Initial port of the redirect handling code

git-svn-id: https://svn.apache.org/repos/asf/jakarta/httpcomponents/httpclient/trunk@537378 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/http/client/RedirectHandler.java

@@ -0,0 +1,78 @@
+/*
+ * $HeadURL$
+ * $Revision$
+ * $Date$
+ *
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  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.client;
+
+import java.net.URI;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.ProtocolException;
+import org.apache.http.protocol.HttpContext;
+
+/**
+ * A handler for determining if an HTTP request should be redirected to 
+ * a new location in response to an HTTP response received from the target
+ * server.
+ * 
+ * <p>
+ * Classes implementing this interface must synchronize access to shared
+ * data as methods of this interfrace may be executed from multiple threads 
+ * </p>
+ * 
+ * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
+ */
+public interface RedirectHandler {
+
+    /**
+     * Determines if a request should be redirected to a new location
+     * given the response from the target server.
+     * 
+     * @param response the response received from the target server
+     * 
+     * @return <code>true</code> if the request should be redirected, <code>false</code>
+     * otherwise
+     */
+    boolean isRedirectNeeded(HttpResponse response);
+    
+    /**
+     * Determines the location request is expected to be redirected to 
+     * given the response from the target server and the current request
+     * execution context.
+     * 
+     * @param response the response received from the target server
+     * @param context the context for the request execution
+     * 
+     * @return redirect URI 
+     */
+    URI getLocationURI(HttpResponse response, HttpContext context)
+            throws ProtocolException;
+
+}

src/java/org/apache/http/client/params/HttpClientParams.java

@@ -69,6 +69,14 @@ public class HttpClientParams {
      */
     public static final String PREEMPTIVE_AUTHENTICATION = "http.authentication.preemptive";
 
+    /** 
+     * Defines whether redirects should be handled automatically
+     * <p>
+     * This parameter expects a value of type {@link Boolean}.
+     * </p>
+     */
+    public static final String HANDLE_REDIRECTS = "http.protocol.handle-redirects";
+
     /**
      * Defines whether relative redirects should be rejected.
      * <p>
@@ -104,6 +112,15 @@ public class HttpClientParams {
      */
     public static final String COOKIE_POLICY = "http.protocol.cookie-policy";
     
+    /**
+     * Defines the request headers to be sent per default with each request.
+     * <p>
+     * This parameter expects a value of type {@link java.util.Collection}. The 
+     * collection is expected to contain {@link org.apache.http.Header}s. 
+     * </p>
+     */
+    public static final String DEFAULT_HEADERS = "http.default-headers"; 
+    
     private HttpClientParams() {
         super();
     }

src/java/org/apache/http/conn/HttpRoute.java

@@ -126,6 +126,17 @@ public final class HttpRoute {
     }
 
 
+    /**
+     * Creates a new direct insecure route.
+     * That is a route without a proxy.
+     *
+     * @param target    the host to which to route
+     */
+    public HttpRoute(HttpHost target) {
+        this(target, null, null, false, false, false);
+    }
+
+
     /**
      * Creates a new route through a proxy.
      * When using this constructor, the <code>proxy</code> MUST be given.

src/java/org/apache/http/impl/client/AbstractHttpClient.java

@@ -47,6 +47,7 @@ import org.apache.http.client.ClientRequestDirector;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.HttpRequestRetryHandler;
 import org.apache.http.client.HttpState;
+import org.apache.http.client.RedirectHandler;
 import org.apache.http.client.RoutedRequest;
 import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.conn.ClientConnectionManager;
@@ -99,6 +100,9 @@ public abstract class AbstractHttpClient
     /** The request retry handler. */
     private HttpRequestRetryHandler retryHandler;
 
+    /** The redirect handler. */
+    private RedirectHandler redirectHandler;
+
     /** The default HTTP state. */
     private HttpState defaultState;
 
@@ -140,6 +144,9 @@ public abstract class AbstractHttpClient
     protected abstract HttpRequestRetryHandler createHttpRequestRetryHandler();
 
     
+    protected abstract RedirectHandler createRedirectHandler();
+
+    
     protected abstract HttpState createHttpState();
     
     
@@ -231,6 +238,19 @@ public abstract class AbstractHttpClient
     }
 
 
+    public synchronized final RedirectHandler getRedirectHandler() {
+        if (redirectHandler == null) {
+            redirectHandler = createRedirectHandler();
+        }
+        return redirectHandler;
+    }
+
+
+    public synchronized void setRedirectHandler(final RedirectHandler redirectHandler) {
+        this.redirectHandler = redirectHandler;
+    }
+
+
     public synchronized final HttpState getState() {
         if (defaultState == null) {
             defaultState = createHttpState();
@@ -397,6 +417,7 @@ public abstract class AbstractHttpClient
                     getConnectionReuseStrategy(),
                     getHttpProcessor().copy(),
                     getHttpRequestRetryHandler(),
+                    getRedirectHandler(),
                     getParams());
         }
 

src/java/org/apache/http/impl/client/DefaultClientRequestDirector.java

@@ -32,12 +32,16 @@
 package org.apache.http.impl.client;
 
 import java.io.IOException;
+import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.Collection;
+import java.util.Iterator;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.http.ConnectionReuseStrategy;
+import org.apache.http.Header;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpEntityEnclosingRequest;
 import org.apache.http.HttpException;
@@ -48,8 +52,10 @@ import org.apache.http.HttpVersion;
 import org.apache.http.ProtocolException;
 import org.apache.http.client.ClientRequestDirector;
 import org.apache.http.client.HttpRequestRetryHandler;
+import org.apache.http.client.RedirectHandler;
 import org.apache.http.client.RoutedRequest;
 import org.apache.http.client.methods.AbortableHttpRequest;
+import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.params.HttpClientParams;
 import org.apache.http.conn.BasicManagedEntity;
 import org.apache.http.conn.ClientConnectionManager;
@@ -57,6 +63,8 @@ import org.apache.http.conn.ConnectionPoolTimeoutException;
 import org.apache.http.conn.HttpRoute;
 import org.apache.http.conn.ManagedClientConnection;
 import org.apache.http.conn.RouteDirector;
+import org.apache.http.conn.Scheme;
+import org.apache.http.conn.SchemeRegistry;
 import org.apache.http.message.BasicHttpRequest;
 import org.apache.http.params.HttpConnectionParams;
 import org.apache.http.params.HttpParams;
@@ -98,6 +106,9 @@ public class DefaultClientRequestDirector
     /** The request retry handler. */
     protected final HttpRequestRetryHandler retryHandler;
     
+    /** The redirect handler. */
+    protected final RedirectHandler redirectHandler;
+    
     /** The HTTP parameters. */
     protected final HttpParams params;
     
@@ -110,6 +121,7 @@ public class DefaultClientRequestDirector
             final ConnectionReuseStrategy reustrat,
             final HttpProcessor httpProcessor,
             final HttpRequestRetryHandler retryHandler,
+            final RedirectHandler redirectHandler,
             final HttpParams params) {
 
         if (conman == null) {
@@ -124,6 +136,9 @@ public class DefaultClientRequestDirector
         if (retryHandler == null) {
             throw new IllegalArgumentException("HTTP request retry handler may not be null");
         }
+        if (redirectHandler == null) {
+            throw new IllegalArgumentException("Redirect handler may not be null");
+        }
         if (params == null) {
             throw new IllegalArgumentException("HTTP parameters may not be null");
         }
@@ -131,6 +146,7 @@ public class DefaultClientRequestDirector
         this.reuseStrategy = reustrat;
         this.httpProcessor = httpProcessor;
         this.retryHandler  = retryHandler;
+        this.redirectHandler = redirectHandler;
         this.params        = params;
         this.requestExec   = new HttpRequestExecutor(params);
 
@@ -206,20 +222,35 @@ public class DefaultClientRequestDirector
     public HttpResponse execute(RoutedRequest roureq, HttpContext context)
         throws HttpException, IOException {
 
-        RequestWrapper request = wrapRequest(roureq.getRequest());
+        HttpRequest orig = roureq.getRequest();
+        
+        // Link parameter collections to form a hierarchy:
+        // request -> client
+        orig.getParams().setDefaults(this.params);
+
+        // Add default headers
+        Collection defHeaders = (Collection) orig.getParams().getParameter(
+                HttpClientParams.DEFAULT_HEADERS);
+        if (defHeaders != null) {
+            for (Iterator it = defHeaders.iterator(); it.hasNext(); ) {
+                orig.addHeader((Header) it.next());
+            }
+        }
+        
+        int execCount = 0;
+
         HttpResponse response = null;
         boolean done = false;
-
         try {
-            int execCount = 0;
             while (!done) {
 
+                RequestWrapper request = wrapRequest(roureq.getRequest());
                 HttpRoute route = roureq.getRoute();
 
                 // Re-write request URI if needed
                 rewriteRequestURI(request, route);
                 
-                if (managedConn == null) {
+                if (managedConn == null || !managedConn.isOpen()) {
                     managedConn = allocateConnection(route);
                 }
                 establishRoute(route, context);
@@ -465,9 +496,9 @@ public class DefaultClientRequestDirector
      * Analyzes a response to check need for a followup.
      *
      * @param roureq    the request and route. This is the same object as
-     *                  was passed to {@link #prepareRequest prepareRequest}.
+     *                  was passed to {@link #wrapRequest(HttpRequest)}.
      * @param request   the request that was actually sent. This is the object
-     *                  returned by {@link #prepareRequest prepareRequest}.
+     *                  returned by {@link #wrapRequest(HttpRequest)}.
      * @param response  the response to analayze
      * @param context   the context used for the current request execution
      *
@@ -483,15 +514,50 @@ public class DefaultClientRequestDirector
                                            HttpContext context)
         throws HttpException, IOException {
 
-        //@@@ if there is a followup, check connection keep-alive and
+        HttpParams params = request.getParams();
-        //@@@ consume response body if necessary or close otherwise
+        if (params.getBooleanParameter(HttpClientParams.HANDLE_REDIRECTS, true) && 
+                this.redirectHandler.isRedirectNeeded(response)) {
 
-        //@@@ if the request needs to be re-sent with authentication,
+            URI uri;
-        //@@@ how to revert the modifications applied by the interceptors?
+            try {
-        //@@@ use a wrapper when sending?
+                uri = this.redirectHandler.getLocationURI(response, context);
+            } catch (ProtocolException ex) {
+                if (LOG.isWarnEnabled()) {
+                    LOG.warn(ex.getMessage());
+                }
+                return null;
+            }
 
+            HttpRoute oldRoute = roureq.getRoute();
+
+            HttpHost newTarget = new HttpHost(
+                    uri.getHost(), 
+                    uri.getPort(),
+                    uri.getScheme());
+            
+            SchemeRegistry schemeRegistry = this.connManager.getSchemeRegistry();
+            Scheme schm = schemeRegistry.getScheme(newTarget.getSchemeName());
+            
+            InetAddress localAddress = oldRoute.getLocalAddress();
+            HttpHost proxy = oldRoute.getProxyHost();
+            
+            HttpRoute newRoute = new HttpRoute(
+                    newTarget,
+                    localAddress,
+                    proxy,
+                    schm.isLayered(),
+                    (proxy != null),
+                    (proxy != null));
+
+            HttpGet redirect = new HttpGet(uri);
+            
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Redirecting to '" + uri + "' via " + newRoute);
+            }
+            
+            return new RoutedRequest.Impl(redirect, newRoute);
+        }
         return null;
-
     } // handleResponse
 
 

src/java/org/apache/http/impl/client/DefaultHttpClient.java

@@ -39,6 +39,7 @@ import org.apache.http.HttpVersion;
 import org.apache.http.auth.AuthSchemeRegistry;
 import org.apache.http.client.HttpRequestRetryHandler;
 import org.apache.http.client.HttpState;
+import org.apache.http.client.RedirectHandler;
 import org.apache.http.client.RoutedRequest;
 import org.apache.http.client.params.AuthPolicy;
 import org.apache.http.client.params.CookiePolicy;
@@ -211,6 +212,11 @@ public class DefaultHttpClient extends AbstractHttpClient {
     }
 
 
+    protected RedirectHandler createRedirectHandler() {
+        return new DefaultRedirectHandler();
+    }
+
+
     protected HttpState createHttpState() {
         return new HttpState();
     }

src/java/org/apache/http/impl/client/DefaultRedirectHandler.java

@@ -0,0 +1,137 @@
+/*
+ * $HeadURL$
+ * $Revision$
+ * $Date$
+ *
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  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.impl.client;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.http.Header;
+import org.apache.http.HttpHost;
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.apache.http.ProtocolException;
+import org.apache.http.client.RedirectHandler;
+import org.apache.http.client.params.HttpClientParams;
+import org.apache.http.params.HttpParams;
+import org.apache.http.protocol.HttpContext;
+import org.apache.http.protocol.HttpExecutionContext;
+
+/**
+ * Default implementation of a redirect handler.
+ * 
+ * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
+ *
+ * <!-- empty lines to avoid svn diff problems -->
+ * @version $Revision$
+ *
+ * @since 4.0
+ */
+public class DefaultRedirectHandler implements RedirectHandler {
+
+    private static final Log LOG = LogFactory.getLog(DefaultRedirectHandler.class);
+
+    public boolean isRedirectNeeded(final HttpResponse response) {
+        if (response == null) {
+            throw new IllegalArgumentException("HTTP response may not be null");
+        }
+        int statusCode = response.getStatusLine().getStatusCode();
+        switch (statusCode) {
+        case HttpStatus.SC_MOVED_TEMPORARILY:
+        case HttpStatus.SC_MOVED_PERMANENTLY:
+        case HttpStatus.SC_SEE_OTHER:
+        case HttpStatus.SC_TEMPORARY_REDIRECT:
+            return true;
+        default:
+            return false;
+        } //end of switch
+    }
+ 
+    public URI getLocationURI(
+            final HttpResponse response, 
+            final HttpContext context) throws ProtocolException {
+        if (response == null) {
+            throw new IllegalArgumentException("HTTP response may not be null");
+        }
+        //get the location header to find out where to redirect to
+        Header locationHeader = response.getFirstHeader("location");
+        if (locationHeader == null) {
+            // got a redirect response, but no location header
+            throw new ProtocolException(
+                    "Received redirect response " + response.getStatusLine()
+                    + " but no location header");
+        }
+        String location = locationHeader.getValue();
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("Redirect requested to location '" + location + "'");
+        }
+
+        URI uri;
+        try {
+            uri = new URI(location);            
+        } catch (URISyntaxException ex) {
+            throw new ProtocolException("Invalid redirect URI: " + location, ex);
+        }
+
+        HttpParams params = response.getParams();
+        // rfc2616 demands the location value be a complete URI
+        // Location       = "Location" ":" absoluteURI
+        if (!uri.isAbsolute()) {
+            if (params.isParameterTrue(HttpClientParams.REJECT_RELATIVE_REDIRECT)) {
+                throw new ProtocolException("Relative redirect location '" 
+                        + uri + "' not allowed");
+            }
+            // Adjust location URI
+            HttpHost target = (HttpHost) context.getAttribute(
+                    HttpExecutionContext.HTTP_TARGET_HOST);
+            if (target == null) {
+                throw new IllegalStateException("Target host not available " +
+                        "in the HTTP context");
+            }
+            try {
+                uri = new URI(
+                        target.getSchemeName(),
+                        null,
+                        target.getHostName(),
+                        target.getPort(),
+                        uri.getPath(),
+                        uri.getQuery(),
+                        uri.getFragment());
+            } catch (URISyntaxException ex) {
+                throw new ProtocolException(ex.getMessage(), ex);
+            }
+        }
+        return uri;
+    }
+
+}

src/java/org/apache/http/impl/client/RequestWrapper.java

@@ -130,8 +130,8 @@ class RequestWrapper extends AbstractHttpMessage implements HttpUriRequest {
         return new BasicRequestLine(method, uritext, ver);
     }
 
-    public void resetHeaders() {
+    public HttpRequest getOriginal() {
-        setHeaders(this.original.getAllHeaders());
+        return this.original;
     }
     
 }