Basic Authentication with RestTemplate - compilation error - The constructor HttpClient() is not visible

问题

trying to add basic auth to restTemplate

problem I encounter is that i cant initialize : (with both the imports in the code snippet)

HttpClient client = new HttpClient();

This code resolves in a compilation error (with no suggestion available from eclipse to fix this issue)

1) what is the problem ?

2) Am i importing the wrong class ?

my code snippet :

import org.apache.http.client.HttpClient;
//OR (not together)
import sun.net.www.http.HttpClient;


HttpClient client = new HttpClient(); //this line dosent compile
UsernamePasswordCredentials credentials =
new UsernamePasswordCredentials("USERNAME","PASS");
client.getState().setCredentials(
  new AuthScope("www.example.com", 9090, AuthScope.ANY_REALM),
  credentials);
CommonsClientHttpRequestFactory commons =
     new CommonsClientHttpRequestFactory(client);

RestTemplate template = new RestTemplate(commons);
SomeObject result = template.getForObject(
     "http://www.example.com:9090/",SomeObject.class
 );

Running this get the Exception :

> failed due to an unhandled exception: java.lang.Error: Unresolved
> compilation problems:     The constructor HttpClient() is not visible
>   The method getState() is undefined for the type HttpClient
>   CommonsClientHttpRequestFactory cannot be resolved to a type
>   CommonsClientHttpRequestFactory cannot be resolved to a type
>   SomeObject cannot be resolved to a type     The method
> getForObject(String, Class<SomeObject>, Object...) from the type
> RestTemplate refers to the missing type SomeObject    SomeObject cannot
> be resolved to a type

回答1:

in the end its much easier to run Basic Authentication using :

restTemplate.exchange()

and not

restTemplate.getForObject()

my code snippet :

private HttpHeaders createHeaders(final String username, final String password ){
    HttpHeaders headers =  new HttpHeaders(){
          {
             String auth = username + ":" + password;
             byte[] encodedAuth = Base64.encodeBase64(
                auth.getBytes(Charset.forName("US-ASCII")) );
             String authHeader = "Basic " + new String( encodedAuth );
             set( "Authorization", authHeader );
          }
       };
       headers.add("Content-Type", "application/xml");
       headers.add("Accept", "application/xml");

       return headers;
}


    RestTemplate restTemplate = new RestTemplate();
    ResponseEntity<MyClass> response;
    httpHeaders = this.createHeaders("user", "pass");

    String url = "www.example.com"
    response = restTemplate.exchange(url, HttpMethod.GET, new HttpEntity<Object>(httpHeaders), MyClass.class);

and it works !

回答2:

If you use the Apache HttpClient, instantiate DefaultHttpClient, because HttpClient is just an interface:

HttpClient httpclient = new DefaultHttpClient();

See the documentation on using various authentication schemes with HttpClient here.

回答3:

We can use it in Spring boot in the below manner :

   @SpringBootApplication

public class Application implements CommandLineRunner{

private static final Logger log = LoggerFactory.getLogger(Application.class);

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

@Override
public void run(String... args) throws Exception {
    try{
    RestTemplate restTemplate = new RestTemplate();
    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders = this.createHeaders();
    ResponseEntity<String> response;
    response  = restTemplate.exchange("<url>",HttpMethod.GET,new HttpEntity<Object>(httpHeaders),String.class);
    log.info(response.toString());
    }
    catch(Exception e)
    {
        System.out.println("Exception"+e);
    }


}

private HttpHeaders createHeaders(){
    HttpHeaders headers =  new HttpHeaders(){
          {            
             set( "Authorization", "3ee140");
          }
       };

       return headers;
}

}

来源：https://stackoverflow.com/questions/15462128/basic-authentication-with-resttemplate-compilation-error-the-constructor-htt

标签

java

Spring

rest

http-headers

basic-authentication