = new GenericEntity<List<Customer>>(customerList) {
};
return list;
}Nothing special here. Just looking for some data in the database and returning them as a type of List<Customer>.
I hope this information could be helpful for someone.
Best regards,
Nazar Medeiros