Spring: Logging outgoing HTTP requests

Question

I am trying to log all the outgoing Http requests in my spring based web application. Is there is interceptor for this purpose? I want to log all outgoing the contents and headers before it leaves the application. I am using spring-ws to send SOAP requests. So basically, I want to log not only the SOAP request xml (as mentioned here How can I make Spring WebServices log all SOAP requests?) but the http request as a whole.

Answer 1

Intercept the request/response using a ClientInterceptor on the WebServiceGatewaySupport:

// soapClient extends WebServiceGatewaySupport
soapClient.setInterceptors(new ClientInterceptor[]{new ClientInterceptor() {
        @Override
        public boolean handleRequest(MessageContext messageContext) throws WebServiceClientException {
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            try {
                messageContext.getRequest().writeTo(os);
            } catch (IOException e) {
                throw new WebServiceIOException(e.getMessage(), e);
            }

            String request = new String(os.toByteArray());
            logger.trace("Request Envelope: " + request);
            return true;
        }

        @Override
        public boolean handleResponse(MessageContext messageContext) throws WebServiceClientException {
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            try {
                messageContext.getResponse().writeTo(os);
            } catch (IOException e) {
                throw new WebServiceIOException(e.getMessage(), e);
            }

            String response = new String(os.toByteArray());
            logger.trace("Response Envelope: " + response);
            return true;
        }
        ...

To get the headers as well you need an instance of TransportOutputStream. Unfortunately the class is abstract, so you need to subclass is. Here's how it might look:

class ByteArrayTransportOutputStream extends TransportOutputStream {

    private ByteArrayOutputStream outputStream;

    @Override
    public void addHeader(String name, String value) throws IOException {
        createOutputStream();
        String header = name + ": " + value + "\n";
        outputStream.write(header.getBytes());
    }

    public byte[] toByteArray() {
         return outputStream.toByteArray();
    }

    @Override
    protected OutputStream createOutputStream() throws IOException {
        if (outputStream == null) {
            outputStream = new ByteArrayOutputStream();
        }
        return outputStream;
    }
}