Http Message Converters with the Spring Framework. The Price of all Learn Spring Security course packages will permanently increase by 5. Friday GET ACCESS NOW1. Overview. This article describes how to Configure Http. Message. Converter in Spring. Simply put, message converters are used to marshall and unmarshall Java Objects to and from JSON, XML, etc over HTTP. Java deserialize example, read an Java object from file. A guide to configuring content negotiation in a Spring MVC application and on enabling and disabling the various available strategies. Read more The article shows the alternatives for returning image or other media with Spring MVC and discusses the pros and cons of each approach. Read more In this article we explore how to configure Spring REST mechanism to utilize binary data formats which we illustrate with Kryo. Moreover we show how to support multiple data formats with Google Protocol buffers. Read more 2. The Basics. Enable Web MVCThe Web Application needs to be configured with Spring MVC support one convenient and very customizable way to do this is to use the Enable. Web. Mvc annotation Enable. Web. Mvc. Component. Scan org. baeldung. Web. Config extends Web. Mvc. Configurer. Adapter. Note that this class extends Web. Mvc. Configurer. Adapter which will allow us to change the default list of Http Converters with our own. The Default Message Converters. Tk7.png' alt='Java Serialized Object Http Post' title='Java Serialized Object Http Post' />By default, the following Http. Message. Converters instances are pre enabled Byte. Array. Http. Message. Converter converts byte arrays. String. Http. Message. Converter converts Strings. Resource. Http. Message. Oracle Technology Network is the ultimate, complete, and authoritative source of technical information and learning about Java. Here is my another post about preparing for Java Interviews, this time we will take a look at 40 core Java questions from telephonic round of Java Programming. Complete Java Programming Bootcamp 10 Courses to Become a Java Master Design UIs with JavaFX, Utilize Design Patterns, Master Multithreading More. Basic Object Copying in Java. Let us Assume an object obj1, that contains two objects, containedObj1 and containedObj2. Converter converts org. Resource for any type of octet stream. Source. Http. Message. Converter converts javax. Source. Form. Http. Message. Converter converts form data tofrom a Multi. Value. Maplt String, String. Jaxb. 2Root. Element. Http. Message. Converter converts Java objects tofrom XML added only if JAXB2 is present on the classpathMapping. Jackson. 2Http. Message. Converter converts JSON added only if Jackson 2 is present on the classpathMapping. Jackson. Http. Message. Converter converts JSON added only if Jackson is present on the classpathAtom. Feed. Http. Message. Converter converts Atom feeds added only if Rome is present on the classpathRss. Channel. Http. Message. Converter converts RSS feeds added only if Rome is present on the classpath3. Client Server Communication JSON only. Intel Graphics Media Accelerator Driver Win7 64 Bit. High Level Content Negotiation. Each Http. Message. Converter implementation has one or several associated MIME Types. When receiving a new request, Spring will use of the Accept header to determine the media type that it needs to respond with. It will then try to find a registered converter that is capable of handling that specific media type and it will use it to convert the entity and send back the response. The process is similar for receiving a request which contains JSON information the framework will use  the Content Type header to determine the media type of the request body. It will then search for a Http. Message. Converter that can convert the body sent by the client to a Java Object. Lets clarify this with a quick example the Client sends a GET request to foos with the Accept header set to applicationjson to get all Foo resources as Jsonthe Foo Spring Controller is hit and returns the corresponding Foo Java entities. Spring then uses one of the Jackson message converters to marshall the entities to json. Lets now look at the specifics of how this works and how we should leverage the Response. Body and Request. Body annotations. Response. BodyResponse. Body on a Controller method indicates to Spring that the return value of the method is serialized directly to the body of the HTTP Response. As discussed above, the Accept header specified by the Client will be used to choose the appropriate Http Converter to marshall the entity. Lets look at a simple example Request. MappingmethodRequest. Method. GET, valuefoosid. Response. Body Foo find. By. IdPath. Variable long id. Service. getid. Now, the client will specify the Accept header to applicationjson in the request example curl command curl header Accept applicationjson. The Foo class public class Foo. String name. And the Http Response Body. Paul. 3. 3. Request. BodyRequest. Bodyis used on the argument of a Controller method it indicates to Spring that the body of the HTTP Request is deserialized to that particular Java entity. As discussed previously, the Content Type header specified by the Client will be used to determine the appropriate converter for this. Lets look at an example Request. MappingmethodRequest. Method. PUT, valuefoosid. Response. Body void update. Foo. Request. Body Foo foo, Path. Variable String id. Service. updatefoo. Now, lets consume this with a JSON object were specifying Content Type to be applicationjson curl i X PUT H Content Type applicationjson. We get back a 2. 00 OK a successful response HTTP1. OK. Server Apache Coyote1. Content Length 0. Date Fri, 1. 0 Jan 2. GMT4. Custom Converters Configuration. We can customize the message converters by extending the Web. Mvc. Configurer. Adapter class and overriding the configure. Message. Converters method Enable. Web. Mvc. Component. Scan org. baeldung. Web. Config extends Web. Mvc. Configurer. Adapter. Message. Converters. Listlt Http. Message. Converterlt converters. Converters. addcreate. Xml. Http. Message. Converter. message. Converters. addnew Mapping. Jackson. 2Http. Message. Converter. super. Message. Convertersconverters. Http. Message. Converterlt Object create. Xml. Http. Message. Converter. Marshalling. Http. Message. Converter xml. Converter. new Marshalling. Http. Message. Converter. XStream. Marshaller xstream. Marshaller new XStream. Marshaller. xml. Converter. Marshallerxstream. Marshaller. xml. Converter. Unmarshallerxstream. Marshaller. return xml. Converter. And here is the corresponding XML configuration lt UTF 8. XMLSchema instance. Location. http www. Mapping. Jackson. Http. Message. Converter. Marshalling. Http. Message. Converter. Marshaller. Marshaller. Marshaller classorg. XStream. Marshaller. Note that the XStream library now needs to be present on the classpath. Also be aware that by extending this support class, we are losing the default message converters which were previously pre registered we only have what we define. Lets go over this example we are creating a new converter the Marshalling. Http. Message. Converter and were using the Spring XStream support to configure it. This allows a great deal of flexibility since were working with the low level APIs of the underlying marshalling framework in this case XStream and we can configure that however we want. We can of course now do the same for Jackson by defining our own Mapping. Jackson. 2Http. Message. Converter we can now set a custom Object. Mapper on this converter and have it configured as we need to. In this case XStream was the selected marshallerunmarshaller implementation, but others like Castor. Marshaller can be used to refer to Spring api documentation for full list of available marshallers. At this point with XML enabled on the back end we can consume the API with XML Representations curl header Accept applicationxml. Using Springs Rest. Template with Http Message Converters.