Spring RestTemplate POST request is not working with HttpEntity<String>

Question

I am not able to call Spring RestTemplate with HttpEntity for POST request. My call to RestTemplate gives Base64 string in Postman but using my java implementation it gives following error:

java.lang.IllegalArgumentException: Illegal base64 character 5b
at java.util.Base64$Decoder.decode0(Base64.java:714)
at java.util.Base64$Decoder.decode(Base64.java:526)
at java.util.Base64$Decoder.decode(Base64.java:549)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

My implementation is:

final HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_XML);
            final HttpEntity<String> request = new HttpEntity<String>(searchRequestInput, headers);

            final ResponseEntity<String> postForEntity = restTemplate
                    .postForEntity(baseURL, request, String.class);

            String response = postForEntity.getBody();

I have tried following solutions, but it didn't work here

and this Also I have refered this

Answer 1

You can use HttpMessageConverter to request your restTemplate call for HttpEntity. Which can read and write Strings from the HTTP request and response.

From doc : By default, this converter supports all text media types (text/*), and writes with a Content-Type of text/plain.

You can try this by implementing StringHttpMessageConverter as below:

            final HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_XML);
            final HttpEntity<String> request = new HttpEntity<String>(searchRequestInput, headers);
            List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
            messageConverters.add(new StringHttpMessageConverter());
            restTemplate.setMessageConverters(messageConverters);

then call restTemplate with your request.

Answer 2

Try these utility methods:

public static <T> ResponseEntity<T> makeRestRequest(Object entity, String restUrl, HttpMethod method, Class<T> entityClass) {
    RestTemplate restTemplate = new RestTemplate();
    HttpEntity httpEntity = makeHttpEntity(entity);
    ResponseEntity<T> response = null;

    try {
        response = restTemplate.exchange(restUrl, method, httpEntity, entityClass);
    } catch (HttpClientErrorException e) {
        e.printStackTrace();
        return new ResponseEntity<>(e.getStatusCode());
    }

    return response;
}

public static <T> HttpEntity makeHttpEntity(T entity) {
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_XML);
    HttpEntity<T> httpEntity = new HttpEntity<>(entity, headers);
    return httpEntity;
}

Where in the these two method

• entity: your input object
• restUrl: your url
• HttpMethod: POST/GET
• entityClass: expected output object from the server

Answer 3

Please try with below code may it help you:

 final HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_XML);
    HttpEntity requestEntity;
    if (entity instanceof String) {
        requestEntity = new HttpEntity(headers);
    } else {
        requestEntity = new HttpEntity(searchRequestInput, headers);
    }
       try {
        String response  =  restTemplate.exchange(baseURL, HttpMethod.POST, requestEntity, String.class).getBody().toString());
       } catch (HttpServerErrorException | HttpClientErrorException e) {
        e.printStackTrace();
       }