package br.com.caelum.vraptor.deserialization;
import java.io.InputStream;
import java.lang.reflect.Method;
import br.com.caelum.vraptor.http.ParameterNameProvider;
import br.com.caelum.vraptor.interceptor.TypeNameExtractor;
import br.com.caelum.vraptor.resource.ResourceMethod;
import br.com.caelum.vraptor.serialization.xstream.VRaptorClassMapper;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.HierarchicalStreamDriver;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
import com.thoughtworks.xstream.mapper.MapperWrapper;
@Deserializes({"application/json","json"})
public class JsonDeserializer implements Deserializer{
private final ParameterNameProvider provider;
public JsonDeserializer(ParameterNameProvider provider,TypeNameExtractor extractor) {
this.provider = provider;
this.extractor = extractor;
}
private final TypeNameExtractor extractor;
private HierarchicalStreamDriver driver = new JettisonMappedXmlDriver();
public Object[] deserialize(InputStream inputStream, ResourceMethod method) {
Method javaMethod = method.getMethod();
Class<?>[] types = javaMethod.getParameterTypes();
if (types.length == 0) {
throw new IllegalArgumentException("Methods that consumes representations must receive just one argument: the root element");
}
XStream xStream = getConfiguredXStream(javaMethod, types);
Object[] params = new Object[types.length];
chooseParam(types, params, xStream.fromXML(inputStream));
return params;
}
/**
* Returns an xstream instance already configured.
*/
public XStream getConfiguredXStream(Method javaMethod, Class<?>[] types) {
XStream xStream = getXStream();
aliasParams(javaMethod, types, xStream);
return xStream;
}
private void chooseParam(Class<?>[] types, Object[] params, Object deserialized) {
for (int i = 0; i < types.length; i++) {
if (types[i].isInstance(deserialized)) {
params[i] = deserialized;
}
}
}
private void aliasParams(Method method, Class<?>[] types, XStream deserializer) {
String[] names = provider.parameterNamesFor(method);
for (int i = 0; i < names.length; i++) {
deserializer.alias(names[i], types[i]);
}
}
/**
* Extension point to configure your xstream instance.
* @return the configured xstream instance
*/
protected XStream getXStream() {
return new XStream(getHierarchicalStreamDriver()) {
{setMode(NO_REFERENCES);}
@Override
protected MapperWrapper wrapMapper(MapperWrapper next) {
return new VRaptorClassMapper(next, extractor);
}
};
}
/**
* You can override this method for configuring Driver before serialization
*/
protected HierarchicalStreamDriver getHierarchicalStreamDriver() {
return this.driver;
}
}