### Binary message validation

Binary message validation is not very easy to do especially when it comes to compare data with a given control message. As a tester you want to validate the binary content. In Citrus the way to compare binary message content is to use base64 String encoding. The binary data is encoded as base64 character sequence and there fore is comparable with an expected content.

The received message content does not have to be base64 encoded. Citrus is doing this conversion automatically before validation takes place. The binary data can be anything e.g. images, pdf or gzip content.

The default message validator for binary messages is active by default. Citrus will pick this message validator for all messages of type="binary_base64" . The default message validator implementation can be overwritten by placing a Spring bean with id defaultBinaryBase64MessageValidator to the Spring application context.

    <bean id="defaultBinaryBase64MessageValidator" class="com.consol.citrus.validation.text.BinaryBase64MessageValidator"/>

In the test case receiving action we tell Citrus to use binary base64 message validation.

    <receive endpoint="httpMessageEndpoint">
        <message type="binary_base64">
            <data>citrus:encodeBase64('Hello World!')</data>
        </message>
    </receive>

With the message format type type="binary_base64" Citrus performs the base64 character sequence validation. Incoming message content is automatically encoded as base64 String and compared to the expected data. This way we can make sure that the binary content is as expected.

By the way sending binary messages in Citrus is also very easy. Just use the type="binary" message type in the send operation. Citrus now converts the message payload to a binary stream as payload.

    <send endpoint="httpMessageEndpoint">
        <message type="binary">
            <data>Hello World!</data>
        </message>
    </send>

Base64 encoding is also supported in outbound messages. Just use the encodeBase64 function in Citrus. The result is a base64 encoded String as message payload.

    <send endpoint="httpMessageEndpoint">
        <message>
            <data>citrus:encodeBase64('Hello World!')</data>
        </message>
    </send>