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AbstractAuthenticationHandler.javaAPI DocAndroid 1.5 API6276Wed May 06 22:41:10 BST 2009org.apache.http.impl.client

AbstractAuthenticationHandler

public abstract class AbstractAuthenticationHandler extends Object implements AuthenticationHandler
author
Oleg Kalnichevski

Fields Summary
private final Log
log
private static final List
DEFAULT_SCHEME_PRIORITY
Constructors Summary
public AbstractAuthenticationHandler()

    
      
        super();
Methods Summary
protected java.util.ListgetAuthPreferences()

        return DEFAULT_SCHEME_PRIORITY;
protected java.util.MapparseChallenges(org.apache.http.Header[] headers)

        
        Map<String, Header> map = new HashMap<String, Header>(headers.length);
        for (Header header : headers) {
            CharArrayBuffer buffer;
            int pos;
            if (header instanceof FormattedHeader) {
                buffer = ((FormattedHeader) header).getBuffer();
                pos = ((FormattedHeader) header).getValuePos();
            } else {
                String s = header.getValue();
                if (s == null) {
                    throw new MalformedChallengeException("Header value is null");
                }
                buffer = new CharArrayBuffer(s.length());
                buffer.append(s);
                pos = 0;
            }
            while (pos < buffer.length() && HTTP.isWhitespace(buffer.charAt(pos))) {
                pos++;
            }
            int beginIndex = pos;
            while (pos < buffer.length() && !HTTP.isWhitespace(buffer.charAt(pos))) {
                pos++;
            }
            int endIndex = pos;
            String s = buffer.substring(beginIndex, endIndex);
            map.put(s.toLowerCase(Locale.ENGLISH), header);
        }
        return map;
public org.apache.http.auth.AuthSchemeselectScheme(java.util.Map challenges, org.apache.http.HttpResponse response, org.apache.http.protocol.HttpContext context)

        
        AuthSchemeRegistry registry = (AuthSchemeRegistry) context.getAttribute(
                ClientContext.AUTHSCHEME_REGISTRY);
        if (registry == null) {
            throw new IllegalStateException("AuthScheme registry not set in HTTP context");
        }
        
        List<?> authPrefs = (List<?>) context.getAttribute(
                ClientContext.AUTH_SCHEME_PREF);
        if (authPrefs == null) {
            authPrefs = getAuthPreferences();
        }
        
        if (this.log.isDebugEnabled()) {
            this.log.debug("Authentication schemes in the order of preference: " 
                + authPrefs);
        }

        AuthScheme authScheme = null;
        for (int i = 0; i < authPrefs.size(); i++) {
            String id = (String) authPrefs.get(i);
            Header challenge = challenges.get(id.toLowerCase(Locale.ENGLISH)); 

            if (challenge != null) {
                if (this.log.isDebugEnabled()) {
                    this.log.debug(id + " authentication scheme selected");
                }
                try {
                    authScheme = registry.getAuthScheme(id, response.getParams());
                    break;
                } catch (IllegalStateException e) {
                    if (this.log.isWarnEnabled()) {
                        this.log.warn("Authentication scheme " + id + " not supported");
                        // Try again
                    }
                }
            } else {
                if (this.log.isDebugEnabled()) {
                    this.log.debug("Challenge for " + id + " authentication scheme not available");
                    // Try again
                }
            }
        }
        if (authScheme == null) {
            // If none selected, something is wrong
            throw new AuthenticationException(
                "Unable to respond to any of these challenges: "
                    + challenges);
        }
        return authScheme;