SLF4J logging facade

httpclient5-cache/pom.xml

@@ -45,14 +45,18 @@
       <scope>compile</scope>
     </dependency>
     <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
+      <groupId>org.slf4j</groupId>
-      <artifactId>log4j-api</artifactId>
+      <artifactId>slf4j-api</artifactId>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-core</artifactId>
-      <version>${log4j.version}</version>
       <scope>test</scope>
     </dependency>
     <dependency>

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/BasicHttpAsyncCache.java

@@ -50,12 +50,12 @@ import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.message.RequestLine;
 import org.apache.hc.core5.http.message.StatusLine;
 import org.apache.hc.core5.util.ByteArrayBuffer;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class BasicHttpAsyncCache implements HttpAsyncCache {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final CacheUpdateHandler cacheUpdateHandler;
     private final CacheKeyGenerator cacheKeyGenerator;

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/BasicHttpCache.java

@@ -46,12 +46,12 @@ import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.message.RequestLine;
 import org.apache.hc.core5.http.message.StatusLine;
 import org.apache.hc.core5.util.ByteArrayBuffer;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class BasicHttpCache implements HttpCache {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final CacheUpdateHandler cacheUpdateHandler;
     private final CacheKeyGenerator cacheKeyGenerator;

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheRevalidatorBase.java

@@ -45,8 +45,8 @@ import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Abstract cache re-validation class.
@@ -94,7 +94,7 @@ class CacheRevalidatorBase implements Closeable {
     private final Set<String> pendingRequest;
     private final ConcurrentCountMap<String> failureCache;
 
-    final Logger log = LogManager.getLogger(getClass());
+    final Logger log = LoggerFactory.getLogger(getClass());
 
     /**
      * Create CacheValidator which will make ache revalidation requests

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheableRequestPolicy.java

@@ -36,8 +36,8 @@ import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpVersion;
 import org.apache.hc.core5.http.ProtocolVersion;
 import org.apache.hc.core5.http.message.MessageSupport;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Determines if an HttpRequest is allowed to be served from the cache.
@@ -47,7 +47,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class CacheableRequestPolicy {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     /**
      * Determines if an HttpRequest can be served from the cache.

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachedResponseSuitabilityChecker.java

@@ -40,8 +40,8 @@ import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpStatus;
 import org.apache.hc.core5.http.message.MessageSupport;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Determines whether a given {@link HttpCacheEntry} is suitable to be
@@ -52,7 +52,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class CachedResponseSuitabilityChecker {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final boolean sharedCache;
     private final boolean useHeuristicCaching;

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java

@@ -69,8 +69,8 @@ import org.apache.hc.core5.http.protocol.HttpCoreContext;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.ByteArrayBuffer;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * <p>
@@ -107,7 +107,7 @@ public class CachingExec extends CachingExecBase implements ExecChainHandler {
     private final DefaultCacheRevalidator cacheRevalidator;
     private final ConditionalRequestBuilder<ClassicHttpRequest> conditionalRequestBuilder;
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     CachingExec(final HttpCache cache, final DefaultCacheRevalidator cacheRevalidator, final CacheConfig config) {
         super(config);

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExecBase.java

@@ -54,8 +54,8 @@ import org.apache.hc.core5.http.ProtocolVersion;
 import org.apache.hc.core5.http.message.MessageSupport;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.VersionInfo;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class CachingExecBase {
 
@@ -76,7 +76,7 @@ public class CachingExecBase {
     final RequestProtocolCompliance requestCompliance;
     final CacheConfig cacheConfig;
 
-    final Logger log = LogManager.getLogger(getClass());
+    final Logger log = LoggerFactory.getLogger(getClass());
 
     CachingExecBase(
             final CacheValidityPolicy validityPolicy,

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/DefaultAsyncCacheInvalidator.java

@@ -47,8 +47,8 @@ import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.HttpStatus;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Given a particular HTTP request / response pair, flush any cache entries
@@ -62,7 +62,7 @@ public class DefaultAsyncCacheInvalidator extends CacheInvalidatorBase implement
 
     public static final DefaultAsyncCacheInvalidator INSTANCE = new DefaultAsyncCacheInvalidator();
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private void removeEntry(final HttpAsyncCacheStorage storage, final String cacheKey) {
         storage.removeEntry(cacheKey, new FutureCallback<Boolean>() {

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/DefaultCacheInvalidator.java

@@ -41,8 +41,8 @@ import org.apache.hc.core5.http.Header;
 import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpResponse;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Given a particular HTTP request / response pair, flush any cache entries
@@ -56,7 +56,7 @@ public class DefaultCacheInvalidator extends CacheInvalidatorBase implements Htt
 
     public static final DefaultCacheInvalidator INSTANCE = new DefaultCacheInvalidator();
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private HttpCacheEntry getEntry(final HttpCacheStorage storage, final String cacheKey) {
         try {

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/ResponseCachingPolicy.java

@@ -46,8 +46,8 @@ import org.apache.hc.core5.http.HttpStatus;
 import org.apache.hc.core5.http.HttpVersion;
 import org.apache.hc.core5.http.ProtocolVersion;
 import org.apache.hc.core5.http.message.MessageSupport;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Determines if an HttpResponse can be cached.
@@ -68,7 +68,7 @@ class ResponseCachingPolicy {
                     HttpStatus.SC_MOVED_PERMANENTLY,
                     HttpStatus.SC_GONE));
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final long maxObjectSizeBytes;
     private final boolean sharedCache;

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/memcached/SHA256KeyHashingScheme.java

@@ -30,8 +30,8 @@ import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
 import org.apache.commons.codec.binary.Hex;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * This is a {@link KeyHashingScheme} based on the
@@ -44,7 +44,7 @@ public final class SHA256KeyHashingScheme implements KeyHashingScheme {
 
     public static final SHA256KeyHashingScheme INSTANCE = new SHA256KeyHashingScheme();
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     @Override
     public String hash(final String key) {

httpclient5-fluent/pom.xml

@@ -51,15 +51,19 @@
       <scope>test</scope>
       <classifier>tests</classifier>
     </dependency>
-    <!-- direct dependency on logging -->
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <scope>compile</scope>
+    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-api</artifactId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-core</artifactId>
-      <version>${log4j.version}</version>
       <scope>test</scope>
     </dependency>
     <dependency>

httpclient5-osgi/pom.xml

@@ -40,8 +40,8 @@
   <packaging>bundle</packaging>
 
   <properties>
-    <httpcore.osgi.import.version>"5.0-alpha2"</httpcore.osgi.import.version>
+    <httpcore.osgi.import.version>"5.0-beta1"</httpcore.osgi.import.version>
-    <log4j.osgi.import.version>"2.8"</log4j.osgi.import.version>
+    <slf4j.osgi.import.version>"[1.7, 1.8)"</slf4j.osgi.import.version>
     <osgi.framework.version>5.0.0</osgi.framework.version>
   </properties>
 
@@ -57,12 +57,6 @@
       <artifactId>httpcore5-osgi</artifactId>
       <version>${httpcore.version}</version>
       <scope>provided</scope>
-      <exclusions>
-        <exclusion>
-            <groupId>org.apache.httpcomponents.client5</groupId>
-            <artifactId>httpcore-nio</artifactId>
-        </exclusion>
-      </exclusions>
     </dependency>
     <dependency>
       <groupId>commons-codec</groupId>
@@ -134,7 +128,7 @@
                 org.ietf.jgss,,
                 org.osgi.framework,
                 org.osgi.service.cm,
-                org.apache.logging.log4j;version=${log4j.osgi.import.version},
+                org.slf4j;version=${slf4j.osgi.import.version},
                 org.apache.hc.core5.*;version=${httpcore.osgi.import.version},
                 org.ehcache.*;resolution:=optional,
                 net.spy.memcached.*;resolution:=optional

httpclient5-osgi/src/main/java/org/apache/hc/client5/http/osgi/impl/OSGiCredentialsProvider.java

@@ -35,15 +35,15 @@ import org.apache.hc.client5.http.auth.NTCredentials;
 import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
 import org.apache.hc.client5.http.osgi.services.ProxyConfiguration;
 import org.apache.hc.core5.http.protocol.HttpContext;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @since 4.3
  */
 final class OSGiCredentialsProvider implements CredentialsStore {
 
-    private static final Logger log = LogManager.getLogger(OSGiCredentialsProvider.class);
+    private static final Logger log = LoggerFactory.getLogger(OSGiCredentialsProvider.class);
 
     private static final int HOST_AND_PORT_MATCH = 12;
 

httpclient5-testing/pom.xml

@@ -48,6 +48,18 @@
       <version>${project.version}</version>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>compile</scope>
+      <optional>true</optional>
+    </dependency>
+    <!-- TODO remove after upgrade to HttpCore 5.0b2 -->
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-api</artifactId>
@@ -57,6 +69,7 @@
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-core</artifactId>
       <scope>compile</scope>
+      <optional>true</optional>
     </dependency>
     <dependency>
       <groupId>org.apache.httpcomponents.client5</groupId>

httpclient5-win/pom.xml

@@ -50,6 +50,21 @@
       <scope>test</scope>
       <classifier>tests</classifier>
     </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>net.java.dev.jna</groupId>
       <artifactId>jna</artifactId>
@@ -65,11 +80,6 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-core</artifactId>
-      <scope>test</scope>
-    </dependency>
   </dependencies>
 
   <reporting>

httpclient5-win/src/main/java/org/apache/hc/client5/http/impl/win/WindowsNegotiateScheme.java

@@ -44,8 +44,8 @@ import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.sun.jna.platform.win32.Secur32;
 import com.sun.jna.platform.win32.Secur32Util;
@@ -71,7 +71,7 @@ import com.sun.jna.ptr.IntByReference;
  */
 public class WindowsNegotiateScheme implements AuthScheme {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     // NTLM or Negotiate
     private final String scheme;

httpclient5/pom.xml

@@ -48,14 +48,18 @@
       <scope>compile</scope>
     </dependency>
     <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
+      <groupId>org.slf4j</groupId>
-      <artifactId>log4j-api</artifactId>
+      <artifactId>slf4j-api</artifactId>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-core</artifactId>
-      <version>${log4j.version}</version>
       <scope>test</scope>
     </dependency>
     <dependency>

httpclient5/src/main/java/org/apache/hc/client5/http/impl/DefaultAuthenticationStrategy.java

@@ -48,8 +48,8 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 import org.apache.hc.core5.http.config.Lookup;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default implementation of {@link AuthenticationStrategy}
@@ -59,7 +59,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class DefaultAuthenticationStrategy implements AuthenticationStrategy {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public static final DefaultAuthenticationStrategy INSTANCE = new DefaultAuthenticationStrategy();
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/InMemoryDnsResolver.java

@@ -34,8 +34,8 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.hc.client5.http.DnsResolver;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * In-memory {@link DnsResolver} implementation.
@@ -45,7 +45,7 @@ import org.apache.logging.log4j.Logger;
 public class InMemoryDnsResolver implements DnsResolver {
 
     /** Logger associated to this class. */
-    private final Logger log = LogManager.getLogger(InMemoryDnsResolver.class);
+    private final Logger log = LoggerFactory.getLogger(InMemoryDnsResolver.class);
 
     /**
      * In-memory collection that will hold the associations between a host name

httpclient5/src/main/java/org/apache/hc/client5/http/impl/Wire.java

@@ -31,7 +31,7 @@ import java.nio.ByteBuffer;
 
 import org.apache.hc.core5.annotation.Internal;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 @Internal
 public class Wire {

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AbstractHttpAsyncClientBase.java

@@ -40,14 +40,14 @@ import org.apache.hc.core5.reactor.DefaultConnectingIOReactor;
 import org.apache.hc.core5.reactor.ExceptionEvent;
 import org.apache.hc.core5.reactor.IOReactorStatus;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 abstract class AbstractHttpAsyncClientBase extends CloseableHttpAsyncClient {
 
     enum Status { READY, RUNNING, TERMINATED }
 
-    final Logger log = LogManager.getLogger(getClass());
+    final Logger log = LoggerFactory.getLogger(getClass());
 
     private final AsyncPushConsumerRegistry pushConsumerRegistry;
     private final DefaultConnectingIOReactor ioReactor;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncConnectExec.java

@@ -63,8 +63,8 @@ import org.apache.hc.core5.http.nio.AsyncEntityProducer;
 import org.apache.hc.core5.http.protocol.HttpCoreContext;
 import org.apache.hc.core5.http.protocol.HttpProcessor;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the HTTP request execution chain
@@ -76,7 +76,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
 public final class AsyncConnectExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpProcessor proxyHttpProcessor;
     private final AuthenticationStrategy proxyAuthStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncProtocolExec.java

@@ -64,8 +64,8 @@ import org.apache.hc.core5.http.protocol.HttpCoreContext;
 import org.apache.hc.core5.http.protocol.HttpProcessor;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the request execution chain that is responsible
@@ -80,7 +80,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class AsyncProtocolExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpProcessor httpProcessor;
     private final AuthenticationStrategy targetAuthStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncRedirectExec.java

@@ -55,12 +55,12 @@ import org.apache.hc.core5.http.message.BasicHttpRequest;
 import org.apache.hc.core5.http.nio.AsyncDataConsumer;
 import org.apache.hc.core5.http.nio.AsyncEntityProducer;
 import org.apache.hc.core5.util.LangUtils;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AsyncRedirectExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpRoutePlanner routePlanner;
     private final RedirectStrategy redirectStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncRetryExec.java

@@ -42,12 +42,12 @@ import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.nio.AsyncDataConsumer;
 import org.apache.hc.core5.http.nio.AsyncEntityProducer;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AsyncRetryExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpRequestRetryHandler retryHandler;
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/Http2AsyncClientEventHandlerFactory.java

@@ -48,8 +48,8 @@ import org.apache.hc.core5.reactor.IOEventHandler;
 import org.apache.hc.core5.reactor.IOEventHandlerFactory;
 import org.apache.hc.core5.reactor.TlsCapableIOSession;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @since 5.0
@@ -57,11 +57,11 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class Http2AsyncClientEventHandlerFactory implements IOEventHandlerFactory {
 
-    private final Logger wireLog = LogManager.getLogger("org.apache.hc.client5.http.wire");
+    private final Logger wireLog = LoggerFactory.getLogger("org.apache.hc.client5.http.wire");
-    private final Logger headerLog = LogManager.getLogger("org.apache.hc.client5.http.headers");
+    private final Logger headerLog = LoggerFactory.getLogger("org.apache.hc.client5.http.headers");
-    private final Logger frameLog = LogManager.getLogger("org.apache.hc.client5.http2.frame");
+    private final Logger frameLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.frame");
-    private final Logger framePayloadLog = LogManager.getLogger("org.apache.hc.client5.http2.frame.payload");
+    private final Logger framePayloadLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.frame.payload");
-    private final Logger flowCtrlLog = LogManager.getLogger("org.apache.hc.client5.http2.flow");
+    private final Logger flowCtrlLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.flow");
 
     private final HttpProcessor httpProcessor;
     private final HandlerFactory<AsyncPushConsumer> exchangeHandlerFactory;
@@ -81,7 +81,7 @@ class Http2AsyncClientEventHandlerFactory implements IOEventHandlerFactory {
 
     @Override
     public IOEventHandler createHandler(final TlsCapableIOSession ioSession, final Object attachment) {
-        final Logger sessionLog = LogManager.getLogger(ioSession.getClass());
+        final Logger sessionLog = LoggerFactory.getLogger(ioSession.getClass());
         if (sessionLog.isDebugEnabled()
                 || wireLog.isDebugEnabled()
                 || headerLog.isDebugEnabled()

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/Http2AsyncMainClientExec.java

@@ -50,12 +50,12 @@ import org.apache.hc.core5.http.nio.AsyncEntityProducer;
 import org.apache.hc.core5.http.nio.CapacityChannel;
 import org.apache.hc.core5.http.nio.DataStreamChannel;
 import org.apache.hc.core5.http.nio.RequestChannel;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class Http2AsyncMainClientExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     @Override
     public void execute(

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientEventHandlerFactory.java

@@ -64,8 +64,8 @@ import org.apache.hc.core5.reactor.IOEventHandler;
 import org.apache.hc.core5.reactor.IOEventHandlerFactory;
 import org.apache.hc.core5.reactor.TlsCapableIOSession;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @since 5.0
@@ -73,12 +73,12 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class HttpAsyncClientEventHandlerFactory implements IOEventHandlerFactory {
 
-    private final Logger streamLog = LogManager.getLogger(InternalHttpAsyncClient.class);
+    private final Logger streamLog = LoggerFactory.getLogger(InternalHttpAsyncClient.class);
-    private final Logger wireLog = LogManager.getLogger("org.apache.hc.client5.http.wire");
+    private final Logger wireLog = LoggerFactory.getLogger("org.apache.hc.client5.http.wire");
-    private final Logger headerLog = LogManager.getLogger("org.apache.hc.client5.http.headers");
+    private final Logger headerLog = LoggerFactory.getLogger("org.apache.hc.client5.http.headers");
-    private final Logger frameLog = LogManager.getLogger("org.apache.hc.client5.http2.frame");
+    private final Logger frameLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.frame");
-    private final Logger framePayloadLog = LogManager.getLogger("org.apache.hc.client5.http2.frame.payload");
+    private final Logger framePayloadLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.frame.payload");
-    private final Logger flowCtrlLog = LogManager.getLogger("org.apache.hc.client5.http2.flow");
+    private final Logger flowCtrlLog = LoggerFactory.getLogger("org.apache.hc.client5.http2.flow");
 
     private final HttpProcessor httpProcessor;
     private final HandlerFactory<AsyncPushConsumer> exchangeHandlerFactory;
@@ -111,7 +111,7 @@ class HttpAsyncClientEventHandlerFactory implements IOEventHandlerFactory {
 
     @Override
     public IOEventHandler createHandler(final TlsCapableIOSession ioSession, final Object attachment) {
-        final Logger sessionLog = LogManager.getLogger(ioSession.getClass());
+        final Logger sessionLog = LoggerFactory.getLogger(ioSession.getClass());
         if (sessionLog.isDebugEnabled()
                 || streamLog.isDebugEnabled()
                 || wireLog.isDebugEnabled()

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncMainClientExec.java

@@ -55,12 +55,12 @@ import org.apache.hc.core5.http.nio.CapacityChannel;
 import org.apache.hc.core5.http.nio.DataStreamChannel;
 import org.apache.hc.core5.http.nio.RequestChannel;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class HttpAsyncMainClientExec implements AsyncExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final ConnectionKeepAliveStrategy keepAliveStrategy;
     private final UserTokenHandler userTokenHandler;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalHttp2AsyncExecRuntime.java

@@ -45,7 +45,7 @@ import org.apache.hc.core5.http2.nio.pool.H2ConnPool;
 import org.apache.hc.core5.io.ShutdownType;
 import org.apache.hc.core5.reactor.IOSession;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 class InternalHttp2AsyncExecRuntime implements AsyncExecRuntime {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalHttpAsyncExecRuntime.java

@@ -45,7 +45,7 @@ import org.apache.hc.core5.http.nio.AsyncClientExchangeHandler;
 import org.apache.hc.core5.http2.HttpVersionPolicy;
 import org.apache.hc.core5.reactor.ConnectionInitiator;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 class InternalHttpAsyncExecRuntime implements AsyncExecRuntime {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/LogAppendable.java

@@ -29,7 +29,7 @@ package org.apache.hc.client5.http.impl.async;
 
 import java.io.IOException;
 
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 public final class LogAppendable implements Appendable {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/LoggingAsyncClientExchangeHandler.java

@@ -42,7 +42,7 @@ import org.apache.hc.core5.http.nio.CapacityChannel;
 import org.apache.hc.core5.http.nio.DataStreamChannel;
 import org.apache.hc.core5.http.nio.RequestChannel;
 import org.apache.hc.core5.util.Identifiable;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 final class LoggingAsyncClientExchangeHandler implements AsyncClientExchangeHandler, Identifiable {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/LoggingIOSession.java

@@ -44,7 +44,7 @@ import org.apache.hc.core5.reactor.ssl.SSLBufferManagement;
 import org.apache.hc.core5.reactor.ssl.SSLSessionInitializer;
 import org.apache.hc.core5.reactor.ssl.SSLSessionVerifier;
 import org.apache.hc.core5.reactor.ssl.TlsDetails;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 class LoggingIOSession implements TlsCapableIOSession {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/BasicAuthCache.java

@@ -44,8 +44,8 @@ import org.apache.hc.core5.annotation.Contract;
 import org.apache.hc.core5.annotation.ThreadingBehavior;
 import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default implementation of {@link AuthCache}. This implements
@@ -60,7 +60,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL)
 public class BasicAuthCache implements AuthCache {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final Map<HttpHost, byte[]> map;
     private final SchemePortResolver schemePortResolver;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/CredSspScheme.java

@@ -60,8 +60,8 @@ import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * <p>
@@ -83,7 +83,7 @@ public class CredSspScheme implements AuthScheme
     private static final Charset UNICODE_LITTLE_UNMARKED = Charset.forName( "UnicodeLittleUnmarked" );
     public static final String SCHEME_NAME = "CredSSP";
 
-    private final Logger log = LogManager.getLogger( CredSspScheme.class );
+    private final Logger log = LoggerFactory.getLogger( CredSspScheme.class );
 
     enum State
     {

httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/GGSSchemeBase.java

@@ -47,14 +47,14 @@ import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.ietf.jgss.GSSContext;
 import org.ietf.jgss.GSSCredential;
 import org.ietf.jgss.GSSException;
 import org.ietf.jgss.GSSManager;
 import org.ietf.jgss.GSSName;
 import org.ietf.jgss.Oid;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @since 4.2
@@ -68,7 +68,7 @@ public abstract class GGSSchemeBase implements AuthScheme {
         FAILED,
     }
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final KerberosConfig config;
     private final DnsResolver dnsResolver;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/HttpAuthenticator.java

@@ -58,8 +58,8 @@ import org.apache.hc.core5.http.message.ParserCursor;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Asserts;
 import org.apache.hc.core5.util.CharArrayBuffer;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @since 4.3
@@ -71,7 +71,7 @@ public class HttpAuthenticator {
 
     public HttpAuthenticator(final Logger log) {
         super();
-        this.log = log != null ? log : LogManager.getLogger(getClass());
+        this.log = log != null ? log : LoggerFactory.getLogger(getClass());
         this.parser = new AuthChallengeParser();
     }
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/CloseableHttpClient.java

@@ -45,8 +45,8 @@ import org.apache.hc.core5.http.io.HttpClientResponseHandler;
 import org.apache.hc.core5.http.io.entity.EntityUtils;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Base implementation of {@link HttpClient} that also implements {@link Closeable}.
@@ -56,7 +56,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE)
 public abstract class CloseableHttpClient implements HttpClient, Closeable {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     protected abstract CloseableHttpResponse doExecute(HttpHost target, ClassicHttpRequest request,
                                                      HttpContext context) throws IOException;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/ConnectExec.java

@@ -60,8 +60,8 @@ import org.apache.hc.core5.http.message.BasicClassicHttpRequest;
 import org.apache.hc.core5.http.message.StatusLine;
 import org.apache.hc.core5.http.protocol.HttpProcessor;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the HTTP request execution chain
@@ -73,7 +73,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
 public final class ConnectExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final ConnectionReuseStrategy reuseStrategy;
     private final HttpProcessor proxyHttpProcessor;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/InternalExecRuntime.java

@@ -50,7 +50,7 @@ import org.apache.hc.core5.io.ShutdownType;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 class InternalExecRuntime implements ExecRuntime, Cancellable {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/InternalHttpClient.java

@@ -60,8 +60,8 @@ import org.apache.hc.core5.http.protocol.BasicHttpContext;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Internal class.
@@ -71,7 +71,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL)
 class InternalHttpClient extends CloseableHttpClient implements Configurable {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpClientConnectionManager connManager;
     private final HttpRequestExecutor requestExecutor;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/MainClientExec.java

@@ -48,8 +48,8 @@ import org.apache.hc.core5.http.HttpException;
 import org.apache.hc.core5.http.message.RequestLine;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * The last request executor in the HTTP request execution chain
@@ -61,7 +61,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
 final class MainClientExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final ConnectionReuseStrategy reuseStrategy;
     private final ConnectionKeepAliveStrategy keepAliveStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/MinimalHttpClient.java

@@ -64,8 +64,8 @@ import org.apache.hc.core5.http.protocol.RequestUserAgent;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.VersionInfo;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Internal class.
@@ -75,7 +75,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE)
 public class MinimalHttpClient extends CloseableHttpClient {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpClientConnectionManager connManager;
     private final ConnectionReuseStrategy reuseStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/ProtocolExec.java

@@ -63,8 +63,8 @@ import org.apache.hc.core5.http.protocol.HttpCoreContext;
 import org.apache.hc.core5.http.protocol.HttpProcessor;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the request execution chain that is responsible
@@ -80,7 +80,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 final class ProtocolExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpProcessor httpProcessor;
     private final AuthenticationStrategy targetAuthStrategy;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/RedirectExec.java

@@ -58,8 +58,8 @@ import org.apache.hc.core5.http.ProtocolException;
 import org.apache.hc.core5.http.io.entity.EntityUtils;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.LangUtils;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the request execution chain that is responsible
@@ -75,7 +75,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL)
 final class RedirectExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final RedirectStrategy redirectStrategy;
     private final HttpRoutePlanner routePlanner;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/RetryExec.java

@@ -42,8 +42,8 @@ import org.apache.hc.core5.http.HttpEntity;
 import org.apache.hc.core5.http.HttpException;
 import org.apache.hc.core5.http.NoHttpResponseException;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the request execution chain that is responsible
@@ -60,7 +60,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
 final class RetryExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpRequestRetryHandler retryHandler;
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/ServiceUnavailableRetryExec.java

@@ -41,8 +41,8 @@ import org.apache.hc.core5.http.ClassicHttpResponse;
 import org.apache.hc.core5.http.HttpEntity;
 import org.apache.hc.core5.http.HttpException;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request executor in the request execution chain that is responsible
@@ -59,7 +59,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
 final class ServiceUnavailableRetryExec implements ExecChainHandler {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final ServiceUnavailableRetryStrategy retryStrategy;
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/BasicHttpClientConnectionManager.java

@@ -66,8 +66,8 @@ import org.apache.hc.core5.util.Asserts;
 import org.apache.hc.core5.util.LangUtils;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * A connection manager for a single connection. This connection manager maintains only one active
@@ -90,7 +90,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE)
 public class BasicHttpClientConnectionManager implements HttpClientConnectionManager {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final HttpClientConnectionOperator connectionOperator;
     private final HttpConnectionFactory<ManagedHttpClientConnection> connFactory;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/DefaultHttpClientConnectionOperator.java

@@ -56,8 +56,8 @@ import org.apache.hc.core5.http.config.SocketConfig;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default implementation of {@link HttpClientConnectionOperator} used as default in Http client,
@@ -72,7 +72,7 @@ public class DefaultHttpClientConnectionOperator implements HttpClientConnection
 
     static final String SOCKET_FACTORY_REGISTRY = "http.socket-factory-registry";
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final Lookup<ConnectionSocketFactory> socketFactoryRegistry;
     private final SchemePortResolver schemePortResolver;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/DefaultManagedHttpClientConnection.java

@@ -51,8 +51,8 @@ import org.apache.hc.core5.http.message.RequestLine;
 import org.apache.hc.core5.http.message.StatusLine;
 import org.apache.hc.core5.io.ShutdownType;
 import org.apache.hc.core5.util.Identifiable;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default {@link ManagedHttpClientConnection} implementation.
@@ -62,9 +62,9 @@ import org.apache.logging.log4j.Logger;
 final class DefaultManagedHttpClientConnection
         extends DefaultBHttpClientConnection implements ManagedHttpClientConnection, Identifiable {
 
-    private final Logger log = LogManager.getLogger(DefaultManagedHttpClientConnection.class);
+    private final Logger log = LoggerFactory.getLogger(DefaultManagedHttpClientConnection.class);
-    private final Logger headerlog = LogManager.getLogger("org.apache.hc.client5.http.headers");
+    private final Logger headerlog = LoggerFactory.getLogger("org.apache.hc.client5.http.headers");
-    private final Logger wirelog = LogManager.getLogger("org.apache.hc.client5.http.wire");
+    private final Logger wirelog = LoggerFactory.getLogger("org.apache.hc.client5.http.wire");
 
     private final String id;
     private final AtomicBoolean closed;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/LenientHttpResponseParser.java

@@ -36,8 +36,8 @@ import org.apache.hc.core5.http.config.H1Config;
 import org.apache.hc.core5.http.impl.io.DefaultHttpResponseParser;
 import org.apache.hc.core5.http.message.LineParser;
 import org.apache.hc.core5.util.CharArrayBuffer;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Lenient HTTP response parser implementation that can skip malformed data until
@@ -47,7 +47,7 @@ import org.apache.logging.log4j.Logger;
  */
 public class LenientHttpResponseParser extends DefaultHttpResponseParser {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     /**
      * Creates new instance of DefaultHttpResponseParser.

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/LoggingSocketHolder.java

@@ -34,7 +34,7 @@ import java.net.Socket;
 
 import org.apache.hc.client5.http.impl.Wire;
 import org.apache.hc.core5.http.impl.io.SocketHolder;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.Logger;
 
 class LoggingSocketHolder extends SocketHolder {
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/PoolingHttpClientConnectionManager.java

@@ -74,8 +74,8 @@ import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.Asserts;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * {@code ClientConnectionPoolManager} maintains a pool of
@@ -105,7 +105,7 @@ import org.apache.logging.log4j.Logger;
 public class PoolingHttpClientConnectionManager
     implements HttpClientConnectionManager, ConnPoolControl<HttpRoute> {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 25;
     public static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/nio/DefaultManagedAsyncClientConnection.java

@@ -52,8 +52,8 @@ import org.apache.hc.core5.reactor.ssl.SSLSessionVerifier;
 import org.apache.hc.core5.reactor.ssl.TlsDetails;
 import org.apache.hc.core5.reactor.ssl.TransportSecurityLayer;
 import org.apache.hc.core5.util.Identifiable;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default {@link ManagedAsyncClientConnection} implementation.
@@ -63,7 +63,7 @@ import org.apache.logging.log4j.Logger;
 @Internal
 final class DefaultManagedAsyncClientConnection implements ManagedAsyncClientConnection, Identifiable {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final IOSession ioSession;
     private final int socketTimeout;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/nio/PoolingAsyncClientConnectionManager.java

@@ -77,8 +77,8 @@ import org.apache.hc.core5.util.Asserts;
 import org.apache.hc.core5.util.Identifiable;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * {@code PoolingAsyncClientConnectionManager} maintains a pool of non-blocking
@@ -101,7 +101,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.SAFE_CONDITIONAL)
 public class PoolingAsyncClientConnectionManager implements AsyncClientConnectionManager, ConnPoolControl<HttpRoute> {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 25;
     public static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5;

httpclient5/src/main/java/org/apache/hc/client5/http/protocol/RequestAddCookies.java

@@ -52,8 +52,8 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TextUtils;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request interceptor that matches cookies available in the current
@@ -65,7 +65,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class RequestAddCookies implements HttpRequestInterceptor {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public RequestAddCookies() {
         super();

httpclient5/src/main/java/org/apache/hc/client5/http/protocol/RequestAuthCache.java

@@ -44,8 +44,8 @@ import org.apache.hc.core5.http.HttpRequestInterceptor;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.net.URIAuthority;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Request interceptor that can preemptively authenticate against known hosts,
@@ -57,7 +57,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class RequestAuthCache implements HttpRequestInterceptor {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public RequestAuthCache() {
         super();

httpclient5/src/main/java/org/apache/hc/client5/http/protocol/RequestClientConnControl.java

@@ -40,8 +40,8 @@ import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpRequestInterceptor;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * This protocol interceptor is responsible for adding {@code Connection}
@@ -53,7 +53,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class RequestClientConnControl implements HttpRequestInterceptor {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private static final String PROXY_CONN_DIRECTIVE = "Proxy-Connection";
 

httpclient5/src/main/java/org/apache/hc/client5/http/protocol/ResponseProcessCookies.java

@@ -45,8 +45,8 @@ import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.HttpResponseInterceptor;
 import org.apache.hc.core5.http.protocol.HttpContext;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Response interceptor that populates the current {@link CookieStore} with data
@@ -57,7 +57,7 @@ import org.apache.logging.log4j.Logger;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class ResponseProcessCookies implements HttpResponseInterceptor {
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     public ResponseProcessCookies() {
         super();

httpclient5/src/main/java/org/apache/hc/client5/http/psl/PublicSuffixMatcherLoader.java

@@ -39,8 +39,8 @@ import java.util.List;
 import org.apache.hc.core5.annotation.Contract;
 import org.apache.hc.core5.annotation.ThreadingBehavior;
 import org.apache.hc.core5.util.Args;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * {@link PublicSuffixMatcher} loader.
@@ -83,7 +83,7 @@ public final class PublicSuffixMatcherLoader {
                             DEFAULT_INSTANCE = load(url);
                         } catch (final IOException ex) {
                             // Should never happen
-                            final Logger log = LogManager.getLogger(PublicSuffixMatcherLoader.class);
+                            final Logger log = LoggerFactory.getLogger(PublicSuffixMatcherLoader.class);
                             if (log.isWarnEnabled()) {
                                 log.warn("Failure loading public suffix list from default resource", ex);
                             }

httpclient5/src/main/java/org/apache/hc/client5/http/ssl/DefaultHostnameVerifier.java

@@ -55,8 +55,8 @@ import org.apache.hc.client5.http.psl.PublicSuffixMatcher;
 import org.apache.hc.core5.annotation.Contract;
 import org.apache.hc.core5.annotation.ThreadingBehavior;
 import org.apache.hc.core5.net.InetAddressUtils;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default {@link javax.net.ssl.HostnameVerifier} implementation.
@@ -78,7 +78,7 @@ public final class DefaultHostnameVerifier implements HttpClientHostnameVerifier
 
     }
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final PublicSuffixMatcher publicSuffixMatcher;
 

httpclient5/src/main/java/org/apache/hc/client5/http/ssl/H2TlsStrategy.java

@@ -58,8 +58,8 @@ import org.apache.hc.core5.reactor.ssl.TransportSecurityLayer;
 import org.apache.hc.core5.ssl.SSLContexts;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TextUtils;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Default SSL upgrade strategy for non-blocking connections.
@@ -102,7 +102,7 @@ public class H2TlsStrategy implements TlsStrategy {
                 getDefaultHostnameVerifier());
     }
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final SSLContext sslContext;
     private final String[] supportedProtocols;

httpclient5/src/main/java/org/apache/hc/client5/http/ssl/SSLConnectionSocketFactory.java

@@ -58,8 +58,8 @@ import org.apache.hc.core5.ssl.SSLInitializationException;
 import org.apache.hc.core5.util.Args;
 import org.apache.hc.core5.util.TextUtils;
 import org.apache.hc.core5.util.TimeValue;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
-import org.apache.logging.log4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Layered socket factory for TLS/SSL connections.
@@ -142,7 +142,7 @@ public class SSLConnectionSocketFactory implements LayeredConnectionSocketFactor
     public static final String TLS   = "TLS";
     public static final String SSL   = "SSL";
 
-    private final Logger log = LogManager.getLogger(getClass());
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     /**
      * @since 4.4

httpclient5/src/test/java/org/apache/hc/client5/http/impl/classic/TestInternalExecRuntime.java

@@ -44,13 +44,13 @@ import org.apache.hc.core5.http.impl.io.HttpRequestExecutor;
 import org.apache.hc.core5.io.ShutdownType;
 import org.apache.hc.core5.util.TimeValue;
 import org.apache.hc.core5.util.Timeout;
-import org.apache.logging.log4j.Logger;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
+import org.slf4j.Logger;
 
 @SuppressWarnings({"static-access"}) // test code
 public class TestInternalExecRuntime {

pom.xml

@@ -73,7 +73,7 @@
     <commons-codec.version>1.10</commons-codec.version>
     <ehcache.version>3.4.0</ehcache.version>
     <memcached.version>2.12.3</memcached.version>
-    <slf4j.version>1.7.13</slf4j.version>
+    <slf4j.version>1.7.25</slf4j.version>
     <junit.version>4.12</junit.version>
     <easymock.version>2.5.2</easymock.version>
     <mockito.version>2.7.22</mockito.version>
@@ -98,22 +98,26 @@
         <artifactId>httpcore5-testing</artifactId>
         <version>${httpcore.version}</version>
       </dependency>
+      <dependency>
+        <groupId>org.slf4j</groupId>
+        <artifactId>slf4j-api</artifactId>
+        <version>${slf4j.version}</version>
+      </dependency>
       <dependency>
         <groupId>org.apache.logging.log4j</groupId>
         <artifactId>log4j-api</artifactId>
         <version>${log4j.version}</version>
       </dependency>
+      <!-- TODO remove after upgrade to HttpCore 5.0b2 -->
+      <dependency>
+        <groupId>org.apache.logging.log4j</groupId>
+        <artifactId>log4j-slf4j-impl</artifactId>
+        <version>${log4j.version}</version>
+      </dependency>
       <dependency>
         <groupId>org.apache.logging.log4j</groupId>
         <artifactId>log4j-core</artifactId>
         <version>${log4j.version}</version>
-        <scope>test</scope>
-      </dependency>
-      <dependency>
-        <groupId>org.apache.logging.log4j</groupId>
-        <artifactId>log4j-slf4j-impl</artifactId>
-        <version>${log4j.version}</version>
-        <scope>test</scope>
       </dependency>
       <dependency>
         <groupId>commons-codec</groupId>