allow customizing httpRequestRetryHandler (#362)

* allow customizing httpRequestRetryHandler

* HttpRetryTest

Author: rashtao

src/main/java/com/arangodb/ArangoDB.java

@@ -45,6 +45,7 @@
 import com.arangodb.velocypack.*;
 import com.arangodb.velocystream.Request;
 import com.arangodb.velocystream.Response;
+import org.apache.http.client.HttpRequestRetryHandler;
 
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
@@ -187,6 +188,23 @@ public Builder hostnameVerifier(final HostnameVerifier hostnameVerifier) {
             return this;
         }
 
+        /**
+         * Sets the {@link HttpRequestRetryHandler} to be used when using http protocol.
+         *
+         * @param httpRequestRetryHandler HttpRequestRetryHandler to be used
+         * @return {@link ArangoDB.Builder}
+         *
+         * <br /><br />
+         * NOTE:
+         * Some ArangoDB HTTP endpoints do not honor RFC-2616 HTTP 1.1 specification in respect to
+         * <a href="https://tools.ietf.org/html/rfc2616#section-9.1">9.1 Safe and Idempotent Methods</a>.
+         * Please refer to <a href="https://www.arangodb.com/docs/stable/http/">HTTP API Documentation</a> for details.
+         */
+        public Builder httpRequestRetryHandler(final HttpRequestRetryHandler httpRequestRetryHandler) {
+            setHttpRequestRetryHandler(httpRequestRetryHandler);
+            return this;
+        }
+
         /**
          * Sets the chunk size when {@link Protocol#VST} is used.
          *
@@ -584,7 +602,7 @@ public synchronized ArangoDB build() {
             final ConnectionFactory connectionFactory = (protocol == null || Protocol.VST == protocol)
                     ? new VstConnectionFactorySync(host, timeout, connectionTtl, useSsl, sslContext)
                     : new HttpConnectionFactory(timeout, user, password, useSsl, sslContext, hostnameVerifier, custom,
-                    protocol, connectionTtl, httpCookieSpec);
+                    protocol, connectionTtl, httpCookieSpec, httpRequestRetryHandler);
 
             final Collection<Host> hostList = createHostList(max, connectionFactory);
             final HostResolver hostResolver = createHostResolver(hostList, max, connectionFactory);

src/main/java/com/arangodb/internal/InternalArangoDBBuilder.java

@@ -31,6 +31,7 @@
 import com.arangodb.util.ArangoSerializer;
 import com.arangodb.velocypack.VPack;
 import com.arangodb.velocypack.VPackParser;
+import org.apache.http.client.HttpRequestRetryHandler;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -74,6 +75,7 @@ public abstract class InternalArangoDBBuilder {
     protected String password;
     protected Boolean useSsl;
     protected String httpCookieSpec;
+    protected HttpRequestRetryHandler httpRequestRetryHandler;
     protected SSLContext sslContext;
     protected HostnameVerifier hostnameVerifier;
     protected Integer chunksize;
@@ -166,6 +168,10 @@ protected void setHostnameVerifier(final HostnameVerifier hostnameVerifier) {
         this.hostnameVerifier = hostnameVerifier;
     }
 
+    protected void setHttpRequestRetryHandler(final HttpRequestRetryHandler httpRequestRetryHandler) {
+        this.httpRequestRetryHandler = httpRequestRetryHandler;
+    }
+
     protected void setChunksize(final Integer chunksize) {
         this.chunksize = chunksize;
     }

src/main/java/com/arangodb/internal/http/HttpConnection.java

@@ -35,6 +35,7 @@
 import org.apache.http.auth.AuthenticationException;
 import org.apache.http.auth.Credentials;
 import org.apache.http.auth.UsernamePasswordCredentials;
+import org.apache.http.client.HttpRequestRetryHandler;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.*;
 import org.apache.http.client.utils.URLEncodedUtils;
@@ -90,6 +91,7 @@ public static class Builder {
         private SSLContext sslContext;
         private HostnameVerifier hostnameVerifier;
         private Integer timeout;
+        private HttpRequestRetryHandler httpRequestRetryHandler;
 
         public Builder user(final String user) {
             this.user = user;
@@ -146,8 +148,14 @@ public Builder timeout(final Integer timeout) {
             return this;
         }
 
+        public Builder httpRequestRetryHandler(final HttpRequestRetryHandler httpRequestRetryHandler) {
+            this.httpRequestRetryHandler = httpRequestRetryHandler;
+            return this;
+        }
+
         public HttpConnection build() {
-            return new HttpConnection(host, timeout, user, password, useSsl, sslContext, hostnameVerifier, util, contentType, ttl, httpCookieSpec);
+            return new HttpConnection(host, timeout, user, password, useSsl, sslContext, hostnameVerifier, util,
+                    contentType, ttl, httpCookieSpec, httpRequestRetryHandler);
         }
     }
 
@@ -162,7 +170,7 @@ public HttpConnection build() {
 
     private HttpConnection(final HostDescription host, final Integer timeout, final String user, final String password,
                            final Boolean useSsl, final SSLContext sslContext, final HostnameVerifier hostnameVerifier, final ArangoSerialization util, final Protocol contentType,
-                           final Long ttl, final String httpCookieSpec) {
+                           final Long ttl, final String httpCookieSpec, final HttpRequestRetryHandler httpRequestRetryHandler) {
         super();
         this.host = host;
         this.user = user;
@@ -197,7 +205,7 @@ private HttpConnection(final HostDescription host, final Integer timeout, final
         final ConnectionKeepAliveStrategy keepAliveStrategy = (response, context) -> HttpConnection.this.getKeepAliveDuration(response);
         final HttpClientBuilder builder = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig.build())
                 .setConnectionManager(cm).setKeepAliveStrategy(keepAliveStrategy)
-                .setRetryHandler(new DefaultHttpRequestRetryHandler());
+                .setRetryHandler(httpRequestRetryHandler != null ? httpRequestRetryHandler : new DefaultHttpRequestRetryHandler());
         if (ttl != null) {
             builder.setConnectionTimeToLive(ttl, TimeUnit.MILLISECONDS);
         }

src/main/java/com/arangodb/internal/http/HttpConnectionFactory.java

@@ -25,6 +25,7 @@
 import com.arangodb.internal.net.ConnectionFactory;
 import com.arangodb.internal.net.HostDescription;
 import com.arangodb.util.ArangoSerialization;
+import org.apache.http.client.HttpRequestRetryHandler;
 
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
@@ -37,12 +38,13 @@ public class HttpConnectionFactory implements ConnectionFactory {
     private final HttpConnection.Builder builder;
 
     public HttpConnectionFactory(final Integer timeout, final String user, final String password, final Boolean useSsl,
-                                 final SSLContext sslContext, final HostnameVerifier hostnameVerifier, final ArangoSerialization util, final Protocol protocol,
-                                 final Long connectionTtl, String httpCookieSpec) {
+                                 final SSLContext sslContext, final HostnameVerifier hostnameVerifier,
+                                 final ArangoSerialization util, final Protocol protocol, final Long connectionTtl,
+                                 final String httpCookieSpec, final HttpRequestRetryHandler httpRequestRetryHandler) {
         super();
         builder = new HttpConnection.Builder().timeout(timeout).user(user).password(password).useSsl(useSsl)
                 .sslContext(sslContext).hostnameVerifier(hostnameVerifier).serializationUtil(util).contentType(protocol)
-                .ttl(connectionTtl).httpCookieSpec(httpCookieSpec);
+                .ttl(connectionTtl).httpCookieSpec(httpCookieSpec).httpRequestRetryHandler(httpRequestRetryHandler);
 
     }
 

src/test/java/com/arangodb/internal/http/HttpRetryTest.java

@@ -0,0 +1,77 @@
+/*
+ * DISCLAIMER
+ *
+ * Copyright 2016 ArangoDB GmbH, Cologne, Germany
+ *
+ * Licensed 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.
+ *
+ * Copyright holder is ArangoDB GmbH, Cologne, Germany
+ */
+
+package com.arangodb.internal.http;
+
+
+import com.arangodb.ArangoDB;
+import com.arangodb.ArangoDBException;
+import com.arangodb.Protocol;
+import org.apache.http.client.HttpRequestRetryHandler;
+import org.apache.http.protocol.HttpContext;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.fail;
+
+/**
+ * @author Michele Rastelli
+ */
+public class HttpRetryTest {
+
+    private final static int RETRIES = 2;
+
+    private static class TestRetryHandler implements HttpRequestRetryHandler {
+        private int retriesCounter = 0;
+
+        @Override
+        public boolean retryRequest(IOException exception, int executionCount, HttpContext context) {
+            return ++retriesCounter < RETRIES;
+        }
+
+    }
+
+    /**
+     * remove host from src/test/resources/arangodb.properties to run this test
+     */
+    @Test
+    @Ignore
+    public void retry() {
+        TestRetryHandler retryHandler = new TestRetryHandler();
+        ArangoDB arangoDB = new ArangoDB.Builder()
+                .host("wrongHost", 8529)
+                .useProtocol(Protocol.HTTP_JSON)
+                .httpRequestRetryHandler(retryHandler)
+                .build();
+
+        try {
+            arangoDB.getVersion();
+            fail("it should throw I/O exception");
+        } catch (ArangoDBException e) {
+            assertThat(retryHandler.retriesCounter, is(RETRIES));
+        }
+
+    }
+
+}