HTTPCLIENT-1843 Plug Commons-Compress into HttpClient’s automatic

httpclient5-testing/src/test/java/org/apache/hc/client5/testing/sync/TestRedirects.java

@@ -646,8 +646,8 @@ public void handle(final ClassicHttpRequest request,
         Assertions.assertEquals(new URIBuilder().setHttpHost(target).setPath("/random/100").build(),
                 reqWrapper.getUri());
 
-        assertThat(values.poll(), CoreMatchers.equalTo("gzip, x-gzip, deflate"));
-        assertThat(values.poll(), CoreMatchers.equalTo("gzip, x-gzip, deflate"));
+        assertThat(values.poll(), CoreMatchers.equalTo("gzip, deflate, lz4-framed, lz4-block, bzip2, pack200, deflate64, x-gzip"));
+        assertThat(values.poll(), CoreMatchers.equalTo("gzip, deflate, lz4-framed, lz4-block, bzip2, pack200, deflate64, x-gzip"));
         assertThat(values.poll(), CoreMatchers.nullValue());
     }
 

httpclient5/pom.xml

@@ -108,6 +108,11 @@
       <artifactId>commons-io</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-compress</artifactId>
+      <optional>true</optional>
+    </dependency>
   </dependencies>
 
   <build>

httpclient5/src/main/java/org/apache/hc/client5/http/entity/BrotliInputStreamFactory.java

@@ -41,6 +41,17 @@
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class BrotliInputStreamFactory implements InputStreamFactory {
 
+    /**
+     * Canonical token for the deflate content-coding.
+     * @since 5.6
+     */
+    public static final String ENCODING = "br";
+
+    @Override
+    public String getContentEncoding() {
+        return ENCODING;
+    }
+
     /**
      * Default instance of {@link BrotliInputStreamFactory}.
      */

httpclient5/src/main/java/org/apache/hc/client5/http/entity/DeflateInputStreamFactory.java

@@ -41,6 +41,17 @@
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DeflateInputStreamFactory implements InputStreamFactory {
 
+    /**
+     * Canonical token for the deflate content-coding.
+     * @since 5.6
+     */
+    public static final String ENCODING = "deflate";
+
+    @Override
+    public String getContentEncoding() {
+        return ENCODING;
+    }
+
     /**
      * Default instance of {@link DeflateInputStreamFactory}.
      */

httpclient5/src/main/java/org/apache/hc/client5/http/entity/GZIPInputStreamFactory.java

@@ -42,6 +42,17 @@
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class GZIPInputStreamFactory implements InputStreamFactory {
 
+    /**
+     * Canonical token for the gzip content-coding.
+     * @since 5.6
+     */
+    public static final String ENCODING = "gzip";
+
+    @Override
+    public String getContentEncoding() {
+        return ENCODING;
+    }
+
     /**
      * Default instance of {@link GZIPInputStreamFactory}.
      */

httpclient5/src/main/java/org/apache/hc/client5/http/entity/InputStreamFactory.java

@@ -38,4 +38,21 @@ public interface InputStreamFactory {
 
     InputStream create(InputStream inputStream) throws IOException;
 
+    /**
+     * Returns the canonical {@code Content-Encoding} token handled by this
+     * factory (for example {@code "gzip"}, {@code "deflate"}, {@code "br"}).
+     * <p>
+     * Implementations that do <strong>not</strong> represent a HTTP
+     * content-decoder should simply inherit the default implementation,
+     * which returns an empty string.
+     *
+     * @return the lower-case encoding token, or an empty string when the
+     *         factory is not intended for HTTP content-decoding
+     *
+     * @since 5.6
+     */
+    default String getContentEncoding() {
+        return "";
+    }
+
 }

httpclient5/src/main/java/org/apache/hc/client5/http/entity/compress/CommonsCompressDecoderFactory.java

@@ -0,0 +1,117 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.hc.client5.http.entity.compress;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collections;
+import java.util.EnumMap;
+import java.util.Locale;
+import java.util.Map;
+
+import org.apache.commons.compress.compressors.CompressorException;
+import org.apache.commons.compress.compressors.CompressorStreamFactory;
+import org.apache.hc.client5.http.entity.InputStreamFactory;
+import org.apache.hc.core5.annotation.Contract;
+import org.apache.hc.core5.annotation.Internal;
+import org.apache.hc.core5.annotation.ThreadingBehavior;
+
+/**
+ * A factory for creating InputStream instances, utilizing Apache Commons Compress.
+ * This class is compiled with Commons Compress as an optional dependency, loading
+ * only when the library is present at runtime, avoiding mandatory inclusion in
+ * downstream builds.
+ * <p>
+ * <p>
+ * Some encodings require native helper JARs; runtime availability is checked
+ * using a lightweight Class.forName probe to register codecs only when helpers
+ * are present.
+ *
+ * @since 5.6
+ */
+@Internal
+@Contract(threading = ThreadingBehavior.STATELESS)
+final class CommonsCompressDecoderFactory implements InputStreamFactory {
+
+
+    /**
+     * Map of codings that need extra JARs → the fully‐qualified class we test for
+     */
+    private static final Map<ContentCoding, String> REQUIRED_CLASS_NAME;
+
+    static {
+        final Map<ContentCoding, String> m = new EnumMap<>(ContentCoding.class);
+        m.put(ContentCoding.BROTLI, "org.brotli.dec.BrotliInputStream");
+        m.put(ContentCoding.ZSTD, "com.github.luben.zstd.ZstdInputStream");
+        m.put(ContentCoding.XZ, "org.tukaani.xz.XZInputStream");
+        m.put(ContentCoding.LZMA, "org.tukaani.xz.XZInputStream");
+        REQUIRED_CLASS_NAME = Collections.unmodifiableMap(m);
+    }
+
+    private final String encoding;
+
+    CommonsCompressDecoderFactory(final String encoding) {
+        this.encoding = encoding.toLowerCase(Locale.ROOT);
+    }
+
+    @Override
+    public String getContentEncoding() {
+        return encoding;
+    }
+
+    @Override
+    public InputStream create(final InputStream source) throws IOException {
+        try {
+            return new CompressorStreamFactory()
+                    .createCompressorInputStream(encoding, source);
+        } catch (final CompressorException | LinkageError ex) {
+            throw new IOException(
+                    "Unable to decode Content-Encoding '" + encoding + '\'', ex);
+        }
+    }
+
+
+    static boolean runtimeAvailable(final String token) {
+        final ContentCoding coding = ContentCoding.fromToken(token);
+        if (coding == null) {
+            return true;
+        }
+        final String helper = REQUIRED_CLASS_NAME.get(coding);
+        if (helper == null) {
+            // no extra JAR needed
+            return true;
+        }
+        try {
+            Class.forName(helper, false,
+                    CommonsCompressDecoderFactory.class.getClassLoader());
+            return true;
+        } catch (final ClassNotFoundException | LinkageError ex) {
+            return false;
+        }
+    }
+}

httpclient5/src/main/java/org/apache/hc/client5/http/entity/compress/ContentCoding.java

@@ -0,0 +1,136 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.hc.client5.http.entity.compress;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * Enumeration of the canonical IANA content-coding tokens supported by HttpClient for
+ * HTTP request and response bodies.
+ * <p>
+ * Each constant corresponds to the standard token used in the {@code Content-Encoding}
+ * and {@code Accept-Encoding} headers.  Some codings (e.g. Brotli, Zstandard, XZ/LZMA)
+ * may require additional helper libraries at runtime.
+ *
+ * @since 5.6
+ */
+public enum ContentCoding {
+
+    /**
+     * GZIP compression format.
+     */
+    GZIP("gzip"),
+    /**
+     * "deflate" compression format (zlib or raw).
+     */
+    DEFLATE("deflate"),
+    /**
+     * Legacy alias for GZIP.
+     */
+    X_GZIP("x-gzip"),
+
+    // Optional codecs requiring Commons-Compress or native helpers
+    /**
+     * Brotli compression format.
+     */
+    BROTLI("br"),
+    /**
+     * Zstandard compression format.
+     */
+    ZSTD("zstd"),
+    /**
+     * XZ compression format.
+     */
+    XZ("xz"),
+    /**
+     * LZMA compression format.
+     */
+    LZMA("lzma"),
+    /**
+     * Framed LZ4 compression format.
+     */
+    LZ4_FRAMED("lz4-framed"),
+    /**
+     * Block LZ4 compression format.
+     */
+    LZ4_BLOCK("lz4-block"),
+    /**
+     * BZIP2 compression format.
+     */
+    BZIP2("bzip2"),
+    /**
+     * Pack200 compression format.
+     */
+    PACK200("pack200"),
+    /**
+     * Deflate64 compression format.
+     */
+    DEFLATE64("deflate64");
+
+    private static final Map<String, ContentCoding> TOKEN_LOOKUP;
+    static {
+        final Map<String, ContentCoding> map = new HashMap<>(values().length, 1f);
+        for (final ContentCoding contentCoding : values()) {
+            map.put(contentCoding.token, contentCoding);
+        }
+        TOKEN_LOOKUP = Collections.unmodifiableMap(map);
+    }
+
+    private final String token;
+
+    ContentCoding(final String token) {
+        this.token = token;
+    }
+
+    /**
+     * Returns the standard IANA token string for this content-coding.
+     *
+     * @return the lowercase token used in HTTP headers
+     */
+    public String token() {
+        return token;
+    }
+
+    /**
+     * Lookup an enum by its token (case‐insensitive), or {@code null} if none matches.
+     * <p>
+     * This method is backed by a static, pre‐populated map so the lookup is O(1)
+     * instead of O(n).</p>
+     *
+     * @param token the content‐coding token to look up
+     * @return the matching enum constant, or {@code null} if none
+     */
+    public static ContentCoding fromToken(final String token) {
+        return TOKEN_LOOKUP.get(
+                token == null ? null : token.toLowerCase(Locale.ROOT)
+        );
+    }
+}