Javadoc singleton versus default instances

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

@@ -58,6 +58,9 @@ import org.apache.hc.core5.util.Args;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 public class HttpCacheEntryFactory {
 
+    /**
+     * Default instance of {@link HttpCacheEntryFactory}.
+     */
     public static final HttpCacheEntryFactory INSTANCE = new HttpCacheEntryFactory();
 
     private static HeaderGroup headers(final Iterator<Header> it) {

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

@@ -58,6 +58,9 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public final class ByteArrayCacheEntrySerializer implements HttpCacheEntrySerializer<byte[]> {
 
+    /**
+     * Default instance of {@link ByteArrayCacheEntrySerializer}.
+     */
     public static final ByteArrayCacheEntrySerializer INSTANCE = new ByteArrayCacheEntrySerializer();
 
     @Override

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

@@ -47,6 +47,9 @@ import org.apache.hc.core5.util.CharArrayBuffer;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class CacheControlHeaderGenerator {
 
+    /**
+     * Default instance of {@link CacheControlHeaderGenerator}.
+     */
     public static final CacheControlHeaderGenerator INSTANCE = new CacheControlHeaderGenerator();
 
     public List<NameValuePair> convert(final RequestCacheControl cacheControl) {

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

@@ -70,6 +70,9 @@ import org.apache.hc.core5.util.TextUtils;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class CacheKeyGenerator implements Resolver<URI, String> {
 
+    /**
+     * Default instance of {@link CacheKeyGenerator}.
+     */
     public static final CacheKeyGenerator INSTANCE = new CacheKeyGenerator();
 
     @Override

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

@@ -41,6 +41,9 @@ import org.apache.hc.core5.util.Args;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class HeapResourceFactory implements ResourceFactory {
 
+    /**
+     * Default instance of {@link HeapResourceFactory}.
+     */
     public static final HeapResourceFactory INSTANCE = new HeapResourceFactory();
 
     @Override

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

@@ -91,7 +91,7 @@ public class HttpByteArrayCacheEntrySerializer implements HttpCacheEntrySerializ
     static final String HC_VARIANT = "HC-Variant";
 
     /**
-     * Singleton instance of this class.
+     * Default instance of {@link HttpByteArrayCacheEntrySerializer}.
      */
     public static final HttpByteArrayCacheEntrySerializer INSTANCE = new HttpByteArrayCacheEntrySerializer();
 

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

@@ -41,6 +41,9 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class NoopCacheEntrySerializer implements HttpCacheEntrySerializer<HttpCacheStorageEntry> {
 
+    /**
+     * Default instance of {@link NoopCacheEntrySerializer}.
+     */
     public static final NoopCacheEntrySerializer INSTANCE = new NoopCacheEntrySerializer();
 
     @Override

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

@@ -45,6 +45,9 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 @Contract(threading = ThreadingBehavior.IMMUTABLE)
 class ResponseViaCache implements HttpResponseInterceptor {
 
+    /**
+     * Default instance of {@link ResponseViaCache}.
+     */
     public static final ResponseViaCache INSTANCE = new ResponseViaCache();
 
     @Override

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

@@ -44,6 +44,9 @@ import org.slf4j.LoggerFactory;
  */
 public final class SHA256KeyHashingScheme implements KeyHashingScheme {
 
+    /**
+     * Default instance of {@link SHA256KeyHashingScheme}.
+     */
     public static final SHA256KeyHashingScheme INSTANCE = new SHA256KeyHashingScheme();
 
     private static final Logger LOG = LoggerFactory.getLogger(SHA256KeyHashingScheme.class);

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

@@ -39,6 +39,9 @@ import org.apache.hc.core5.util.TimeValue;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class ImmediateSchedulingStrategy implements SchedulingStrategy {
 
+    /**
+     * Default instance of {@link ImmediateSchedulingStrategy}.
+     */
     public final static ImmediateSchedulingStrategy INSTANCE = new ImmediateSchedulingStrategy();
 
     @Override

httpclient5/src/main/java/org/apache/hc/client5/http/SystemDefaultDnsResolver.java

@@ -36,6 +36,9 @@ import java.net.UnknownHostException;
  */
 public class SystemDefaultDnsResolver implements DnsResolver {
 
+    /**
+     * Default instance of {@link SystemDefaultDnsResolver}.
+     */
     public static final SystemDefaultDnsResolver INSTANCE = new SystemDefaultDnsResolver();
 
     @Override

httpclient5/src/main/java/org/apache/hc/client5/http/cookie/CookieIdentityComparator.java

@@ -46,7 +46,7 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 public class CookieIdentityComparator implements Serializable, Comparator<Cookie> {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link CookieIdentityComparator}.
      *
      * @since 5.2
      */

httpclient5/src/main/java/org/apache/hc/client5/http/cookie/CookiePathComparator.java

@@ -51,6 +51,9 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class CookiePathComparator implements Serializable, Comparator<Cookie> {
 
+    /**
+     * Default instance of {@link CookiePathComparator}.
+     */
     public static final CookiePathComparator INSTANCE = new CookiePathComparator();
 
     private static final long serialVersionUID = 7523645369616405818L;

httpclient5/src/main/java/org/apache/hc/client5/http/cookie/CookiePriorityComparator.java

@@ -43,6 +43,9 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class CookiePriorityComparator implements Comparator<Cookie> {
 
+    /**
+     * Default instance of {@link CookiePriorityComparator}.
+     */
     public static final CookiePriorityComparator INSTANCE = new CookiePriorityComparator();
 
     private int getPathLength(final Cookie cookie) {

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

@@ -41,6 +41,9 @@ import org.brotli.dec.BrotliInputStream;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class BrotliInputStreamFactory implements InputStreamFactory {
 
+    /**
+     * Default instance of {@link BrotliInputStreamFactory}.
+     */
     private static final BrotliInputStreamFactory INSTANCE = new BrotliInputStreamFactory();
 
     public static BrotliInputStreamFactory getInstance() {

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

@@ -42,7 +42,7 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 public class DeflateInputStreamFactory implements InputStreamFactory {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link DeflateInputStreamFactory}.
      */
     private static final DeflateInputStreamFactory INSTANCE = new DeflateInputStreamFactory();
 

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

@@ -43,7 +43,7 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 public class GZIPInputStreamFactory implements InputStreamFactory {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link GZIPInputStreamFactory}.
      */
     private static final GZIPInputStreamFactory INSTANCE = new GZIPInputStreamFactory();
 

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

@@ -61,6 +61,9 @@ public class DefaultAuthenticationStrategy implements AuthenticationStrategy {
 
     private static final Logger LOG = LoggerFactory.getLogger(DefaultAuthenticationStrategy.class);
 
+    /**
+     * Default instance of {@link DefaultAuthenticationStrategy}.
+     */
     public static final DefaultAuthenticationStrategy INSTANCE = new DefaultAuthenticationStrategy();
 
     private static final List<String> DEFAULT_SCHEME_PRIORITY =

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

@@ -44,6 +44,9 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultClientConnectionReuseStrategy extends DefaultConnectionReuseStrategy {
 
+    /**
+     * Default instance of {@link DefaultClientConnectionReuseStrategy}.
+     */
     public static final DefaultClientConnectionReuseStrategy INSTANCE = new DefaultClientConnectionReuseStrategy();
 
     @Override

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

@@ -54,6 +54,9 @@ import org.apache.hc.core5.util.TimeValue;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultConnectionKeepAliveStrategy implements ConnectionKeepAliveStrategy {
 
+    /**
+     * Default instance of {@link DefaultConnectionKeepAliveStrategy}.
+     */
     public static final DefaultConnectionKeepAliveStrategy INSTANCE = new DefaultConnectionKeepAliveStrategy();
 
     @Override

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

@@ -64,6 +64,9 @@ import org.apache.hc.core5.util.TimeValue;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultHttpRequestRetryStrategy implements HttpRequestRetryStrategy {
 
+    /**
+     * Default instance of {@link DefaultHttpRequestRetryStrategy}.
+     */
     public static final DefaultHttpRequestRetryStrategy INSTANCE = new DefaultHttpRequestRetryStrategy();
 
     /**

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

@@ -54,6 +54,9 @@ import org.apache.hc.core5.util.Args;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultRedirectStrategy implements RedirectStrategy {
 
+    /**
+     * Default instance of {@link DefaultRedirectStrategy}.
+     */
     public static final DefaultRedirectStrategy INSTANCE = new DefaultRedirectStrategy();
 
     @Override

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

@@ -42,6 +42,9 @@ import org.apache.hc.core5.util.Args;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultSchemePortResolver implements SchemePortResolver {
 
+    /**
+     * Default instance of {@link DefaultSchemePortResolver}.
+     */
     public static final DefaultSchemePortResolver INSTANCE = new DefaultSchemePortResolver();
 
     @Override

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

@@ -59,6 +59,9 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultUserTokenHandler implements UserTokenHandler {
 
+    /**
+     * Default instance of {@link DefaultUserTokenHandler}.
+     */
     public static final DefaultUserTokenHandler INSTANCE = new DefaultUserTokenHandler();
 
     @Override

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

@@ -40,6 +40,9 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class NoopUserTokenHandler implements UserTokenHandler {
 
+    /**
+     * Default instance of {@link NoopUserTokenHandler}.
+     */
     public static final NoopUserTokenHandler INSTANCE = new NoopUserTokenHandler();
 
     @Override

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

@@ -42,6 +42,9 @@ import org.apache.hc.core5.http.message.BasicHttpRequest;
 @Deprecated
 public final class RequestCopier implements MessageCopier<HttpRequest> {
 
+    /**
+     * Default instance of {@link RequestCopier}.
+     */
     public static final RequestCopier INSTANCE = new RequestCopier();
 
     @Override

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

@@ -33,6 +33,9 @@ import org.slf4j.LoggerFactory;
 
 class LoggingExceptionCallback implements Callback<Exception> {
 
+    /**
+     * Singleton instance of LoggingExceptionCallback.
+     */
     static final LoggingExceptionCallback INSTANCE = new LoggingExceptionCallback();
 
     private static final Logger LOG = LoggerFactory.getLogger("org.apache.hc.client5.http.impl.async");

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

@@ -34,6 +34,9 @@ import org.slf4j.LoggerFactory;
 
 final class LoggingIOSessionDecorator implements Decorator<IOSession> {
 
+    /**
+     * Singleton instance of LoggingIOSessionDecorator.
+     */
     public final static LoggingIOSessionDecorator INSTANCE = new LoggingIOSessionDecorator();
 
     private static final Logger WIRE_LOG = LoggerFactory.getLogger("org.apache.hc.client5.http.wire");

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

@@ -46,6 +46,9 @@ import org.apache.hc.core5.util.Tokenizer;
  */
 public class AuthChallengeParser {
 
+    /**
+     * Default instance of {@link AuthChallengeParser}.
+     */
     public static final AuthChallengeParser INSTANCE = new AuthChallengeParser();
 
     private final Tokenizer tokenParser = Tokenizer.INSTANCE;

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

@@ -46,7 +46,7 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 public class BasicSchemeFactory implements AuthSchemeFactory {
 
     /**
-     * Singleton instance with a null Charset.
+     * Default instance of {@link BasicSchemeFactory with a null Charset}.
      */
     public static final BasicSchemeFactory INSTANCE = new BasicSchemeFactory();
 

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

@@ -42,6 +42,9 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class BearerSchemeFactory implements AuthSchemeFactory {
 
+    /**
+     * Default instance of {@link BearerSchemeFactory}.
+     */
     public static final BearerSchemeFactory INSTANCE = new BearerSchemeFactory();
 
     public BearerSchemeFactory() {

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

@@ -46,11 +46,10 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 public class DigestSchemeFactory implements AuthSchemeFactory {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link DigestSchemeFactory}.
      */
     public static final DigestSchemeFactory INSTANCE = new DigestSchemeFactory();
 
-
     /**
      * @param charset the {@link Charset} set to be used for encoding credentials. This parameter is ignored as UTF-8 is always used.
      * @deprecated This constructor is deprecated to enforce the use of {@link StandardCharsets#UTF_8} encoding

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

@@ -50,7 +50,7 @@ import org.apache.hc.core5.http.protocol.HttpContext;
 public class NTLMSchemeFactory implements AuthSchemeFactory {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link NTLMSchemeFactory}.
      */
     public static final NTLMSchemeFactory INSTANCE = new NTLMSchemeFactory();
 

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

@@ -42,6 +42,9 @@ import org.apache.hc.core5.http.message.BasicClassicHttpRequest;
 @Deprecated
 public final class ClassicRequestCopier implements org.apache.hc.client5.http.impl.MessageCopier<ClassicHttpRequest> {
 
+    /**
+     * Default instance of {@link ClassicRequestCopier}.
+     */
     public static final ClassicRequestCopier INSTANCE = new ClassicRequestCopier();
 
     @Override

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

@@ -50,7 +50,7 @@ public class BasicDomainHandler implements CommonCookieAttributeHandler {
 
 
     /**
-     * Singleton instance.
+     * Default instance of {@link BasicDomainHandler}.
      *
      * @since 5.2
      */

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

@@ -44,7 +44,7 @@ import org.apache.hc.core5.util.Args;
 public class BasicHttpOnlyHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link BasicHttpOnlyHandler}.
      *
      * @since 5.2
      */

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

@@ -45,7 +45,7 @@ import org.apache.hc.core5.util.Args;
 public class BasicMaxAgeHandler extends AbstractCookieAttributeHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link BasicMaxAgeHandler}.
      *
      * @since 5.2
      */

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

@@ -45,7 +45,7 @@ import org.apache.hc.core5.util.TextUtils;
 public class BasicPathHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link BasicPathHandler}.
      *
      * @since 5.2
      */

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

@@ -44,7 +44,7 @@ import org.apache.hc.core5.util.Args;
 public class BasicSecureHandler extends AbstractCookieAttributeHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance BasicSecureHandler.
      *
      * @since 5.2
      */

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

@@ -46,7 +46,7 @@ import org.apache.hc.core5.http.Header;
 public class IgnoreSpecSpec extends CookieSpecBase {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link IgnoreSpecSpec}.
      *
      * @since 5.2
      */

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

@@ -57,7 +57,7 @@ import org.apache.hc.core5.util.Tokenizer;
 public class LaxExpiresHandler extends AbstractCookieAttributeHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link LaxExpiresHandler}.
      *
      * @since 5.2
      */

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

@@ -49,7 +49,7 @@ import org.apache.hc.core5.util.TextUtils;
 public class LaxMaxAgeHandler extends AbstractCookieAttributeHandler implements CommonCookieAttributeHandler {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link LaxMaxAgeHandler}.
      *
      * @since 5.2
      */

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

@@ -46,6 +46,9 @@ import org.apache.hc.core5.http.message.LineParser;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class DefaultHttpResponseParserFactory implements HttpMessageParserFactory<ClassicHttpResponse> {
 
+    /**
+     * Default instance DefaultHttpResponseParserFactory.
+     */
     public static final DefaultHttpResponseParserFactory INSTANCE = new DefaultHttpResponseParserFactory();
 
     private final Http1Config h1Config;

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

@@ -60,6 +60,9 @@ public class ManagedHttpClientConnectionFactory implements HttpConnectionFactory
 
     private static final AtomicLong COUNTER = new AtomicLong();
 
+    /**
+     * Default instance of {@link ManagedHttpClientConnectionFactory}.
+     */
     public static final ManagedHttpClientConnectionFactory INSTANCE = new ManagedHttpClientConnectionFactory();
 
     private final Http1Config h1Config;

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

@@ -42,7 +42,7 @@ import org.apache.hc.core5.util.Args;
 public class BasicRouteDirector implements HttpRouteDirector {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link BasicRouteDirector}.
      *
      * @since 5.2
      */

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

@@ -67,7 +67,7 @@ import org.slf4j.LoggerFactory;
 public class RequestAddCookies implements HttpRequestInterceptor {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link RequestAddCookies}.
      *
      * @since 5.2
      */

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

@@ -50,7 +50,7 @@ import org.apache.hc.core5.util.Args;
 public class RequestDefaultHeaders implements HttpRequestInterceptor {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link RequestDefaultHeaders}.
      *
      * @since 5.2
      */

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

@@ -72,7 +72,7 @@ import org.apache.hc.core5.util.Args;
 public class RequestIfRange implements HttpRequestInterceptor {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link RequestIfRange}.
      *
      * @since 5.4
      */

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

@@ -101,7 +101,7 @@ import org.apache.hc.core5.util.Args;
 public class RequestValidateTrace implements HttpRequestInterceptor {
 
     /**
-     * Singleton instance of {@link RequestValidateTrace}.
+     * Default instance of {@link RequestValidateTrace}.
      */
     public static final HttpRequestInterceptor INSTANCE = new RequestValidateTrace();
 

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

@@ -59,7 +59,7 @@ import org.slf4j.LoggerFactory;
 public class ResponseProcessCookies implements HttpResponseInterceptor {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link ResponseProcessCookies}.
      *
      * @since 5.2
      */

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

@@ -45,7 +45,7 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 public final class PublicSuffixListParser {
 
     /**
-     * Singleton instance.
+     * Default instance of {@link PublicSuffixListParser}.
      *
      * @since 5.2
      */

httpclient5/src/main/java/org/apache/hc/client5/http/socket/PlainConnectionSocketFactory.java

@@ -56,6 +56,9 @@ import org.apache.hc.core5.util.TimeValue;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class PlainConnectionSocketFactory implements ConnectionSocketFactory {
 
+    /**
+     * Default instance of {@link PlainConnectionSocketFactory}.
+     */
     public static final PlainConnectionSocketFactory INSTANCE = new PlainConnectionSocketFactory();
 
     public static PlainConnectionSocketFactory getSocketFactory() {

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

@@ -37,6 +37,9 @@ import org.apache.hc.core5.util.Tokenizer;
 
 final class DistinguishedNameParser {
 
+    /**
+     * Default instance of {@link DistinguishedNameParser}.
+     */
     public final static DistinguishedNameParser INSTANCE = new DistinguishedNameParser();
 
     private static final Tokenizer.Delimiter EQUAL_OR_COMMA_OR_PLUS = Tokenizer.delimiters('=', ',', '+');

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

@@ -42,6 +42,9 @@ import org.apache.hc.core5.annotation.ThreadingBehavior;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class NoopHostnameVerifier implements HostnameVerifier {
 
+    /**
+     * Default instance of {@link NoopHostnameVerifier}.
+     */
     public static final NoopHostnameVerifier INSTANCE = new NoopHostnameVerifier();
 
     @Override

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

@@ -50,6 +50,9 @@ import org.apache.hc.core5.ssl.TrustStrategy;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class TrustAllStrategy implements TrustStrategy {
 
+    /**
+     * Default instance of {@link TrustAllStrategy}.
+     */
     public static final TrustAllStrategy INSTANCE = new TrustAllStrategy();
 
     @Override

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

@@ -52,6 +52,9 @@ import org.apache.hc.core5.ssl.TrustStrategy;
 @Contract(threading = ThreadingBehavior.STATELESS)
 public class TrustSelfSignedStrategy implements TrustStrategy {
 
+    /**
+     * Default instance of {@link TrustSelfSignedStrategy}
+     */
     public static final TrustSelfSignedStrategy INSTANCE = new TrustSelfSignedStrategy();
 
     @Override