Chapter 360. XML JSon DataFormat (deprecated)

The XML JSon dataformat supports 13 options which are listed below.

Within the <dataFormats> block, simply configure an xmljson element with unique IDs:

<dataFormats>
    <xmljson id="xmljson"/>
    <xmljson id="xmljsonWithOptions" forceTopLevelObject="true" trimSpaces="true" rootName="newRoot" skipNamespaces="true"
             removeNamespacePrefixes="true" expandableProperties="d e"/>
</dataFormats>

Then you simply refer to the data format object within your <marshal /> and <unmarshal /> DSLs:

<route>
    <from uri="direct:marshal"/>
    <marshal ref="xmljson"/>
    <to uri="mock:json" />
</route>

<route>
    <from uri="direct:unmarshalWithOptions"/>
    <unmarshal ref="xmljsonWithOptions"/>
    <to uri="mock:xmlWithOptions"/>
</route>

Enabling XML DSL autocompletion for this component is easy: just refer to the appropriate Schema locations, depending on whether you’re using Spring or Blueprint DSL. Remember that this data format is available from Camel 2.10 onwards, so only schemas from that version onwards will include these new XML elements and attributes.

The syntax with Blueprint is identical to that of the Spring DSL. Just ensure the correct namespaces and schemaLocations are in use.

XML has namespaces to fully qualify elements and attributes; JSON doesn’t. You need to take this into account when performing XML-JSON conversions.

To bridge the gap, Json-lib has an option to bind namespace declarations in the form of prefixes and namespace URIs to XML output elements while unmarshalling (i.e. converting from JSON to XML). For example, provided the following JSON string:

{ "pref1:a": "value1", "pref2:b": "value2" }

you can ask Json-lib to output namespace declarations on elements pref1:a and pref2:b to bind the prefixes pref1 and pref2 to specific namespace URIs.

To use this feature, simply create XmlJsonDataFormat.NamespacesPerElementMapping objects and add them to the namespaceMappings option (which is a List).

The XmlJsonDataFormat.NamespacesPerElementMapping holds an element name and a Map of [prefix ⇒ namespace URI]. To facilitate mapping multiple prefixes and namespace URIs, the NamespacesPerElementMapping(String element, String pipeSeparatedMappings) constructor takes a String-based pipe-separated sequence of [prefix, namespaceURI] pairs in the following way: |ns2|http://camel.apache.org/personalData|ns3|http://camel.apache.org/personalData2|.

In order to define a default namespace, just leave the corresponding key field empty: |ns1|http://camel.apache.org/test1||http://camel.apache.org/default|.

Binding namespace declarations to an element name = empty string will attach those namespaces to the root element.

The full code would look like that:

XmlJsonDataFormat namespacesFormat = new XmlJsonDataFormat();
List<XmlJsonDataFormat.NamespacesPerElementMapping> namespaces = new ArrayList<XmlJsonDataFormat.NamespacesPerElementMapping>();
namespaces.add(new XmlJsonDataFormat.
                       NamespacesPerElementMapping("", "|ns1|http://camel.apache.org/test1||http://camel.apache.org/default|"));
namespaces.add(new XmlJsonDataFormat.
                       NamespacesPerElementMapping("surname", "|ns2|http://camel.apache.org/personalData|" +
                           "ns3|http://camel.apache.org/personalData2|"));
namespacesFormat.setNamespaceMappings(namespaces);
namespacesFormat.setRootElement("person");

And you can achieve the same in Spring DSL.

{ "name": "Raul", "surname": "Kripalani", "f": true, "g": null}

<person xmlns="http://camel.apache.org/default" xmlns:ns1="http://camel.apache.org/test1">
    <f>true</f>
    <g null="true"/>
    <name>Raul</name>
    <surname xmlns:ns2="http://camel.apache.org/personalData" xmlns:ns3="http://camel.apache.org/personalData2">Kripalani</surname>
</person>

To use the XmlJson dataformat in your camel routes you need to add the following dependency to your pom:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-xmljson</artifactId>
  <version>x.x.x</version>
  <!-- Use the same version as camel-core, but remember that this component is only available from 2.10 onwards -->
</dependency>

<!-- And also XOM must be included. XOM cannot be included by default due to an incompatible
license with ASF; so add this manually -->
<dependency>
  <groupId>xom</groupId>
  <artifactId>xom</artifactId>
  <version>1.2.5</version>
</dependency>