Reactive Media Common deprecated cleanup. (#6098)

- Remove the following methods in ContentWriters that are deprecated in 3.x:
    - byteArrayWriter
    - charSequenceWriter
    - charBufferWriter
    - byteChannelWriter (updated PathBodyWriter and FileBodyWriter to remove usage)
- Updated ContentWriterTests and ContentReaderTests: consistent test method names (e.g. charSequenceWriter -> writeCharSequence)
- Removed unused private code in MessageBodyWriterContext and MessageBodyReadableContent

Fixes #4364

Author: romain-grecourt

examples/webserver/tutorial/src/main/java/io/helidon/reactive/webserver/examples/tutorial/CommentService.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -187,8 +187,7 @@ Flow.Publisher<DataChunk> publish(List<Comment> comments) {
             String str = comments.stream()
                     .map(Comment::toString)
                     .collect(Collectors.joining("\n"));
-            return ContentWriters.charSequenceWriter(StandardCharsets.UTF_8)
-                    .apply(str + "\n");
+            return ContentWriters.writeCharSequence(str + "\n", StandardCharsets.UTF_8);
         }
 
     }

reactive/media/common/src/main/java/io/helidon/reactive/media/common/ContentReaders.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -81,13 +81,7 @@ public static Single<String> readURLEncodedString(Publisher<DataChunk> chunks,
      * Implementation of {@link Mapper} that converts a {@code byte[]} into
      * a {@link String} using a given {@link Charset}.
      */
-    private static final class BytesToString implements Mapper<byte[], String> {
-
-        private final Charset charset;
-
-        BytesToString(Charset charset) {
-            this.charset = charset;
-        }
+    private record BytesToString(Charset charset) implements Mapper<byte[], String> {
 
         @Override
         public String map(byte[] bytes) {
@@ -98,19 +92,14 @@ public String map(byte[] bytes) {
     /**
      * Mapper that applies URL decoding to a {@code String}.
      */
-    private static final class StringToDecodedString implements Mapper<String, String> {
-
-        private final Charset charset;
-
-        StringToDecodedString(Charset charset) {
-            this.charset = charset;
-        }
+    private record StringToDecodedString(Charset charset) implements Mapper<String, String> {
 
         @Override
         public String map(String s) {
             return URLDecoder.decode(s, charset);
         }
     }
+
     /**
      * Implementation of {@link Collector} that collects chunks into a single
      * {@code byte[]}.

reactive/media/common/src/main/java/io/helidon/reactive/media/common/ContentWriters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,15 +19,9 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.nio.ByteBuffer;
-import java.nio.channels.ReadableByteChannel;
 import java.nio.charset.Charset;
-import java.util.Objects;
-import java.util.concurrent.Flow.Publisher;
-import java.util.function.Function;
 
 import io.helidon.common.http.DataChunk;
-import io.helidon.common.reactive.IoMulti;
-import io.helidon.common.reactive.RetrySchema;
 import io.helidon.common.reactive.Single;
 
 /**
@@ -115,88 +109,4 @@ public static Single<DataChunk> writeStackTrace(Throwable throwable, Charset cha
         }
         return returnValue;
     }
-
-    /**
-     * Returns a writer function for {@code byte[]}.
-     * <p>
-     * The {@code copy} variant is by default registered in
-     * {@code ServerResponse}.
-     *
-     * @param copy a signal if byte array should be copied - set it {@code true}
-     * if {@code byte[]} will be immediately reused.
-     * @return a {@code byte[]} writer
-     *
-     * @deprecated since 2.0.0, use {@link #writeBytes(byte[], boolean)} instead
-     */
-    @Deprecated(since = "2.0.0")
-    public static Function<byte[], Publisher<DataChunk>> byteArrayWriter(boolean copy) {
-        return (bytes) -> writeBytes(bytes, copy);
-    }
-
-    /**
-     * Returns a writer function for {@link CharSequence} using provided
-     * standard {@code charset}.
-     * <p>
-     * An instance is by default registered in {@code ServerResponse} for all
-     * standard charsets.
-     *
-     * @param charset a standard charset to use
-     * @return a {@link String} writer
-     * @throws NullPointerException if parameter {@code charset} is {@code null}
-     * @deprecated since 2.0.0, use {@link #writeCharSequence(CharSequence, Charset)}
-     *  or {@link DefaultMediaSupport#charSequenceWriter()} instead
-     */
-    @Deprecated(since = "2.0.0")
-    public static Function<CharSequence, Publisher<DataChunk>> charSequenceWriter(Charset charset) {
-        return (cs) -> writeCharSequence(cs, charset);
-    }
-
-    /**
-     * Returns a writer function for {@link CharBuffer} using provided standard
-     * {@code charset}.
-     * <p>
-     * An instance is by default registered in {@code ServerResponse} for all
-     * standard charsets.
-     *
-     * @param charset a standard charset to use
-     * @return a {@link String} writer
-     * @throws NullPointerException if parameter {@code charset} is {@code null}
-     * @deprecated since 2.0.0, use {@link #writeCharBuffer(CharBuffer, Charset)} instead
-     */
-    @Deprecated(since = "2.0.0")
-    public static Function<CharBuffer, Publisher<DataChunk>> charBufferWriter(Charset charset) {
-        return (buffer) -> writeCharBuffer(buffer, charset);
-    }
-
-    /**
-     * Returns a writer function for {@link ReadableByteChannel}. Created
-     * publisher use provided {@link RetrySchema} to define delay between
-     * unsuccessful read attempts.
-     *
-     * @param retrySchema a retry schema to use in case when {@code read}
-     * operation reads {@code 0 bytes}
-     * @return a {@link ReadableByteChannel} writer
-     * @deprecated since 2.0.0, use {@link DefaultMediaSupport#byteChannelWriter(RetrySchema)}} instead
-     */
-    @Deprecated(since = "2.0.0")
-    public static Function<ReadableByteChannel, Publisher<DataChunk>> byteChannelWriter(RetrySchema retrySchema) {
-        Objects.requireNonNull(retrySchema);
-
-        return channel -> IoMulti.multiFromByteChannelBuilder(channel)
-                .retrySchema(retrySchema)
-                .build()
-                .map(DataChunk::create);
-    }
-
-    /**
-     * Returns a writer function for {@link ReadableByteChannel}.
-     *
-     * @return a {@link ReadableByteChannel} writer
-     * @deprecated since 2.0.0, use {@link DefaultMediaSupport#byteChannelWriter()}} instead
-     */
-    @Deprecated(since = "2.0.0")
-    public static Function<ReadableByteChannel, Publisher<DataChunk>> byteChannelWriter() {
-        return channel -> IoMulti.multiFromByteChannel(channel).map(DataChunk::create);
-    }
-
 }

reactive/media/common/src/main/java/io/helidon/reactive/media/common/FileBodyWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2020, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@
 import io.helidon.common.http.DataChunk;
 import io.helidon.common.mapper.Mapper;
 import io.helidon.common.media.type.MediaTypes;
+import io.helidon.common.reactive.IoMulti;
 import io.helidon.common.reactive.Single;
 
 /**
@@ -67,13 +68,7 @@ static FileBodyWriter create() {
      * Implementation of {@link Mapper} that converts {@link File} to a
      * publisher of {@link DataChunk}.
      */
-    private static final class FileToChunks implements Mapper<File, Publisher<DataChunk>> {
-
-        private final MessageBodyWriterContext context;
-
-        FileToChunks(MessageBodyWriterContext context) {
-            this.context = context;
-        }
+    private record FileToChunks(MessageBodyWriterContext context) implements Mapper<File, Publisher<DataChunk>> {
 
         @Override
         public Publisher<DataChunk> map(File file) {
@@ -82,9 +77,9 @@ public Publisher<DataChunk> map(File file) {
                 context.contentType(MediaTypes.APPLICATION_OCTET_STREAM);
                 context.contentLength(Files.size(path));
                 FileChannel fc = FileChannel.open(path, StandardOpenOption.READ);
-                return ContentWriters.byteChannelWriter().apply(fc);
+                return IoMulti.multiFromByteChannel(fc).map(DataChunk::create);
             } catch (IOException ex) {
-                return Single.<DataChunk>error(ex);
+                return Single.error(ex);
             }
         }
     }

reactive/media/common/src/main/java/io/helidon/reactive/media/common/MessageBodyReadableContent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2020, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,7 +27,6 @@
 /**
  * Readable {@link MessageBodyContent}.
  */
-@SuppressWarnings("deprecation")
 public final class MessageBodyReadableContent
         implements MessageBodyReaders, MessageBodyFilters, MessageBodyContent, Multi<DataChunk> {
 
@@ -46,16 +45,6 @@ public final class MessageBodyReadableContent
         this.context = context;
     }
 
-    /**
-     * Copy constructor.
-     * @param orig original context to be copied
-     */
-    private MessageBodyReadableContent(MessageBodyReadableContent orig) {
-        Objects.requireNonNull(orig, "orig is null!");
-        this.publisher = orig.publisher;
-        this.context = orig.context;
-    }
-
     /**
      * Get the reader context used to unmarshall data.
      *

reactive/media/common/src/main/java/io/helidon/reactive/media/common/MessageBodyWriterContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2020, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,6 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.Flow.Publisher;
-import java.util.function.Function;
 import java.util.function.Predicate;
 
 import io.helidon.common.GenericType;
@@ -71,11 +70,7 @@ private MessageBodyWriterContext(MessageBodyWriterContext parent,
         super(parent, eventListener);
         Objects.requireNonNull(headers, "headers cannot be null!");
         this.headers = headers;
-        if (acceptedTypes != null) {
-            this.acceptedTypes = acceptedTypes;
-        } else {
-            this.acceptedTypes = List.of();
-        }
+        this.acceptedTypes = Objects.requireNonNullElseGet(acceptedTypes, List::of);
         if (parent != null) {
             this.writers = new MessageBodyOperators<>(parent.writers);
             this.swriters = new MessageBodyOperators<>(parent.swriters);
@@ -98,21 +93,6 @@ private MessageBodyWriterContext(WritableHeaders<?> headers) {
         this.acceptedTypes = List.of();
     }
 
-    /**
-     * Create a new standalone (non parented) context.
-     */
-    private MessageBodyWriterContext() {
-        super(null, null);
-        this.headers = WritableHeaders.create();
-        this.writers = new MessageBodyOperators<>();
-        this.swriters = new MessageBodyOperators<>();
-        this.acceptedTypes = List.of();
-        this.contentTypeCache = Optional.empty();
-        this.contentTypeCached = true;
-        this.charsetCache = DEFAULT_CHARSET;
-        this.charsetCached = true;
-    }
-
     private MessageBodyWriterContext(MessageBodyWriterContext writerContext, WritableHeaders<?> headers) {
         super(writerContext);
         Objects.requireNonNull(headers, "headers cannot be null!");
@@ -378,7 +358,7 @@ public void contentType(HttpMediaType contentType) {
      */
     public void contentType(MediaType mediaType) {
         Objects.requireNonNull(mediaType);
-        headers.setIfAbsent(Http.Header.create(Http.Header.CONTENT_TYPE, false, false, mediaType.fullType()));
+        headers.setIfAbsent(Http.Header.create(Http.Header.CONTENT_TYPE, false, false, mediaType.text()));
     }
 
     /**
@@ -484,67 +464,6 @@ public Charset charset() throws IllegalStateException {
         return charsetCache;
     }
 
-    /**
-     * Message body writer adapter for the old deprecated writer.
-     * @param <T> writer type
-     */
-    private static final class WriterAdapter<T> implements MessageBodyWriter<T> {
-
-        private final Function<T, Publisher<DataChunk>> function;
-        private final Predicate predicate;
-        private final Class<T> type;
-        private final HttpMediaType contentType;
-
-        @SuppressWarnings("unchecked")
-        WriterAdapter(Function<T, Publisher<DataChunk>> function, Predicate<?> predicate, HttpMediaType contentType) {
-            Objects.requireNonNull(function, "function cannot be null!");
-            Objects.requireNonNull(predicate, "predicate cannot be null!");
-            this.function = function;
-            this.predicate = predicate;
-            this.contentType = contentType;
-            this.type = null;
-        }
-
-        @SuppressWarnings("unchecked")
-        WriterAdapter(Function<? extends T, Publisher<DataChunk>> function, Class<T> type, HttpMediaType contentType) {
-            Objects.requireNonNull(function, "function cannot be null!");
-            Objects.requireNonNull(type, "type cannot be null!");
-            this.function = (Function<T, Publisher<DataChunk>>) function;
-            this.type = type;
-            this.contentType = contentType;
-            this.predicate = null;
-        }
-
-        @Override
-        @SuppressWarnings("unchecked")
-        public PredicateResult accept(GenericType<?> type, MessageBodyWriterContext context) {
-            if (this.type != null) {
-                if (!this.type.isAssignableFrom(type.rawType())) {
-                    return PredicateResult.NOT_SUPPORTED;
-                }
-            } else {
-                if (!predicate.test((Object) type.rawType())) {
-                    return PredicateResult.NOT_SUPPORTED;
-                }
-            }
-            HttpMediaType ct = context.contentType().orElse(null);
-            if (!(contentType != null && ct != null && !ct.test(contentType))) {
-                if (contentType != null) {
-                    context.contentType(contentType);
-                }
-                return PredicateResult.SUPPORTED;
-            }
-            return PredicateResult.NOT_SUPPORTED;
-        }
-
-        @Override
-        public Publisher<DataChunk> write(Single<? extends T> single,
-                                          GenericType<? extends T> type,
-                                          MessageBodyWriterContext context) {
-            return single.flatMap(function);
-        }
-    }
-
     /**
      * Implementation of {@link Mapper} to convert {@code byte[]} to
      * a publisher of {@link DataChunk}.