if (message.type === 'utf8') {
   console.log(message.utf8Data);
 }
if (message.type === 'binary') {
    dataStream.write(message.binaryData);
 }

dataStream.write(message.binaryData);

console.log(message.utf8Data);

try {
    // throw an exception if message type is not utf-8
    if (message.type !== 'utf8') {
        throw "NotUtf8Encoding"
    }
    // this will not be reached if the exception is thrown
    console.log(message.utf8Data);
} catch(err) { // catch the exception thrown above
    if (message.type === 'binary') {
        dataStream.write(message.binaryData);
    }
    /* Do whatever else...*/
}