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Difference between revisions of "EclipseLink/Examples/MOXy/MOXy JSON Provider"

Line 106: Line 106:
 
     </persistence-context-ref>
 
     </persistence-context-ref>
 
</web-app>
 
</web-app>
 +
</source>
 +
</div>
 +
 +
==Extending MOXyJsonProvider==
 +
 
 +
You can also extend MOXyJsonProvider to create your own '''MessageBodyReader/MessageBodyWriter'''.  The <tt>preReadFrom</tt> and preWriteTo methods can be overridden to customize the Unmarshaller/Marshaller that will be used by MOXy.
 +
 +
<div style="width:850px">
 +
<source lang="xml">
 +
package org.example;
 +
 +
import java.lang.annotation.Annotation;
 +
import java.lang.reflect.Type;
 +
 +
import javax.ws.rs.*;
 +
import javax.ws.rs.core.*;
 +
import javax.ws.rs.ext.Provider;
 +
import javax.xml.bind.*;
 +
 +
import org.eclipse.persistence.jaxb.MarshallerProperties;
 +
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;
 +
 +
@Provider
 +
@Produces(MediaType.APPLICATION_JSON)
 +
@Consumes(MediaType.APPLICATION_JSON)
 +
public class CustomerJSONProvider extends MOXyJsonProvider {
 +
 +
    @Override
 +
    public boolean isReadable(Class<?> type, Type genericType,
 +
            Annotation[] annotations, MediaType mediaType) {
 +
        return getDomainClass(genericType) == Customer.class;
 +
    }
 +
 +
    @Override
 +
    public boolean isWriteable(Class<?> type, Type genericType,
 +
            Annotation[] annotations, MediaType mediaType) {
 +
        return isReadable(type, genericType, annotations, mediaType);
 +
    }
 +
 +
    @Override
 +
    protected void preReadFrom(Class<Object> type, Type genericType,
 +
            Annotation[] annotations, MediaType mediaType,
 +
            MultivaluedMap<String, String> httpHeaders,
 +
            Unmarshaller unmarshaller) throws JAXBException {
 +
        unmarshaller.setProperty(MarshallerProperties.JSON_VALUE_WRAPPER, "$");
 +
    }
 +
 +
    @Override
 +
    protected void preWriteTo(Object object, Class<?> type, Type genericType,
 +
            Annotation[] annotations, MediaType mediaType,
 +
            MultivaluedMap<String, Object> httpHeaders, Marshaller marshaller)
 +
            throws JAXBException {
 +
        marshaller.setProperty(MarshallerProperties.JSON_VALUE_WRAPPER, "$");
 +
    }
 +
 +
}
 
</source>
 
</source>
 
</div>
 
</div>

Revision as of 16:19, 15 June 2012

MOXy JSON Provider

MOXy now includes an implementation (MOXyJsonProvider) that can be used directly or extended to make the integration even easier.

Using MOXyJsonProvider

Default Behaviour

You can use a JAX-RS Application class to specify that MOXyJsonProvider should be used with your JAX-RS application.

package org.example;
 
import java.util.*;
import javax.ws.rs.core.Application;
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;
 
public class CustomerApplication  extends Application {
 
    @Override
    public Set<Class<?>> getClasses() {
        HashSet<Class<?>> set = new HashSet<Class<?>>(2);
        set.add(MOXyJsonProvider.class);
        set.add(CustomerService.class);
        return set;
    }
 
}

Configuration Options

You can also use a JAX-RS Application class to specify an instance of MOXyJsonProvider to be used with your JAX-RS application. This approach allows you customize the different configuration options offered by the MOXyJsonProvider.

package org.example;
 
import java.util.*;
import javax.ws.rs.core.Application;
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;
 
public class CustomerApplication  extends Application {
 
    @Override
    public Set<Class<?>> getClasses() {
        HashSet<Class<?>> set = new HashSet<Class<?>>(1);
        set.add(ExampleService.class);
        return set;
    }
 
    @Override
    public Set<Object> getSingletons() {
        MOXyJsonProvider moxyJsonProvider = new MOXyJsonProvider();
 
        moxyJsonProvider.setAttributePrefix("@");
        moxyJsonProvider.setFormattedOutput(true);
        moxyJsonProvider.setIncludeRoot(true);
        moxyJsonProvider.setMarshalEmptyCollections(false);
        moxyJsonProvider.setValueWrapper("$");
 
        Map<String, String> namespacePrefixMapper = new HashMap<String, String>(1);
        namespacePrefixMapper.put("http://www.example.org/customer", "cust");
        moxyJsonProvider.setNamespacePrefixMapper(namespacePrefixMapper);
        moxyJsonProvider.setNamespaceSeparator(':');
 
        HashSet<Object> set = new HashSet<Object>(1);
        set.add(moxyJsonProvider);
        return set;
    }
 
}

WEB-INF/web.xml

A web.xml file is used to configure the Application class:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <servlet>
        <servlet-name>Jersey Web Application</servlet-name>
        <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer
        </servlet-class>
        <load-on-startup>1</load-on-startup>
        <init-param>
            <param-name>javax.ws.rs.Application</param-name>
            <param-value>org.example.CustomerApplication</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey Web Application</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
    <persistence-context-ref>
        <persistence-context-ref-name>persistence/em</persistence-context-ref-name>
        <persistence-unit-name>CustomerService</persistence-unit-name>
    </persistence-context-ref>
</web-app>

Extending MOXyJsonProvider

You can also extend MOXyJsonProvider to create your own MessageBodyReader/MessageBodyWriter. The preReadFrom and preWriteTo methods can be overridden to customize the Unmarshaller/Marshaller that will be used by MOXy.

package org.example;
 
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
 
import javax.ws.rs.*;
import javax.ws.rs.core.*;
import javax.ws.rs.ext.Provider;
import javax.xml.bind.*;
 
import org.eclipse.persistence.jaxb.MarshallerProperties;
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;
 
@Provider
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class CustomerJSONProvider extends MOXyJsonProvider {
 
    @Override
    public boolean isReadable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        return getDomainClass(genericType) == Customer.class;
    }
 
    @Override
    public boolean isWriteable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        return isReadable(type, genericType, annotations, mediaType);
    }
 
    @Override
    protected void preReadFrom(Class<Object> type, Type genericType,
            Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> httpHeaders,
            Unmarshaller unmarshaller) throws JAXBException {
        unmarshaller.setProperty(MarshallerProperties.JSON_VALUE_WRAPPER, "$");
    }
 
    @Override
    protected void preWriteTo(Object object, Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> httpHeaders, Marshaller marshaller)
            throws JAXBException {
        marshaller.setProperty(MarshallerProperties.JSON_VALUE_WRAPPER, "$");
    }
 
}