(jvx)

REST Storage Client

If you need data from a REST service, it's super easy to call the REST service with JVx. The JVx REST services are based on RESTlet and the library should be available in your application as well. To try it out, simply create a unit test:

ContactClient.java

import java.util.List;
import java.util.Map;
 
import org.junit.Test;
import org.restlet.data.ChallengeScheme;
import org.restlet.resource.ClientResource;
 
import com.sibvisions.rad.server.http.rest.JSONUtil;
import com.sibvisions.util.type.StringUtil;
 
public class ContactClient
{
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Test methods
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
    @Test
    public void getContacts() throws Exception
    {
        ClientResource cres = new ClientResource("https://cloud.sibvisions.com/demoerp/services/rest/DemoERP/Customers/data/customer/");
        cres.setChallengeResponse(ChallengeScheme.HTTP_BASIC, "manager", "manager");
 
        List<Map<String, Object>> list = JSONUtil.getObject(cres.get(), List.class);
 
        for (Map<String, Object> m : list)
        {
            //System.out.println(StringUtil.toString(m.keySet()));
 
            System.out.println(m.get("ID") + ": " + m.get("FIRSTNAME") + " " + m.get("SURNAME"));
        }
    }
}

The response is e.g.

[
   {
      "ID":730,
      "COMPANY":"adsad",
      "FIRSTNAME":"alasafsd",
      "SURNAME":"asf test",
      "EMAIL":"sadadsaa",
      "ADDRESS":"1",
      "ZIP":"1",
      "CITY":"2",
      "CUSTOMERSINCE":"2016-04-30T22:00:00.000+0000",
      "TITL_ID":1,
      "TITL_TITLE":"Dr.",
      "SALU_ID":1,
      "SALU_SALUTATION":"Male",
      "CUSTOMER_NR":"CN - 730"
   },
   {
      "ID":634,
      "COMPANY":"helDFF",
      "FIRSTNAME":"Peter",
      "SURNAME":"Fall",
      "EMAIL":"oooo",
      "ADDRESS":"zjr",
      "ZIP":"1235",
      "CITY":"www",
      "CUSTOMERSINCE":"2016-03-09T23:00:00.000+0000",
      "TITL_ID":1,
      "TITL_TITLE":"Dr.",
      "SALU_ID":2,
      "SALU_SALUTATION":"Female",
      "CUSTOMER_NR":"CN - 634"
   },
   {
      "ID":2,
      "COMPANY":"Excompany",
      "FIRSTNAME":"ddddd",
      "SURNAME":"eeee",
      "EMAIL":"susi.summ@excompany.com",
      "ADDRESS":"Street 2",
      "ZIP":"1100",
      "CITY":"Vienna",
      "CUSTOMERSINCE":"2012-12-01T23:00:00.000+0000",
      "TITL_ID":1,
      "TITL_TITLE":"Dr.",
      "SALU_ID":1,
      "SALU_SALUTATION":"Male",
      "CUSTOMER_NR":"CN - 2"
   },
   {
      "ID":750,
      "COMPANY":"333",
      "FIRSTNAME":"abcefe",
      "SURNAME":"555",
      "EMAIL":"Schider.ngai@somehost.com",
      "ADDRESS":"Far Far Away",
      "ZIP":"55555",
      "CITY":"zxcvasd",
      "CUSTOMERSINCE":null,
      "TITL_ID":1,
      "TITL_TITLE":"Dr.",
      "SALU_ID":1,
      "SALU_SALUTATION":"Male",
      "CUSTOMER_NR":"CN - 750"
   }
]

You could integrate the REST call in your business logic, see Calling a server-side action. If you need the result in your GUI, it's also possible to create a custom storage. We use a simple statful storage for our example, but you could also implement a stateless storage. Here's the storage:

ContactStorage.java

public class ContactStorage extends AbstractMemStorage
{
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Initialization
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
    /**
     * Creates a new instance of <code>ContactStorage</code>.
     */
    public ContactStorage()
    {
    }
 
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // Abstract methods implementation
    //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
    @Override
    public RowDefinition getRowDefinition() throws ModelException
    {
        RowDefinition rdef = new RowDefinition();
        rdef.addColumnDefinition(new ColumnDefinition("ID", new BigDecimalDataType()));
        rdef.addColumnDefinition(new ColumnDefinition("FIRST"));
        rdef.addColumnDefinition(new ColumnDefinition("LAST"));
 
        rdef.setPrimaryKeyColumnNames(new String[] {"ID"});
 
        rdef.setColumnView(null, new ColumnView(rdef));
 
        return rdef;
    }
 
    @Override
    public void loadData(MemDataBook pBook, ICondition pCondition) throws ModelException
    {
        pBook.close();
        pBook.open();
 
        ClientResource cres = new ClientResource("https://cloud.sibvisions.com/demoerp/services/rest/DemoERP/Customers/data/customer/");
        cres.setChallengeResponse(ChallengeScheme.HTTP_BASIC, "manager", "manager");
 
        try
        {
            List<Map<String, Object>> list = JSONUtil.getObject(cres.get(), List.class);
 
            for (Map<String, Object> m : list)
            {
                pBook.insert(false);
                pBook.setValues(new String[] {"ID", "FIRST", "LAST"}, 
                                new Object[] {new BigDecimal((BigInteger)m.get("ID")), m.get("FIRSTNAME"), m.get("SURNAME")} ); 
            }
 
            pBook.saveAllRows();
        }
        catch (IOException ioe)
        {
            throw new ModelException(ioe);
        }
    }
 
    @Override
    public void insert(DataBookEvent pEvent) throws ModelException
    {
    }
 
    @Override
    public void update(DataBookEvent pEvent) throws ModelException
    {
    }
 
    @Override
    public void delete(DataBookEvent pEvent) throws ModelException
    {
    }
 
}

Our storage doesn't support insert/update/delete/filtering/sort. Only fetching data is implemented. But if you use client filtering/sort, it will work well.

The storage is ready to use with life-cycle objects:

Contacts.java

public IStorage getContacts() throws Exception
{
    ContactStorage storage = (ContactStorage)get("contacts");
 
    if (storage == null)
    {
        storage = new ContactStorage();
        storage.open();
 
        put("contacts", storage);
    }
 
    return storage;
}

And on the client side, use a RemoteDataBook as usual:

RemoteDataBook rdbContacts = new RemoteDataBook();
rdbContacts.setName("contacts");
rdbContacts.setDataSource(getDataSource());
//because our storage doesn't support remote filtering/sort
rdbContacts.setMemFilter(true);
rdbContacts.setMemSort(true);
rdbContacts.open();

And here's an example application:

Note

It's also possible to use other REST libraries, like:

Using RESTlet may be an option because it's used from JVx and thanks to JSONUtil it's easy to access the JSON object from the Response.

REST Storage Client picture_as_pdf

REST Storage Client