Ce contenu n'est pas disponible dans la langue sélectionnée.

17.4. JAXB and JSON provider

RESTEasy lets you marshal JAXB annotated POJOs to and from JSON with the Jettison JSON library. You can find more information about Jettison at http://jettison.codehaus.org/.

Jettison has two mapping formats: the default Jettison Mapped Convention format, and BadgerFish.

For example, consider this JAXB class:

@XmlRootElement(name = "book")
public class Book {

   private String author;
   private String ISBN;
   private String title;

   public Book() {
   }

   public Book(String author, String ISBN, String title) {
      this.author = author;
      this.ISBN = ISBN;
      this.title = title;
   }

   @XmlElement
   public String getAuthor() {
      return author;
   }

   public void setAuthor(String author) {
      this.author = author;
   }

   @XmlElement
   public String getISBN() {
      return ISBN;
   }

   public void setISBN(String ISBN) {
      this.ISBN = ISBN;
   }

   @XmlAttribute
   public String getTitle() {
      return title;
   }

   public void setTitle(String title) {
      this.title = title;
   }
}

@XmlRootElement(name = "book")
public class Book {

   private String author;
   private String ISBN;
   private String title;

   public Book() {
   }

   public Book(String author, String ISBN, String title) {
      this.author = author;
      this.ISBN = ISBN;
      this.title = title;
   }

   @XmlElement
   public String getAuthor() {
      return author;
   }

   public void setAuthor(String author) {
      this.author = author;
   }

   @XmlElement
   public String getISBN() {
      return ISBN;
   }

   public void setISBN(String ISBN) {
      this.ISBN = ISBN;
   }

   @XmlAttribute
   public String getTitle() {
      return title;
   }

   public void setTitle(String title) {
      this.title = title;
   }
}

Copy to Clipboard

Toggle word wrap

The JAXB Book class would be marshalled to JSON using the BadgerFish Convention:

 {"book":
    {
       "@title":"EJB 3.0",
       "author":{"$":"Bill Burke"},
       "ISBN":{"$":"596529260"}
    }
 }

 {"book":
    {
       "@title":"EJB 3.0",
       "author":{"$":"Bill Burke"},
       "ISBN":{"$":"596529260"}
    }
 }

Copy to Clipboard

Toggle word wrap

Element values are associated with a map. To find the value of the element, you must access the $ variable. You could access the book like this, in JavaScript:

 var data = eval("(" + xhr.responseText + ")");
 document.getElementById("zone").innerHTML = data.book.@title;
 document.getElementById("zone").innerHTML += data.book.author.$;

 var data = eval("(" + xhr.responseText + ")");
 document.getElementById("zone").innerHTML = data.book.@title;
 document.getElementById("zone").innerHTML += data.book.author.$;

Copy to Clipboard

Toggle word wrap

To use the BadgerFish Convention you must use the @org.jboss.resteasy.annotations.providers.jaxb.json.BadgerFish annotation either on the JAXB class you are marshalling or unmarshalling, or on the JAX-RS resource method or parameter:

 @BadgerFish
 @XmlRootElement(name = "book")
 public class Book {...}

 @BadgerFish
 @XmlRootElement(name = "book")
 public class Book {...}

Copy to Clipboard

Toggle word wrap

To return a book on the JAX-RS method without polluting your JAXB classes with RESTEasy annotations, you can add the annotation to the JAX-RS method instead:

 @BadgerFish
 @GET
 public Book getBook(...) {...}

 @BadgerFish
 @GET
 public Book getBook(...) {...}

Copy to Clipboard

Toggle word wrap

If your input is a Book, place it on the parameter:

 @POST
 public void newBook(@BadgerFish Book book) {...}

 @POST
 public void newBook(@BadgerFish Book book) {...}

Copy to Clipboard

Toggle word wrap

The default Jettison Mapped Convention returns the following JSON:

 { "book" :
      {
         "@title":"EJB 3.0",
         "author":"Bill Burke",
         "ISBN":596529260
       }
 }

 { "book" :
      {
         "@title":"EJB 3.0",
         "author":"Bill Burke",
         "ISBN":596529260
       }
 }

Copy to Clipboard

Toggle word wrap

Note that title is prefixed with the @ character. Unlike the BadgerFish convention, this does not represent the value of element text, which makes it simpler (and a sensible default). To access this in JavaScript:

 var data = eval("(" + xhr.responseText + ")");
 document.getElementById("zone").innerHTML = data.book.@title;
 document.getElementById("zone").innerHTML += data.book.author;

 var data = eval("(" + xhr.responseText + ")");
 document.getElementById("zone").innerHTML = data.book.@title;
 document.getElementById("zone").innerHTML += data.book.author;

Copy to Clipboard

Toggle word wrap

The Mapped Convention lets you adjust the JAXB mapping with the @org.jboss.resteasy.annotations.providers.jaxb.json.Mapped annotation. With this, you can provide an XML namespace to JSON namespace mapping. For example, if you define your JAXB namespace within your package-info.java class like so:

 @javax.xml.bind.annotation.XmlSchema(namespace="http://jboss.org/books")
 package org.jboss.resteasy.test.books;

 @javax.xml.bind.annotation.XmlSchema(namespace="http://jboss.org/books")
 package org.jboss.resteasy.test.books;

Copy to Clipboard

Toggle word wrap

You must define a JSON-to-XML namespace mapping, or you will receive an exception:

java.lang.IllegalStateException: Invalid JSON namespace:
  http://jboss.org/books
at org.codehaus.jettison.mapped.MappedNamespaceConvention
  .getJSONNamespace(MappedNamespaceConvention.java:151)
at org.codehaus.jettison.mapped.MappedNamespaceConvention
  .createKey(MappedNamespaceConvention.java:158)
at org.codehaus.jettison.mapped.MappedXMLStreamWriter
  .writeStartElement(MappedXMLStreamWriter.java:241)

java.lang.IllegalStateException: Invalid JSON namespace:
  http://jboss.org/books
at org.codehaus.jettison.mapped.MappedNamespaceConvention
  .getJSONNamespace(MappedNamespaceConvention.java:151)
at org.codehaus.jettison.mapped.MappedNamespaceConvention
  .createKey(MappedNamespaceConvention.java:158)
at org.codehaus.jettison.mapped.MappedXMLStreamWriter
  .writeStartElement(MappedXMLStreamWriter.java:241)

Copy to Clipboard

Toggle word wrap

The @Mapped annotation fixes this problem. Place the @Mapped annotation on your JAXB classes, your JAX-RS resource method, or on the parameter that you are unmarshalling.

 import org.jboss.resteasy.annotations.providers.jaxb.json.Mapped;
 import org.jboss.resteasy.annotations.providers.jaxb.json.XmlNsMap;

 ...

@GET
@Produces("application/json")
@Mapped(namespaceMap = {
        @XmlNsMap(namespace = "http://jboss.org/books", jsonName = "books")
})
public Book get() {...}

 import org.jboss.resteasy.annotations.providers.jaxb.json.Mapped;
 import org.jboss.resteasy.annotations.providers.jaxb.json.XmlNsMap;

 ...

@GET
@Produces("application/json")
@Mapped(namespaceMap = {
        @XmlNsMap(namespace = "http://jboss.org/books", jsonName = "books")
})
public Book get() {...}

Copy to Clipboard

Toggle word wrap

You can also force @XmlAttributes to be marshalled as XMLElements.

            @Mapped(attributeAsElements={"title"})
            @XmlRootElement(name = "book")
            public class Book {...}

            @Mapped(attributeAsElements={"title"})
            @XmlRootElement(name = "book")
            public class Book {...}

Copy to Clipboard

Toggle word wrap

To return a book on the JAX-RS method without polluting your JAXB classes with RESTEasy annotations, add the annotation to the JAX-RS method:

            @Mapped(attributeAsElements={"title"})
            @GET
            public Book getBook(...) {...}

            @Mapped(attributeAsElements={"title"})
            @GET
            public Book getBook(...) {...}

Copy to Clipboard

Toggle word wrap

If your input is a Book, place it on the parameter:

 @POST
 public void newBook(@Mapped(attributeAsElements={"title"}) Book book) {...}

 @POST
 public void newBook(@Mapped(attributeAsElements={"title"}) Book book) {...}

Copy to Clipboard

Toggle word wrap

Ce contenu n'est pas disponible dans la langue sélectionnée.

17.4. JAXB and JSON provider

Apprendre

Essayez, achetez et vendez

Communautés

À propos de la documentation Red Hat

Rendre l’open source plus inclusif

À propos de Red Hat

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links