@Test
public void payloadMaxLength() throws Exception {
	filter.setIncludePayload(true);
	filter.setMaxPayloadLength(3);

	final MockHttpServletRequest request = new MockHttpServletRequest("POST", "/hotels");
	MockHttpServletResponse response = new MockHttpServletResponse();

	final byte[] requestBody = "Hello World".getBytes(StandardCharsets.UTF_8);
	request.setContent(requestBody);

	FilterChain filterChain = (filterRequest, filterResponse) -> {
		((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
		byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
		assertArrayEquals(requestBody, buf);
		ContentCachingRequestWrapper wrapper =
				WebUtils.getNativeRequest(filterRequest, ContentCachingRequestWrapper.class);
		assertArrayEquals("Hel".getBytes(StandardCharsets.UTF_8), wrapper.getContentAsByteArray());
	};

	filter.doFilter(request, response, filterChain);

	assertNotNull(filter.afterRequestMessage);
	assertTrue(filter.afterRequestMessage.contains("Hel"));
	assertFalse(filter.afterRequestMessage.contains("Hello World"));
}
 

@Test
public void payloadMaxLength() throws Exception {
	filter.setIncludePayload(true);
	filter.setMaxPayloadLength(3);

	final MockHttpServletRequest request = new MockHttpServletRequest("POST", "/hotels");
	MockHttpServletResponse response = new MockHttpServletResponse();

	final byte[] requestBody = "Hello World".getBytes("UTF-8");
	request.setContent(requestBody);

	FilterChain filterChain = new FilterChain() {
		@Override
		public void doFilter(ServletRequest filterRequest, ServletResponse filterResponse)
				throws IOException, ServletException {
			((HttpServletResponse) filterResponse).setStatus(HttpServletResponse.SC_OK);
			byte[] buf = FileCopyUtils.copyToByteArray(filterRequest.getInputStream());
			assertArrayEquals(requestBody, buf);
			ContentCachingRequestWrapper wrapper =
					WebUtils.getNativeRequest(filterRequest, ContentCachingRequestWrapper.class);
			assertArrayEquals("Hel".getBytes("UTF-8"), wrapper.getContentAsByteArray());
		}
	};

	filter.doFilter(request, response, filterChain);

	assertNotNull(filter.afterRequestMessage);
	assertTrue(filter.afterRequestMessage.contains("Hel"));
	assertFalse(filter.afterRequestMessage.contains("Hello World"));
}
 

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException {
    if (!StringUtils.isEmpty(request.getContentType())
        && MediaType.APPLICATION_JSON.isCompatibleWith(MediaType.valueOf(request.getContentType()))) {
        chain.doFilter(new ContentCachingRequestWrapper((HttpServletRequest)request), response);
    } else {
        chain.doFilter(request, response);
    }
}
 

public static String readPayload(final HttpServletRequest request) throws IOException {
    String payloadData = null;
    ContentCachingRequestWrapper contentCachingRequestWrapper = WebUtils.getNativeRequest(request, ContentCachingRequestWrapper.class);
    if (null != contentCachingRequestWrapper) {
        byte[] buf = contentCachingRequestWrapper.getContentAsByteArray();
        if (buf.length > 0) {
            payloadData = new String(buf, 0, buf.length, contentCachingRequestWrapper.getCharacterEncoding());
        }
    }
    return payloadData;
}