Basic authentication for REST API using spring restTemplate

Question

I am completely new in RestTemplate and basically in the REST APIs also. I want to retrieve some data in my application via Jira REST API, but getting back 401 Unauthorised. Found and article on jira rest api documentation but don't really know how to rewrite this into java as the example uses the command line way with curl. I would appreciate any suggestion or advice how to rewrite:

curl -D- -X GET -H "Authorization: Basic ZnJlZDpmcmVk" -H "Content-Type: application/json" "http://kelpie9:8081/rest/api/2/issue/QA-31"

into java using spring rest template. Where the ZnJlZDpmcmVk is a base64 encoded string of username:password. Thank you very much.

Answer 1

Taken from the example on this site, I think this would be the most natural way of doing it, by filling in the header value and passing the header to the template.

This is to fill in the header Authorization:

String plainCreds = "willie:p@ssword";
byte[] plainCredsBytes = plainCreds.getBytes();
byte[] base64CredsBytes = Base64.encodeBase64(plainCredsBytes);
String base64Creds = new String(base64CredsBytes);

HttpHeaders headers = new HttpHeaders();
headers.add("Authorization", "Basic " + base64Creds);

And this is to pass the header to the REST template:

HttpEntity<String> request = new HttpEntity<String>(headers);
ResponseEntity<Account> response = restTemplate.exchange(url, HttpMethod.GET, request, Account.class);
Account account = response.getBody();

Answer 2

You may use spring-boot RestTemplateBuilder

@Bean
RestOperations rest(RestTemplateBuilder restTemplateBuilder) {
    return restTemplateBuilder.basicAuthentication("user", "password").build();
}

See documentation

(before SB 2.1.0 it was #basicAuthorization)

Answer 3

(maybe) the easiest way without importing spring-boot.

restTemplate.getInterceptors().add(new BasicAuthorizationInterceptor("user", "password"));

Answer 4

Reference Spring Boot's TestRestTemplate implementation as follows:

https://github.com/spring-projects/spring-boot/blob/master/spring-boot/src/main/java/org/springframework/boot/test/TestRestTemplate.java

Especially, see the addAuthentication() method as follows:

private void addAuthentication(String username, String password) {
    if (username == null) {
        return;
    }
    List<ClientHttpRequestInterceptor> interceptors = Collections
            .<ClientHttpRequestInterceptor> singletonList(new BasicAuthorizationInterceptor(
                    username, password));
    setRequestFactory(new InterceptingClientHttpRequestFactory(getRequestFactory(),
            interceptors));
}

Similarly, you can make your own RestTemplate easily

by inheritance like TestRestTemplate as follows:

https://github.com/izeye/samples-spring-boot-branches/blob/rest-and-actuator-with-security/src/main/java/samples/springboot/util/BasicAuthRestTemplate.java

Answer 5

As of Spring 5.1 you can use HttpHeaders.setBasicAuth

Create Basic Authorization header:

String username = "willie";
String password = ":p@ssword";
HttpHeaders headers = new HttpHeaders();
headers.setBasicAuth(username, password);
...other headers goes here...

Pass the headers to the RestTemplate:

HttpEntity<String> request = new HttpEntity<String>(headers);
ResponseEntity<Account> response = restTemplate.exchange(url, HttpMethod.GET, request, Account.class);
Account account = response.getBody();

Documentation: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/HttpHeaders.html#setBasicAuth-java.lang.String-java.lang.String-

Answer 6

Instead of instantiating as follows:

TestRestTemplate restTemplate = new TestRestTemplate();

Just do it like this:

TestRestTemplate restTemplate = new TestRestTemplate(user, password);

It works for me, I hope it helps!