PreemptiveAuthorizer (Concurrent Processing Framework Client Java API 6.1.x-SNAPSHOT API)

java.lang.Object
- net.oauth.client.httpclient4.PreemptiveAuthorizer

All Implemented Interfaces:

org.apache.http.HttpRequestInterceptor
```
public class PreemptiveAuthorizer
extends Object
implements org.apache.http.HttpRequestInterceptor
```
An interceptor that initiates authorization without waiting for a challenge from the server. This avoids a response/request exchange (for the challenge), but it doesn't give the server a chance to select the authorization scheme or realm.
To make this work:
- In your HttpContext attributes, set a list of preferred auth scheme names.
- In your DigestHttpClient auth schemes, register an AuthSchemeFactory for at least one of those schemes.
- In your DigestHttpClient credentials provider, set Credentials for an AuthScope that will match your request.
- In your DigestHttpClient params, register any parameters the AuthSchemeFactory requires.
- In your DigestHttpClient, add an instance of this interceptor.
Here's an example using OAuth:
```
 context = new BasicHttpContext();
 context.setAttribute(ClientContext.AUTH_SCHEME_PREF,
   Arrays.asList(OAuthSchemeFactory.SCHEME_NAME));
 client = new DefaultHttpClient();
 client.getAuthSchemes().register(OAuthSchemeFactory.SCHEME_NAME,
   new OAuthSchemeFactory());
 client.getCredentialsProvider().setCredentials(new AuthScope("server.com", 80),
   new OAuthCredentials(accessor));
 client.getParams().setParameter(OAuthSchemeFactory.DEFAULT_REALM,
   ProtectedResource.REALM);
 client.addRequestInterceptor(new PreemptiveAuthorizer(), 0);
 
```
Author:

John Kristian

Constructor Summary

Constructors
Constructor Description

PreemptiveAuthorizer()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`process(org.apache.http.HttpRequest request, org.apache.http.protocol.HttpContext context)`	If no auth scheme has been selected for the given context, consider each of the preferred auth schemes and select the first one for which an AuthScheme and matching Credentials are available.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - PreemptiveAuthorizer
```
public PreemptiveAuthorizer()
```
- Method Detail
  - process
```
public void process(org.apache.http.HttpRequest request,
                    org.apache.http.protocol.HttpContext context)
             throws org.apache.http.HttpException,
                    IOException
```
    If no auth scheme has been selected for the given context, consider each of the preferred auth schemes and select the first one for which an AuthScheme and matching Credentials are available.
    
    Specified by:
    
    process in interface org.apache.http.HttpRequestInterceptor
    
    Throws:
    
    org.apache.http.HttpException
    
    IOException