HTTPCLIENT-1044: HttpRequestRetryHandler implementation compliant with the definition of idempotent methods given in the RFC 2616

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1068579 13f79535-47bb-0310-9956-ffa450edef68

httpclient/src/main/java/org/apache/http/impl/client/DefaultHttpRequestRetryHandler.java

@@ -109,8 +109,7 @@ public class DefaultHttpRequestRetryHandler implements HttpRequestRetryHandler {
 
         HttpRequest request = (HttpRequest)
             context.getAttribute(ExecutionContext.HTTP_REQUEST);
-        boolean idempotent = !(request instanceof HttpEntityEnclosingRequest);
-        if (idempotent) {
+        if (handleAsIdempotent(request)) {
             // Retry if the request is considered idempotent
             return true;
         }
@@ -142,4 +141,12 @@ public class DefaultHttpRequestRetryHandler implements HttpRequestRetryHandler {
     public int getRetryCount() {
         return retryCount;
     }
+
+    /**
+     * @since 4.2
+     */
+    protected boolean handleAsIdempotent(final HttpRequest request) {
+        return !(request instanceof HttpEntityEnclosingRequest);
+    }
+
 }

httpclient/src/main/java/org/apache/http/impl/client/StandardHttpRequestRetryHandler.java

@@ -0,0 +1,81 @@
+/*
+ * ====================================================================
+ * 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.util.Locale;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.http.HttpRequest;
+import org.apache.http.annotation.Immutable;
+import org.apache.http.client.HttpRequestRetryHandler;
+
+/**
+ * A {@link HttpRequestRetryHandler} which assumes that all requested
+ * HTTP methods which should be idempotent according to RFC-2616 are
+ * in fact idempotent and can be retried.
+ *
+ * According to RFC-2616 section 9.1.2 the idempotent HTTP methods are:
+ * GET, HEAD, PUT, DELETE, OPTIONS, and TRACE
+ *
+ * @since 4.2
+ */
+@Immutable
+public class StandardHttpRequestRetryHandler extends DefaultHttpRequestRetryHandler {
+
+    private final Map<String, Boolean> idempotentMethods;
+
+    /**
+     * Default constructor
+     */
+    public StandardHttpRequestRetryHandler(int retryCount, boolean requestSentRetryEnabled) {
+        super(retryCount, requestSentRetryEnabled);
+        this.idempotentMethods = new ConcurrentHashMap<String, Boolean>();
+        this.idempotentMethods.put("GET", Boolean.TRUE);
+        this.idempotentMethods.put("HEAD", Boolean.TRUE);
+        this.idempotentMethods.put("PUT", Boolean.TRUE);
+        this.idempotentMethods.put("DELETE", Boolean.TRUE);
+        this.idempotentMethods.put("OPTIONS", Boolean.TRUE);
+        this.idempotentMethods.put("TRACE", Boolean.TRUE);
+    }
+
+    /**
+     * Default constructor
+     */
+    public StandardHttpRequestRetryHandler() {
+        this(3, false);
+    }
+
+    @Override
+    protected boolean handleAsIdempotent(final HttpRequest request) {
+        String method = request.getRequestLine().getMethod().toUpperCase(Locale.US);
+        Boolean b = this.idempotentMethods.get(method);
+        return b != null && b.booleanValue();
+    }
+
+}