Java tutorial
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See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.HC4.impl.client; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Queue; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HC4.FormattedHeader; import org.apache.http.HC4.Header; import org.apache.http.HC4.HttpHost; import org.apache.http.HC4.HttpResponse; import org.apache.http.HC4.annotation.Immutable; import org.apache.http.HC4.auth.AuthOption; import org.apache.http.HC4.auth.AuthSchemeProvider; import org.apache.http.HC4.client.AuthCache; import org.apache.http.HC4.client.AuthenticationStrategy; import org.apache.http.HC4.client.config.AuthSchemes; import org.apache.http.HC4.client.config.RequestConfig; import org.apache.http.HC4.client.protocol.HttpClientContext; import org.apache.http.HC4.config.Lookup; import org.apache.http.HC4.util.Args; import org.apache.http.HC4.auth.AuthScheme; import org.apache.http.HC4.auth.AuthScope; import org.apache.http.HC4.auth.Credentials; import org.apache.http.HC4.auth.MalformedChallengeException; import org.apache.http.HC4.client.CredentialsProvider; import org.apache.http.HC4.protocol.HTTP; import org.apache.http.HC4.protocol.HttpContext; import org.apache.http.HC4.util.CharArrayBuffer; @Immutable abstract class AuthenticationStrategyImpl implements AuthenticationStrategy { private final Log log = LogFactory.getLog(getClass()); private static final List<String> DEFAULT_SCHEME_PRIORITY = Collections.unmodifiableList(Arrays.asList( AuthSchemes.SPNEGO, AuthSchemes.KERBEROS, AuthSchemes.NTLM, AuthSchemes.DIGEST, AuthSchemes.BASIC)); private final int challengeCode; private final String headerName; /** * @param challengeCode for example SC_PROXY_AUTHENTICATION_REQUIRED or SC_UNAUTHORIZED * @param headerName for example "Proxy-Authenticate" or "WWW-Authenticate" */ AuthenticationStrategyImpl(final int challengeCode, final String headerName) { super(); this.challengeCode = challengeCode; this.headerName = headerName; } @Override public boolean isAuthenticationRequested(final HttpHost authhost, final HttpResponse response, final HttpContext context) { Args.notNull(response, "HTTP response"); final int status = response.getStatusLine().getStatusCode(); return status == this.challengeCode; } /** * Generates a map of challenge auth-scheme => Header entries. * * @return map: key=lower-cased auth-scheme name, value=Header that contains the challenge */ @Override public Map<String, Header> getChallenges(final HttpHost authhost, final HttpResponse response, final HttpContext context) throws MalformedChallengeException { Args.notNull(response, "HTTP response"); final Header[] headers = response.getHeaders(this.headerName); final Map<String, Header> map = new HashMap<String, Header>(headers.length); for (final Header header : headers) { final CharArrayBuffer buffer; int pos; if (header instanceof FormattedHeader) { buffer = ((FormattedHeader) header).getBuffer(); pos = ((FormattedHeader) header).getValuePos(); } else { final 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++; } final int beginIndex = pos; while (pos < buffer.length() && !HTTP.isWhitespace(buffer.charAt(pos))) { pos++; } final int endIndex = pos; final String s = buffer.substring(beginIndex, endIndex); map.put(s.toLowerCase(Locale.ROOT), header); } return map; } abstract Collection<String> getPreferredAuthSchemes(RequestConfig config); @Override public Queue<AuthOption> select(final Map<String, Header> challenges, final HttpHost authhost, final HttpResponse response, final HttpContext context) throws MalformedChallengeException { Args.notNull(challenges, "Map of auth challenges"); Args.notNull(authhost, "Host"); Args.notNull(response, "HTTP response"); Args.notNull(context, "HTTP context"); final HttpClientContext clientContext = HttpClientContext.adapt(context); final Queue<AuthOption> options = new LinkedList<AuthOption>(); final Lookup<AuthSchemeProvider> registry = clientContext.getAuthSchemeRegistry(); if (registry == null) { this.log.debug("Auth scheme registry not set in the context"); return options; } final CredentialsProvider credsProvider = clientContext.getCredentialsProvider(); if (credsProvider == null) { this.log.debug("Credentials provider not set in the context"); return options; } final RequestConfig config = clientContext.getRequestConfig(); Collection<String> authPrefs = getPreferredAuthSchemes(config); if (authPrefs == null) { authPrefs = DEFAULT_SCHEME_PRIORITY; } if (this.log.isDebugEnabled()) { this.log.debug("Authentication schemes in the order of preference: " + authPrefs); } for (final String id : authPrefs) { final Header challenge = challenges.get(id.toLowerCase(Locale.ROOT)); if (challenge != null) { final AuthSchemeProvider authSchemeProvider = registry.lookup(id); if (authSchemeProvider == null) { if (this.log.isWarnEnabled()) { this.log.warn("Authentication scheme " + id + " not supported"); // Try again } continue; } final AuthScheme authScheme = authSchemeProvider.create(context); authScheme.processChallenge(challenge); final AuthScope authScope = new AuthScope(authhost.getHostName(), authhost.getPort(), authScheme.getRealm(), authScheme.getSchemeName()); final Credentials credentials = credsProvider.getCredentials(authScope); if (credentials != null) { options.add(new AuthOption(authScheme, credentials)); } } else { if (this.log.isDebugEnabled()) { this.log.debug("Challenge for " + id + " authentication scheme not available"); // Try again } } } return options; } @Override public void authSucceeded(final HttpHost authhost, final AuthScheme authScheme, final HttpContext context) { Args.notNull(authhost, "Host"); Args.notNull(authScheme, "Auth scheme"); Args.notNull(context, "HTTP context"); final HttpClientContext clientContext = HttpClientContext.adapt(context); if (isCachable(authScheme)) { AuthCache authCache = clientContext.getAuthCache(); if (authCache == null) { authCache = new BasicAuthCache(); clientContext.setAuthCache(authCache); } if (this.log.isDebugEnabled()) { this.log.debug("Caching '" + authScheme.getSchemeName() + "' auth scheme for " + authhost); } authCache.put(authhost, authScheme); } } protected boolean isCachable(final AuthScheme authScheme) { if (authScheme == null || !authScheme.isComplete()) { return false; } final String schemeName = authScheme.getSchemeName(); return schemeName.equalsIgnoreCase(AuthSchemes.BASIC) || schemeName.equalsIgnoreCase(AuthSchemes.DIGEST); } @Override public void authFailed(final HttpHost authhost, final AuthScheme authScheme, final HttpContext context) { Args.notNull(authhost, "Host"); Args.notNull(context, "HTTP context"); final HttpClientContext clientContext = HttpClientContext.adapt(context); final AuthCache authCache = clientContext.getAuthCache(); if (authCache != null) { if (this.log.isDebugEnabled()) { this.log.debug("Clearing cached auth scheme for " + authhost); } authCache.remove(authhost); } } }