Process compressed json request in Spring Boot Rest Controller - json

Question

I've been trying to process the RequestBody which is JSON data sent as GZIP. In my RestController I have the following method:
#RequestMapping(value = "/api/data", method = RequestMethod.POST)
public ResponseEntity<String> updateData(#RequestBody String data) {
System.out.println(data);
return new ResponseEntity(HttpStatus.CREATED);
}
The 'data' which is sent to the controller is JSON that is GZIP-ed and when I print it, it is all encoded. How can I decode/unzip this data?

Answer 1

In the end from different sources I scraped the answer. Here's an example:
#Component
public class GzipBodyDecompressFilter implements Filter {
#Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpServletResponse response = (HttpServletResponse) servletResponse;
request = new GzippedInputStreamWrapper((HttpServletRequest) servletRequest);
chain.doFilter(request, response);
}
final class GzippedInputStreamWrapper extends HttpServletRequestWrapper {
public static final String DEFAULT_ENCODING = "ISO-8859-1";
private byte[] bytes;
public GzippedInputStreamWrapper(final HttpServletRequest request) throws IOException {
super(request);
try {
final InputStream in = new GZIPInputStream(request.getInputStream());
bytes = IOUtils.toByteArray(in);
} catch (EOFException e) {
bytes = new byte[0];
}
}
#Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream sourceStream = new ByteArrayInputStream(bytes);
return new ServletInputStream() {
public int read() throws IOException {
return sourceStream.read();
}
#Override
public void setReadListener(ReadListener listener) {
// TODO Auto-generated method stub
}
#Override
public boolean isFinished() {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean isReady() {
// TODO Auto-generated method stub
return false;
}
public void close() throws IOException {
super.close();
sourceStream.close();
}
};
}
#Override
public Map getParameterMap() {
return super.getParameterMap();
}
}
}
doFilter method will be executed before it reaches controller, in which I can do anything to the body of the request (since I have access to ServletRequest), e.g. creating an implementation for HttpServletRequestWrapper where I unzip the content.