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Getting the following exception while executing a GET against RestTemplate::exchange(). It's a pretty simple public endpoint. I have included the controller and the DTO. The exception notes 'content type [text/html]' - I have read in other articles that this may be related to error response in XML rather than a response JSON. I have looked a little deeper into exception with no success ... again a pretty simple GET endpoint ?? Any help is appreciated.
Public Endpoint
http://catfact.ninja/fact
Exception
2022-01-07 11:18:40.896 ERROR 22564 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in
context with path [] threw exception [Request processing failed; nested exception
is org.springframework.web.client.RestClientException: Error while extracting response
for type [class com.example.demo.CatDTO] and content type [text/html]; nested exception
is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unexpected character ('<' (code 60)): expected a valid value (JSON String, Number,
Array, Object or token 'null', 'true' or 'false'); nested exception
is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 60)):
expected a valid value (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
at [Source: (PushbackInputStream); line: 1, column: 2]] with root cause
DTO Class
public class CatDTO {
public String fact;
public int length;
Controller Class
package com.example.demo;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.http.*;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
@RestController
public class CatWebServiceController {
@Autowired
RestTemplate restTemplate;
String url = "http://catfact.ninja/fact";
@RequestMapping(value = "/cat")
public ResponseEntity<CatDTO> getCatFact() throws IOException {
System.out.println("Inside: CatWebServiceController::getCatFact()");
CatDTO catDTO;
String urlTemplate = UriComponentsBuilder.fromHttpUrl(url)
.encode()
.toUriString();
// Just a little test
ObjectMapper mapper = new ObjectMapper();
File f = new File("C:\\macgowan\\project\\test\\demo\\response.json");
CatDTO catDTO2 = mapper.readValue(f, CatDTO.class);
// Create the headers
HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
HttpEntity<String> entity = new HttpEntity<String>(headers);
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
//Add the Jackson Message converter
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
// Note: here we are making this converter to process any kind of response,
// not only application/*json, which is the default behaviour
converter.setSupportedMediaTypes(Collections.singletonList(MediaType.ALL));
messageConverters.add(converter);
restTemplate.setMessageConverters(messageConverters);
ResponseEntity<CatDTO> r = null;
r = restTemplate.exchange(urlTemplate,
HttpMethod.GET,
entity,
CatDTO.class);
System.out.println("Inside: It worked");
catch (HttpClientErrorException exc)
String errorMessage = exc.getResponseBodyAsString();
System.out.println("Inside: HttpClientErrorException");
catch (Exception exc)
String errorMessage = exc.getMessage();
System.out.println("Inside: Exception");
return r;
Spring Init
package com.example.demo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
public class DemoApplication
public static void main(String[] args)
SpringApplication.run(DemoApplication.class, args);
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
return builder.build();
Try https://catfact.ninja/fact instead of http://catfact.ninja/fact
What you are receiving is literally:
<head><title>301 Moved Permanently</title></head>
<center><h1>301 Moved Permanently</h1></center>
<hr><center>nginx/1.20.1</center>
</body>
</html>
so you where right that your error is related to a response in XML
to quickly find out, you can intercept the response:
restTemplate.getInterceptors().add((httpRequest, bytes, clientHttpRequestExecution) -> {
ClientHttpResponse response=clientHttpRequestExecution.execute(httpRequest, bytes);
String text = new String(response.getBody().readAllBytes(), StandardCharsets.UTF_8);
System.out.println(text);
return response;
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