Chapter 347. Thrift DataFormat

The Thrift dataformat supports 3 options, which are listed below.

The component supports 7 options, which are listed below.

ND

It’s possible to parse JSON message to convert it to the Thrift format and unparse it back using native util converter. To use this option, set contentTypeFormat value to 'json' or call thrift with second parameter. If default instance is not specified, always use native binary Thrift format. The simple JSON format is write-only (marshal) and produces a simple output format suitable for parsing by scripting languages. The sample code shows below:

from("direct:marshal")
    .unmarshal()
    .thrift("org.apache.camel.dataformat.thrift.generated.Work", "json")
    .to("mock:reverse");

This quick overview of how to use Thrift. For more detail see the complete tutorial

The first step is to define the format for the body of your exchange. This is defined in a .thrift file as so:

tutorial.thrift

namespace java org.apache.camel.dataformat.thrift.generated

enum Operation {
  ADD = 1,
  SUBTRACT = 2,
  MULTIPLY = 3,
  DIVIDE = 4
}

struct Work {
  1: i32 num1 = 0,
  2: i32 num2,
  3: Operation op,
  4: optional string comment,
}

The Apache Thrift provides a compiler which will generate the Java classes for the format we defined in our .thrift file.

You can also run the compiler for any additional supported languages you require manually.

thrift -r --gen java -out ../java/ ./tutorial-dataformat.thrift

This will generate separate Java class for each type defined in .thrift file, i.e. struct or enum. The generated classes implement org.apache.thrift.TBase which is required by the serialization mechanism. For this reason it important that only these classes are used in the body of your exchanges. Camel will throw an exception on route creation if you attempt to tell the Data Format to use a class that does not implement org.apache.thrift.TBase.

You can use create the ThriftDataFormat instance and pass it to Camel DataFormat marshal and unmarshal API like this.

   ThriftDataFormat format = new ThriftDataFormat(new Work());

   from("direct:in").marshal(format);
   from("direct:back").unmarshal(format).to("mock:reverse");

Or use the DSL thrift() passing the unmarshal default instance or default instance class name like this.

   // You don't need to specify the default instance for the thrift marshaling
   from("direct:marshal").marshal().thrift();
   from("direct:unmarshalA").unmarshal()
       .thrift("org.apache.camel.dataformat.thrift.generated.Work")
       .to("mock:reverse");

   from("direct:unmarshalB").unmarshal().thrift(new Work()).to("mock:reverse");

The following example shows how to use Thrift to unmarshal using Spring configuring the thrift data type

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="direct:start"/>
    <unmarshal>
      <thrift instanceClass="org.apache.camel.dataformat.thrift.generated.Work" />
    </unmarshal>
    <to uri="mock:result"/>
  </route>
</camelContext>

To use Thrift in your camel routes you need to add the a dependency on camel-thrift which implements this data format.

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-thrift</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>