Chapter 22. String marshalling for String based @*Param
@PathParam, @QueryParam, @MatrixParam, @FormParam, and @HeaderParam are represented as Strings in a raw HTTP request. These injected parameter types can be converted into objects if they have a valueOf(String) static method, or a constructor that takes one String parameter. If you have a class with valueOf(), or the String constructor is inappropriate for your HTTP request, you can plug in RESTEasy's proprietary @Provider:
package org.jboss.resteasy.spi;
public interface StringConverter<T>
{
T fromString(String str);
String toString(T value);
}
This interface lets you use your own customized String marshalling. It is registered in
web.xml under the resteasy.providers context-param. (See the Installation and Configuration chapter for details.) You can register it manually by calling the ResteasyProviderFactory.addStringConverter() method. A simple example of using the StringConverter follows:
import org.jboss.resteasy.client.ProxyFactory;
import org.jboss.resteasy.spi.StringConverter;
import org.jboss.resteasy.test.BaseResourceTest;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.MatrixParam;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;
import javax.ws.rs.ext.Provider;
public class StringConverterTest extends BaseResourceTest
{
public static class POJO
{
private String name;
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
@Provider
public static class POJOConverter implements StringConverter<POJO>
{
public POJO fromString(String str)
{
System.out.println("FROM STRNG: " + str);
POJO pojo = new POJO();
pojo.setName(str);
return pojo;
}
public String toString(POJO value)
{
return value.getName();
}
}
@Path("/")
public static class MyResource
{
@Path("{pojo}")
@PUT
public void put(@QueryParam("pojo")POJO q, @PathParam("pojo")POJO pp,
@MatrixParam("pojo")POJO mp, @HeaderParam("pojo")POJO hp)
{
Assert.assertEquals(q.getName(), "pojo");
Assert.assertEquals(pp.getName(), "pojo");
Assert.assertEquals(mp.getName(), "pojo");
Assert.assertEquals(hp.getName(), "pojo");
}
}
@Before
public void setUp() throws Exception
{
dispatcher.getProviderFactory().addStringConverter(POJOConverter.class);
dispatcher.getRegistry().addPerRequestResource(MyResource.class);
}
@Path("/")
public static interface MyClient
{
@Path("{pojo}")
@PUT
void put(@QueryParam("pojo")POJO q, @PathParam("pojo")POJO pp,
@MatrixParam("pojo")POJO mp, @HeaderParam("pojo")POJO hp);
}
@Test
public void testIt() throws Exception
{
MyClient client = ProxyFactory.create(MyClient.class, "http://localhost:8081");
POJO pojo = new POJO();
pojo.setName("pojo");
client.put(pojo, pojo, pojo, pojo);
}
}
