apache · rschmitt · Jan 29, 2026 · Jan 23, 2026
diff --git a/httpclient5-fluent/src/main/java/org/apache/hc/client5/http/fluent/Executor.java b/httpclient5-fluent/src/main/java/org/apache/hc/client5/http/fluent/Executor.java
@@ -77,14 +77,12 @@ static CloseableHttpClient GET_CLASSIC_CLIENT() {
             if (CLIENT == null) {
                 CLIENT = HttpClientBuilder.create()
                         .setConnectionManager(PoolingHttpClientConnectionManagerBuilder.create()
-                                .useSystemProperties()
                                 .setMaxConnPerRoute(100)
                                 .setMaxConnTotal(200)
                                 .setDefaultConnectionConfig(ConnectionConfig.custom()
                                         .setValidateAfterInactivity(TimeValue.ofSeconds(10))
                                         .build())
                                 .build())
-                        .useSystemProperties()
                         .evictExpiredConnections()
                         .evictIdleConnections(TimeValue.ofMinutes(1))
                         .build();
@@ -105,15 +103,13 @@ static CloseableHttpClient GET_ASYNC_CLIENT() {
             if (ASYNC_CLIENT == null) {
                 ASYNC_CLIENT = new ClassicToAsyncAdaptor(HttpAsyncClientBuilder.create()
                         .setConnectionManager(PoolingAsyncClientConnectionManagerBuilder.create()
-                                .useSystemProperties()
                                 .setMaxConnPerRoute(100)
                                 .setMaxConnTotal(200)
                                 .setMessageMultiplexing(true)
                                 .setDefaultConnectionConfig(ConnectionConfig.custom()
                                         .setValidateAfterInactivity(TimeValue.ofSeconds(10))
                                         .build())
                                 .build())
-                        .useSystemProperties()
                         .evictExpiredConnections()
                         .evictIdleConnections(TimeValue.ofMinutes(1))
                         .build(), Timeout.ofMinutes(5));

diff --git a/httpclient5-sse/src/main/java/org/apache/hc/client5/http/sse/SseExecutor.java b/httpclient5-sse/src/main/java/org/apache/hc/client5/http/sse/SseExecutor.java
@@ -103,12 +103,10 @@ static CloseableHttpAsyncClient getSharedClient() {
             if (c == null) {
                 c = HttpAsyncClientBuilder.create()
                         .setConnectionManager(PoolingAsyncClientConnectionManagerBuilder.create()
-                                .useSystemProperties()
                                 .setMaxConnPerRoute(100)
                                 .setMaxConnTotal(200)
                                 .setMessageMultiplexing(true)
                                 .build())
-                        .useSystemProperties()
                         .evictExpiredConnections()
                         .evictIdleConnections(TimeValue.ofMinutes(1))
                         .build();

diff --git a/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/ClientSseExample.java b/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/ClientSseExample.java
@@ -67,7 +67,6 @@ public static void main(final String[] args) throws Exception {
 
         final PoolingAsyncClientConnectionManager connMgr =
                 PoolingAsyncClientConnectionManagerBuilder.create()
-                        .useSystemProperties()
                         .setMessageMultiplexing(true)      // HTTP/2 stream multiplexing
                         .setMaxConnPerRoute(32)
                         .setMaxConnTotal(256)
@@ -84,7 +83,6 @@ public static void main(final String[] args) throws Exception {
                         .setPushEnabled(false)
                         .setMaxConcurrentStreams(256)
                         .build())
-                .useSystemProperties()
                 .evictExpiredConnections()
                 .evictIdleConnections(TimeValue.ofMinutes(1))
                 .build();

diff --git a/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/ClientSseH2Example.java b/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/ClientSseH2Example.java
@@ -145,7 +145,6 @@ public static void main(final String[] args) throws Exception {
 
         final PoolingAsyncClientConnectionManager connMgr =
                 PoolingAsyncClientConnectionManagerBuilder.create()
-                        .useSystemProperties()
                         .setMessageMultiplexing(true)
                         .setMaxConnPerRoute(1)
                         .setMaxConnTotal(4)
@@ -161,7 +160,6 @@ public static void main(final String[] args) throws Exception {
                         .setPushEnabled(false)
                         .setMaxConcurrentStreams(Math.max(64, streamCount * 8))
                         .build())
-                .useSystemProperties()
                 .evictExpiredConnections()
                 .evictIdleConnections(TimeValue.ofMinutes(1))
                 .build();

diff --git a/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/SsePerfClient.java b/httpclient5-sse/src/test/java/org/apache/hc/client5/http/sse/example/SsePerfClient.java
@@ -107,7 +107,6 @@ public static void main(final String[] args) throws Exception {
 
         final PoolingAsyncClientConnectionManager connMgr =
                 PoolingAsyncClientConnectionManagerBuilder.create()
-                        .useSystemProperties()
                         .setMessageMultiplexing(true)
                         .setMaxConnPerRoute(16)
                         .setMaxConnTotal(16)
@@ -123,7 +122,6 @@ public static void main(final String[] args) throws Exception {
                         .setPushEnabled(false)
                         .setMaxConcurrentStreams(Math.max(64, streams * 4))
                         .build())
-                .useSystemProperties()
                 .evictExpiredConnections()
                 .evictIdleConnections(TimeValue.ofMinutes(1))
                 .build();

diff --git a/...5-sse/src/test/java/org/apache/hc/client5/http/sse/example/performance/SsePerfClient.java b/...5-sse/src/test/java/org/apache/hc/client5/http/sse/example/performance/SsePerfClient.java
@@ -90,7 +90,6 @@ public static void main(final String[] args) throws Exception {
 
         final PoolingAsyncClientConnectionManager connMgr =
                 PoolingAsyncClientConnectionManagerBuilder.create()
-                        .useSystemProperties()
                         .setMessageMultiplexing(true) // enable H2 multiplexing if negotiated
                         .setMaxConnPerRoute(Math.max(64, connections))
                         .setMaxConnTotal(Math.max(128, connections))
@@ -107,7 +106,6 @@ public static void main(final String[] args) throws Exception {
                         .setPushEnabled(false)
                         .setMaxConcurrentStreams(512)
                         .build())
-                .useSystemProperties()
                 .evictExpiredConnections()
                 .evictIdleConnections(TimeValue.ofMinutes(1))
                 .build();

diff --git a/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/H2AsyncClientBuilder.java b/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/H2AsyncClientBuilder.java
@@ -55,7 +55,6 @@
 import org.apache.hc.client5.http.impl.DefaultHttpRequestRetryStrategy;
 import org.apache.hc.client5.http.impl.DefaultRedirectStrategy;
 import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
-import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
 import org.apache.hc.client5.http.impl.auth.BasicSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.BearerSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.DigestSchemeFactory;
@@ -201,7 +200,6 @@ private ExecInterceptorEntry(
     private boolean evictIdleConnections;
     private TimeValue maxIdleTime;
 
-    private boolean systemProperties;
     private boolean automaticRetriesDisabled;
     private boolean redirectHandlingDisabled;
     private boolean cookieManagementDisabled;
@@ -669,13 +667,13 @@ public final H2AsyncClientBuilder setDefaultConnectionConfig(final ConnectionCon
     }
 
     /**
-     * Use system properties when creating and configuring default
-     * implementations.
+     * Ignored.
      *
+     * @deprecated This method is now redundant and calls to it can be removed.
      * @return this instance.
      */
+    @Deprecated
     public final H2AsyncClientBuilder useSystemProperties() {
-        this.systemProperties = true;
         return this;
     }
 
@@ -964,20 +962,12 @@ public CloseableHttpAsyncClient build() {
 
         CredentialsProvider credentialsProviderCopy = this.credentialsProvider;
         if (credentialsProviderCopy == null) {
-            if (systemProperties) {
-                credentialsProviderCopy = new SystemDefaultCredentialsProvider();
-            } else {
-                credentialsProviderCopy = new BasicCredentialsProvider();
-            }
+            credentialsProviderCopy = new SystemDefaultCredentialsProvider();
         }
 
         TlsStrategy tlsStrategyCopy = this.tlsStrategy;
         if (tlsStrategyCopy == null) {
-            if (systemProperties) {
-                tlsStrategyCopy = DefaultClientTlsStrategy.createSystemDefault();
-            } else {
-                tlsStrategyCopy = DefaultClientTlsStrategy.createDefault();
-            }
+            tlsStrategyCopy = DefaultClientTlsStrategy.createDefault();
         }
 
         final MultihomeConnectionInitiator connectionInitiator = new MultihomeConnectionInitiator(ioReactor, dnsResolver);

diff --git a/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java b/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java
@@ -65,15 +65,13 @@
 import org.apache.hc.client5.http.impl.DefaultUserTokenHandler;
 import org.apache.hc.client5.http.impl.IdleConnectionEvictor;
 import org.apache.hc.client5.http.impl.NoopUserTokenHandler;
-import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
 import org.apache.hc.client5.http.impl.auth.BasicSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.BearerSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.DigestSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.ScramSchemeFactory;
 import org.apache.hc.client5.http.impl.auth.SystemDefaultCredentialsProvider;
 import org.apache.hc.client5.http.impl.nio.PoolingAsyncClientConnectionManagerBuilder;
 import org.apache.hc.client5.http.impl.routing.DefaultProxyRoutePlanner;
-import org.apache.hc.client5.http.impl.routing.DefaultRoutePlanner;
 import org.apache.hc.client5.http.impl.routing.SystemDefaultRoutePlanner;
 import org.apache.hc.client5.http.nio.AsyncClientConnectionManager;
 import org.apache.hc.client5.http.protocol.H2RequestPriority;
@@ -137,20 +135,6 @@
  * separate connections leased from the connection pool.
  * </p>
  * <p>
- * When a particular component is not explicitly set this class will
- * use its default implementation. System properties will be taken
- * into account when configuring the default implementations when
- * {@link #useSystemProperties()} method is called prior to calling
- * {@link #build()}.
- * </p>
- * <ul>
- *  <li>http.proxyHost</li>
- *  <li>http.proxyPort</li>
- *  <li>https.proxyHost</li>
- *  <li>https.proxyPort</li>
- *  <li>http.nonProxyHosts</li>
- * </ul>
- * <p>
  * Please note that some settings used by this class can be mutually
  * exclusive and may not apply when building {@link CloseableHttpAsyncClient}
  * instances.
@@ -252,7 +236,6 @@ private ExecInterceptorEntry(
     private boolean evictIdleConnections;
     private TimeValue maxIdleTime;
 
-    private boolean systemProperties;
     private boolean automaticRetriesDisabled;
     private boolean redirectHandlingDisabled;
     private boolean cookieManagementDisabled;
@@ -776,13 +759,13 @@ public final HttpAsyncClientBuilder setDefaultRequestConfig(final RequestConfig
     }
 
     /**
-     * Use system properties when creating and configuring default
-     * implementations.
+     * Ignored.
      *
+     * @deprecated This method is now redundant and calls to it can be removed.
      * @return this instance.
      */
+    @Deprecated
     public final HttpAsyncClientBuilder useSystemProperties() {
-        this.systemProperties = true;
         return this;
     }
 
@@ -1010,11 +993,7 @@ public AsyncClientConnectionManager getConnManager() {
     public CloseableHttpAsyncClient build() {
         AsyncClientConnectionManager connManagerCopy = this.connManager;
         if (connManagerCopy == null) {
-            final PoolingAsyncClientConnectionManagerBuilder connectionManagerBuilder = PoolingAsyncClientConnectionManagerBuilder.create();
-            if (systemProperties) {
-                connectionManagerBuilder.useSystemProperties();
-            }
-            connManagerCopy = connectionManagerBuilder.build();
+            connManagerCopy = PoolingAsyncClientConnectionManagerBuilder.create().build();
         }
 
         ConnectionKeepAliveStrategy keepAliveStrategyCopy = this.keepAliveStrategy;
@@ -1166,11 +1145,9 @@ public CloseableHttpAsyncClient build() {
                 routePlannerCopy = new DefaultProxyRoutePlanner(proxy, schemePortResolverCopy);
             } else if (this.proxySelector != null) {
                 routePlannerCopy = new SystemDefaultRoutePlanner(schemePortResolverCopy, this.proxySelector);
-            } else if (systemProperties) {
+            } else {
                 final ProxySelector defaultProxySelector = ProxySelector.getDefault();
                 routePlannerCopy = new SystemDefaultRoutePlanner(schemePortResolverCopy, defaultProxySelector);
-            } else {
-                routePlannerCopy = new DefaultRoutePlanner(schemePortResolverCopy);
             }
         }
 
@@ -1276,11 +1253,7 @@ public CloseableHttpAsyncClient build() {
 
         CredentialsProvider credentialsProviderCopy = this.credentialsProvider;
         if (credentialsProviderCopy == null) {
-            if (systemProperties) {
-                credentialsProviderCopy = new SystemDefaultCredentialsProvider();
-            } else {
-                credentialsProviderCopy = new BasicCredentialsProvider();
-            }
+            credentialsProviderCopy = new SystemDefaultCredentialsProvider();
         }
 
         return new InternalHttpAsyncClient(

diff --git a/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClients.java b/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClients.java
@@ -89,9 +89,12 @@ public static CloseableHttpAsyncClient createDefault() {
     /**
      * Creates {@link CloseableHttpAsyncClient} instance with default
      * configuration and system properties.
+     *
+     * @deprecated This is now a synonym for {@link #createDefault}; call that instead.
      */
+    @Deprecated
     public static CloseableHttpAsyncClient createSystem() {
-        return HttpAsyncClientBuilder.create().useSystemProperties().build();
+        return createDefault();
     }
 
     /**
@@ -112,11 +115,13 @@ public static CloseableHttpAsyncClient createHttp2Default() {
     }
 
     /**
-     * Creates HTTP/2 {@link CloseableHttpAsyncClient} instance with default configuration and
-     * system properties optimized for HTTP/2 protocol and message multiplexing.
+     * Creates HTTP/2 {@link CloseableHttpAsyncClient} instance with default configuration.
+     *
+     * @deprecated This is now a synonym for {@link #createHttp2Default}; call that instead.
      */
+    @Deprecated
     public static CloseableHttpAsyncClient createHttp2System() {
-        return H2AsyncClientBuilder.create().useSystemProperties().build();
+        return createHttp2Default();
     }
 
     private static HttpProcessor createMinimalProtocolProcessor() {