Add a method to get all values of HTTP header defined as list

According to RFC 2616 [1] header field names are case insensitive.
Header fields defined as a comma separated list can have multiple header
fields with the same field name. Add a method to HttpConnection which
retrieves all values with a given header field name with the field name
compared case insensitive.

[1] https://tools.ietf.org/html/rfc2616#section-4.2"

Change-Id: I7f601b21cda99e84f43f866c7c7cb4cb0e3cf5c3
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.http.apache/META-INF/MANIFEST.MF

@@ -23,6 +23,7 @@ Import-Package: org.apache.http;version="[4.3.0,5.0.0)",
  org.apache.http.impl.client;version="[4.3.0,5.0.0)",
  org.apache.http.impl.conn;version="[4.3.0,5.0.0)",
  org.apache.http.params;version="[4.3.0,5.0.0)",
+ org.eclipse.jgit.annotations;version="[5.2.0,5.3.0)",
  org.eclipse.jgit.nls;version="[5.2.0,5.3.0)",
  org.eclipse.jgit.transport.http;version="[5.2.0,5.3.0)",
  org.eclipse.jgit.util;version="[5.2.0,5.3.0)"

org.eclipse.jgit.http.apache/src/org/eclipse/jgit/transport/http/apache/HttpClientConnection.java

@@ -58,10 +58,13 @@ import java.net.URL;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.KeyManager;
@@ -90,6 +93,7 @@ import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
+import org.eclipse.jgit.annotations.NonNull;
 import org.eclipse.jgit.transport.http.HttpConnection;
 import org.eclipse.jgit.transport.http.apache.internal.HttpApacheText;
 import org.eclipse.jgit.util.TemporaryBuffer;
@@ -347,11 +351,17 @@ public class HttpClientConnection implements HttpConnection {
 	// will return only the first field
 	/** {@inheritDoc} */
 	@Override
-	public String getHeaderField(String name) {
+	public String getHeaderField(@NonNull String name) {
 		Header header = resp.getFirstHeader(name);
 		return (header == null) ? null : header.getValue();
 	}
 
+	@Override
+	public List<String> getHeaderFields(@NonNull String name) {
+		return Collections.unmodifiableList(Arrays.asList(resp.getHeaders(name))
+				.stream().map(Header::getValue).collect(Collectors.toList()));
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public int getContentLength() {

org.eclipse.jgit.test/META-INF/MANIFEST.MF

@@ -10,6 +10,7 @@ Bundle-ActivationPolicy: lazy
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Import-Package: com.googlecode.javaewah;version="[1.1.6,2.0.0)",
  com.jcraft.jsch;version="[0.1.54,0.2.0)",
+ net.bytebuddy.dynamic.loading;version="[1.7.0,2.0.0)",
  org.eclipse.jgit.annotations;version="[5.2.0,5.3.0)",
  org.eclipse.jgit.api;version="[5.2.0,5.3.0)",
  org.eclipse.jgit.api.errors;version="[5.2.0,5.3.0)",
@@ -63,6 +64,11 @@ Import-Package: com.googlecode.javaewah;version="[1.1.6,2.0.0)",
  org.junit.rules;version="[4.12,5.0.0)",
  org.junit.runner;version="[4.12,5.0.0)",
  org.junit.runners;version="[4.12,5.0.0)",
+ org.mockito;version="[2.13.0,3.0.0)",
+ org.mockito.invocation;version="[2.13.0,3.0.0)",
+ org.mockito.junit;version="[2.13.0,3.0.0)",
+ org.mockito.stubbing;version="[2.13.0,3.0.0)",
+ org.objenesis;version="[2.6.0,3.0.0)",
  org.slf4j;version="[1.7.0,2.0.0)"
 Require-Bundle: org.hamcrest.core;bundle-version="[1.1.0,2.0.0)",
  org.hamcrest.library;bundle-version="[1.1.0,2.0.0)"

org.eclipse.jgit.test/pom.xml

@@ -89,6 +89,12 @@
       <version>[1.1.0,2.0.0)</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <version>2.13.0</version>
+    </dependency>
+
     <dependency>
       <groupId>org.eclipse.jgit</groupId>
       <artifactId>org.eclipse.jgit</artifactId>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/http/JDKHttpConnectionTest.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2018 Matthias Sohn <matthias.sohn@sap.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.transport.http;
+
+import static java.util.Arrays.asList;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.net.HttpURLConnection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class JDKHttpConnectionTest {
+
+	private Map<String, List<String>> headers = new HashMap<>();
+
+	private HttpURLConnection u;
+
+	private JDKHttpConnection c;
+
+	@Before
+	public void setup() {
+		u = mock(HttpURLConnection.class);
+		c = new JDKHttpConnection(u);
+		headers.put("ABC", asList("x"));
+	}
+
+	@Test
+	public void testSingle() {
+		when(u.getHeaderFields()).thenReturn(headers);
+		assertValues("AbC", "x");
+	}
+
+	@Test
+	public void testMultiple1() {
+		headers.put("abc", asList("a"));
+		headers.put("aBC", asList("d", "e"));
+		headers.put("ABc", Collections.emptyList());
+		headers.put("AbC", (List<String>) null);
+		when(u.getHeaderFields()).thenReturn(headers);
+		assertValues("AbC", "a", "d", "e", "x");
+	}
+
+	@Test
+	public void testMultiple2() {
+		headers.put("ab", asList("y", "z", "z"));
+		when(u.getHeaderFields()).thenReturn(headers);
+		assertValues("ab", "z", "y", "z");
+		assertValues("abc", "x");
+		assertValues("aBc", "x");
+		assertValues("AbCd");
+	}
+
+	@Test
+	public void testCommaSeparatedList() {
+		headers.put("abc", asList("a,b,c", "d"));
+		when(u.getHeaderFields()).thenReturn(headers);
+		assertValues("Abc", "a,b,c", "x", "d");
+	}
+
+	private void assertValues(String key, String... values) {
+		List<String> l = new LinkedList<>();
+		List<String> hf = c.getHeaderFields(key);
+		if (hf != null) {
+			l.addAll(hf);
+		}
+		for (String v : values) {
+			if (!l.remove(v)) {
+				fail("value " + v + " not found");
+			}
+		}
+		assertTrue("found unexpected entries " + l, l.isEmpty());
+	}
+
+}

org.eclipse.jgit/.settings/.api_filters

@@ -66,4 +66,12 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/transport/http/HttpConnection.java" type="org.eclipse.jgit.transport.http.HttpConnection">
+        <filter id="403804204">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.transport.http.HttpConnection"/>
+                <message_argument value="getHeaderFields(String)"/>
+            </message_arguments>
+        </filter>
+    </resource>
 </component>

org.eclipse.jgit/src/org/eclipse/jgit/transport/http/HttpConnection.java

@@ -58,6 +58,8 @@ import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.TrustManager;
 
+import org.eclipse.jgit.annotations.NonNull;
+
 /**
  * The interface of connections used during HTTP communication. This interface
  * is that subset of the interface exposed by {@link java.net.HttpURLConnection}
@@ -139,7 +141,7 @@ public interface HttpConnection {
 	String getResponseMessage() throws IOException;
 
 	/**
-	 * Get list of header fields
+	 * Get map of header fields
 	 *
 	 * @see HttpURLConnection#getHeaderFields()
 	 * @return a Map of header fields
@@ -225,7 +227,13 @@ public interface HttpConnection {
 	InputStream getInputStream() throws IOException;
 
 	/**
-	 * Get header field
+	 * Get header field. According to
+	 * {@link <a href="https://tools.ietf.org/html/rfc2616#section-4.2">RFC
+	 * 2616</a>} header field names are case insensitive. Header fields defined
+	 * as a comma separated list can have multiple header fields with the same
+	 * field name. This method only returns one of these header fields. If you
+	 * want the union of all values of all multiple header fields with the same
+	 * field name then use {@link #getHeaderFields(String)}
 	 *
 	 * @see HttpURLConnection#getHeaderField(String)
 	 * @param name
@@ -233,7 +241,22 @@ public interface HttpConnection {
 	 * @return the value of the named header field, or <code>null</code> if
 	 *         there is no such field in the header.
 	 */
-	String getHeaderField(String name);
+	String getHeaderField(@NonNull String name);
+
+	/**
+	 * Get all values of given header field. According to
+	 * {@link <a href="https://tools.ietf.org/html/rfc2616#section-4.2">RFC
+	 * 2616</a>} header field names are case insensitive. Header fields defined
+	 * as a comma separated list can have multiple header fields with the same
+	 * field name. This method does not validate if the given header field is
+	 * defined as a comma separated list.
+	 *
+	 * @param name
+	 *            the name of a header field.
+	 * @return the list of values of the named header field
+	 * @since 5.2
+	 */
+	List<String> getHeaderFields(@NonNull String name);
 
 	/**
 	 * Get content length

org.eclipse.jgit/src/org/eclipse/jgit/transport/http/JDKHttpConnection.java

@@ -53,6 +53,7 @@ import java.net.URL;
 import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
@@ -62,6 +63,7 @@ import javax.net.ssl.KeyManager;
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.TrustManager;
 
+import org.eclipse.jgit.annotations.NonNull;
 /**
  * A {@link org.eclipse.jgit.transport.http.HttpConnection} which simply
  * delegates every call to a {@link java.net.HttpURLConnection}. This is the
@@ -72,6 +74,11 @@ import javax.net.ssl.TrustManager;
 public class JDKHttpConnection implements HttpConnection {
 	HttpURLConnection wrappedUrlConnection;
 
+	// used for mock testing
+	JDKHttpConnection(HttpURLConnection urlConnection) {
+		this.wrappedUrlConnection = urlConnection;
+	}
+
 	/**
 	 * Constructor for JDKHttpConnection.
 	 *
@@ -170,10 +177,26 @@ public class JDKHttpConnection implements HttpConnection {
 
 	/** {@inheritDoc} */
 	@Override
-	public String getHeaderField(String name) {
+	public String getHeaderField(@NonNull String name) {
 		return wrappedUrlConnection.getHeaderField(name);
 	}
 
+	@Override
+	public List<String> getHeaderFields(@NonNull String name) {
+		Map<String, List<String>> m = wrappedUrlConnection.getHeaderFields();
+		List<String> fields = mapValuesToListIgnoreCase(name, m);
+		return fields;
+	}
+
+	private static List<String> mapValuesToListIgnoreCase(String keyName,
+			Map<String, List<String>> m) {
+		List<String> fields = new LinkedList<>();
+		m.entrySet().stream().filter(e -> keyName.equalsIgnoreCase(e.getKey()))
+				.filter(e -> e.getValue() != null)
+				.forEach(e -> fields.addAll(e.getValue()));
+		return fields;
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public int getContentLength() {