minor changes.

Author: arturobernalg

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

@@ -29,7 +29,10 @@
 
 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;
@@ -39,27 +42,37 @@
 import org.apache.hc.core5.annotation.ThreadingBehavior;
 
 /**
- * {@link InputStreamFactory} backed by
- * <a href="https://commons.apache.org/proper/commons-compress/">Apache&nbsp;Commons Compress</a>.
+ * 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>
- * The class is compiled against Commons Compress but lives behind an <i>optional</i>
- * dependency.  At run-time it will only be loaded when the library is present,
- * therefore callers may rely on it without pulling Commons Compress into every
- * downstream build.
- * </p>
- *
- * <h4>Run-time guards</h4>
- * Some encodings (e.g.&nbsp;{@code br}, {@code zstd}, {@code xz/lzma})
- * depend on native helper JARs.  {@link #runtimeAvailable(String)} performs a
- * lightweight {@code Class.forName} probe so we register such codecs only when
- * the helper is on the class-path.
+ * <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) {
@@ -82,37 +95,19 @@ public InputStream create(final InputStream source) throws IOException {
         }
     }
 
-    private enum Probe {
-        BR(ContentCoding.BROTLI.token(), "org.brotli.dec.BrotliInputStream"),
-        ZSTD(ContentCoding.ZSTD.token(), "com.github.luben.zstd.ZstdInputStream"),
-        XZ(ContentCoding.XZ.token(), "org.tukaani.xz.XZInputStream"),
-        LZMA(ContentCoding.LZMA.token(), "org.tukaani.xz.XZInputStream");
 
-        final String enc, probeClass;
-
-        Probe(final String enc, final String probeClass) {
-            this.enc = enc;
-            this.probeClass = probeClass;
-        }
-
-        static String helperFor(final String enc) {
-            for (final Probe p : values()) {
-                if (p.enc.equals(enc)) {
-                    return p.probeClass;
-                }
-            }
-            return null;
+    static boolean runtimeAvailable(final String token) {
+        final ContentCoding coding = ContentCoding.fromToken(token);
+        if (coding == null) {
+            return true;
         }
-    }
-
-    static boolean runtimeAvailable(final String enc) {
-        final String probe = Probe.helperFor(enc.toLowerCase(Locale.ROOT));
-        if (probe == null) {
+        final String helper = REQUIRED_CLASS_NAME.get(coding);
+        if (helper == null) {
+            // no extra JAR needed
             return true;
         }
         try {
-            Class.forName(
-                    probe, false,
+            Class.forName(helper, false,
                     CommonsCompressDecoderFactory.class.getClassLoader());
             return true;
         } catch (final ClassNotFoundException | LinkageError ex) {

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

@@ -27,6 +27,8 @@
 
 package org.apache.hc.client5.http.entity.compress;
 
+import java.util.Locale;
+
 /**
  * Enumeration of the canonical IANA content-coding tokens supported by HttpClient for
  * HTTP request and response bodies.
@@ -104,4 +106,17 @@ public enum ContentCoding {
     public String token() {
         return token;
     }
+
+    /**
+     * Lookup the enum by token (case-insensitive).
+     */
+    public static ContentCoding fromToken(final String token) {
+        final String copyToken = token.toLowerCase(Locale.ROOT);
+        for (final ContentCoding coding : values()) {
+            if (coding.token.equals(copyToken)) {
+                return coding;
+            }
+        }
+        return null;
+    }
 }

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

@@ -130,7 +130,7 @@ private static boolean commonsCompressPresent() {
             Class.forName(
                     CCSF, false, ContentDecoderRegistry.class.getClassLoader());
             return true;
-        } catch (final ClassNotFoundException e) {
+        } catch (final ClassNotFoundException | LinkageError ex) {
             return false;
         }
     }