BufferingClientHttpResponseWrapper.java

package de.dfki.nlp.io;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.util.FileCopyUtils;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Class that buffers the Client respone body, so it can be read multiple times.
 * Reimplementation of the same spring class - due to package privacy.
 */
public class BufferingClientHttpResponseWrapper implements ClientHttpRequestInterceptor {

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {

        // wrap the response
        return new WrappenClientHttpResponse(execution.execute(request, body));
    }

    private class WrappenClientHttpResponse implements ClientHttpResponse {

        private final ClientHttpResponse delegate;

        private byte[] bytes;

        private WrappenClientHttpResponse(ClientHttpResponse delegate) {
            this.delegate = delegate;
        }

        @Override
        public HttpStatus getStatusCode() throws IOException {
            return delegate.getStatusCode();
        }

        @Override
        public int getRawStatusCode() throws IOException {
            return delegate.getRawStatusCode();
        }

        @Override
        public String getStatusText() throws IOException {
            return delegate.getStatusText();
        }

        @Override
        public void close() {
            delegate.close();
        }

        @Override
        public InputStream getBody() throws IOException {
            if (bytes == null) {
                bytes = FileCopyUtils.copyToByteArray(delegate.getBody());
            }
            return new ByteArrayInputStream(bytes);
        }

        @Override
        public HttpHeaders getHeaders() {
            return delegate.getHeaders();
        }
    }

}