Snippet

Injecting Auth Headers with RestTemplate Interceptors

Interceptors in RestTemplate allow you to apply logic to all outgoing HTTP requests globally. This is ideal for adding authentication tokens, logging request payloads, or handling custom error logic without repeating it at every call site.

snippet.java

java

public class AuthInterceptor implements ClientHttpRequestInterceptor {
    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        request.getHeaders().add("Authorization", "Bearer " + getToken());
        return execution.execute(request, body);
    }
    private String getToken() { return "secret-token"; }
}
 
@Bean
public RestTemplate restTemplate() {
    RestTemplate restTemplate = new RestTemplate();
    restTemplate.setInterceptors(Collections.singletonList(new AuthInterceptor()));
    return restTemplate;
}

spring

Breakdown

ClientHttpRequestInterceptor

The interface used to intercept and modify outbound client-side HTTP requests.

execution.execute(request, body)

Continues the request chain after the interceptor logic is applied.

setInterceptors(...)

Registers the list of interceptors to be used by the RestTemplate instance.

Previous snippet Next snippet

More Intermediate Java exercises →

Injecting Auth Headers with RestTemplate Interceptors

Related