Function compatible mapper (helidon-io#1637)

danielkec · web-flow · commit b1de9621fb09 · 2020-04-17T09:22:54.000+02:00
Signed-off-by: Daniel Kec &lt;daniel.kec@oracle.com&gt;
diff --git a/common/mapper/src/main/java/io/helidon/common/mapper/Mapper.java b/common/mapper/src/main/java/io/helidon/common/mapper/Mapper.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
  */
 package io.helidon.common.mapper;
 
+import java.util.function.Function;
+
 /**
  * A generic and general approach to mapping two types.
  * A mapper is unidirectional - from {@code SOURCE} to {@code TARGET}.
@@ -23,12 +25,17 @@
  * @param <TARGET> type of the supported target
  */
 @FunctionalInterface
-public interface Mapper<SOURCE, TARGET> {
+public interface Mapper<SOURCE, TARGET> extends Function<SOURCE, TARGET> {
     /**
      * Map an instance of source type to an instance of target type.
      *
      * @param source object to map
      * @return result of the mapping
      */
     TARGET map(SOURCE source);
+
+    @Override
+    default TARGET apply(SOURCE source){
+        return map(source);
+    }
 }
diff --git a/media/common/src/main/java/io/helidon/media/common/ByteChannelBodyWriter.java b/media/common/src/main/java/io/helidon/media/common/ByteChannelBodyWriter.java
@@ -53,7 +53,7 @@ public Publisher<DataChunk> write(Single<ReadableByteChannel> content, GenericTy
             MessageBodyWriterContext context) {
 
         context.contentType(MediaType.APPLICATION_OCTET_STREAM);
-        return content.flatMap(mapper::map);
+        return content.flatMap(mapper);
     }
 
     /**
diff --git a/media/common/src/main/java/io/helidon/media/common/CharSequenceBodyWriter.java b/media/common/src/main/java/io/helidon/media/common/CharSequenceBodyWriter.java
@@ -45,7 +45,7 @@ public Publisher<DataChunk> write(Single<CharSequence> content, GenericType<? ex
             MessageBodyWriterContext context) {
 
         context.contentType(MediaType.TEXT_PLAIN);
-        return content.flatMap(new CharSequenceToChunks(context.charset())::map);
+        return content.flatMap(new CharSequenceToChunks(context.charset()));
     }
 
     /**
diff --git a/media/common/src/main/java/io/helidon/media/common/ContentReaders.java b/media/common/src/main/java/io/helidon/media/common/ContentReaders.java
@@ -63,7 +63,7 @@ public static Single<byte[]> readBytes(Publisher<DataChunk> chunks) {
      * @return Single
      */
     public static Single<String> readString(Publisher<DataChunk> chunks, Charset charset) {
-        return readBytes(chunks).map(new BytesToString(charset)::map);
+        return readBytes(chunks).map(new BytesToString(charset));
     }
 
     /**
@@ -75,7 +75,7 @@ public static Single<String> readString(Publisher<DataChunk> chunks, Charset cha
      */
     public static Single<String> readURLEncodedString(Publisher<DataChunk> chunks,
             Charset charset) {
-        return readString(chunks, charset).map(new StringToDecodedString(charset)::map);
+        return readString(chunks, charset).map(new StringToDecodedString(charset));
     }
 
     /**
diff --git a/media/common/src/main/java/io/helidon/media/common/FileBodyWriter.java b/media/common/src/main/java/io/helidon/media/common/FileBodyWriter.java
@@ -50,7 +50,7 @@ public boolean accept(GenericType<?> type, MessageBodyWriterContext context) {
 
     @Override
     public Publisher<DataChunk> write(Single<File> content, GenericType<? extends File> type, MessageBodyWriterContext context) {
-        return content.flatMap(new FileToChunks(DEFAULT_RETRY_SCHEMA, context)::map);
+        return content.flatMap(new FileToChunks(DEFAULT_RETRY_SCHEMA, context));
     }
 
     /**
diff --git a/media/common/src/main/java/io/helidon/media/common/MessageBodyWriterContext.java b/media/common/src/main/java/io/helidon/media/common/MessageBodyWriterContext.java
@@ -260,7 +260,7 @@ public <T> Publisher<DataChunk> marshall(Single<T> content, GenericType<T> type,
                 return applyFilters(Multi.<DataChunk>empty());
             }
             if (byte[].class.equals(type.rawType())) {
-                return applyFilters(((Single<byte[]>) content).flatMap(BYTES_MAPPER::map));
+                return applyFilters(((Single<byte[]>) content).flatMap(BYTES_MAPPER));
             }
             MessageBodyWriter<T> writer;
             if (fallback != null) {
diff --git a/media/common/src/main/java/io/helidon/media/common/PathBodyWriter.java b/media/common/src/main/java/io/helidon/media/common/PathBodyWriter.java
@@ -49,7 +49,7 @@ public boolean accept(GenericType<?> type, MessageBodyWriterContext context) {
 
     @Override
     public Publisher<DataChunk> write(Single<Path> content, GenericType<? extends Path> type, MessageBodyWriterContext context) {
-        return content.flatMap(new PathToChunks(DEFAULT_RETRY_SCHEMA, context)::map);
+        return content.flatMap(new PathToChunks(DEFAULT_RETRY_SCHEMA, context));
     }
 
     /**
diff --git a/media/common/src/main/java/io/helidon/media/common/ThrowableBodyWriter.java b/media/common/src/main/java/io/helidon/media/common/ThrowableBodyWriter.java
@@ -49,7 +49,7 @@ public Publisher<DataChunk> write(Single<Throwable> content,
                                       GenericType<? extends Throwable> type,
                                       MessageBodyWriterContext context) {
         context.contentType(MediaType.TEXT_PLAIN);
-        return content.flatMap(new ThrowableToChunks(context.charset())::map);
+        return content.flatMap(new ThrowableToChunks(context.charset()));
     }
 
     /**
diff --git a/media/jackson/common/src/main/java/io/helidon/media/jackson/common/JacksonBodyReader.java b/media/jackson/common/src/main/java/io/helidon/media/jackson/common/JacksonBodyReader.java
@@ -52,7 +52,7 @@ public boolean accept(GenericType<?> type, MessageBodyReaderContext context) {
     public <U extends Object> Single<U> read(Publisher<DataChunk> publisher,
             GenericType<U> type, MessageBodyReaderContext context) {
 
-        return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, objectMapper)::map);
+        return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, objectMapper));
     }
 
     /**
diff --git a/media/jackson/common/src/main/java/io/helidon/media/jackson/common/JacksonBodyWriter.java b/media/jackson/common/src/main/java/io/helidon/media/jackson/common/JacksonBodyWriter.java
@@ -56,7 +56,7 @@ public Publisher<DataChunk> write(Single<Object> content, GenericType<? extends
 
         MediaType contentType = context.findAccepted(MediaType.JSON_PREDICATE, MediaType.APPLICATION_JSON);
         context.contentType(contentType);
-        return content.flatMap(new ObjectToChunks(objectMapper, context.charset())::map);
+        return content.flatMap(new ObjectToChunks(objectMapper, context.charset()));
     }
 
     /**
diff --git a/media/jsonb/common/src/main/java/io/helidon/media/jsonb/common/JsonbBodyReader.java b/media/jsonb/common/src/main/java/io/helidon/media/jsonb/common/JsonbBodyReader.java
@@ -53,7 +53,7 @@ public boolean accept(GenericType<?> type, MessageBodyReaderContext context) {
     public <U extends Object> Single<U> read(Publisher<DataChunk> publisher,
             GenericType<U> type, MessageBodyReaderContext context) {
 
-        return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, jsonb)::map);
+        return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, jsonb));
     }
 
     /**
diff --git a/media/jsonb/common/src/main/java/io/helidon/media/jsonb/common/JsonbBodyWriter.java b/media/jsonb/common/src/main/java/io/helidon/media/jsonb/common/JsonbBodyWriter.java
@@ -57,7 +57,7 @@ public Publisher<DataChunk> write(Single<Object> content,  GenericType<? extends
 
         MediaType contentType = context.findAccepted(MediaType.JSON_PREDICATE, MediaType.APPLICATION_JSON);
         context.contentType(contentType);
-        return content.flatMap(new ObjectToChunks(jsonb, context.charset())::map);
+        return content.flatMap(new ObjectToChunks(jsonb, context.charset()));
     }
 
     /**
diff --git a/media/jsonp/common/src/main/java/io/helidon/media/jsonp/common/JsonpBodyReader.java b/media/jsonp/common/src/main/java/io/helidon/media/jsonp/common/JsonpBodyReader.java
@@ -56,7 +56,7 @@ public <U extends JsonStructure> Single<U> read(Publisher<DataChunk> publisher,
             MessageBodyReaderContext context) {
 
         return ContentReaders.readBytes(publisher)
-                .map(new BytesToJsonStructure<>(jsonFactory, type, context.charset())::map);
+                .map(new BytesToJsonStructure<>(jsonFactory, type, context.charset()));
     }
 
     private static final class BytesToJsonStructure<T extends JsonStructure> implements Mapper<byte[], T> {
diff --git a/media/jsonp/common/src/main/java/io/helidon/media/jsonp/common/JsonpBodyWriter.java b/media/jsonp/common/src/main/java/io/helidon/media/jsonp/common/JsonpBodyWriter.java
@@ -54,7 +54,7 @@ public Publisher<DataChunk> write(Single<JsonStructure> content, GenericType<? e
 
         MediaType contentType = context.findAccepted(MediaType.JSON_PREDICATE, MediaType.APPLICATION_JSON);
         context.contentType(contentType);
-        return content.flatMap(new JsonStructureToChunks(jsonWriterFactory, context.charset())::map);
+        return content.flatMap(new JsonStructureToChunks(jsonWriterFactory, context.charset()));
     }
 
     static final class JsonStructureToChunks implements Mapper<JsonStructure, Publisher<DataChunk>> {

Original file line number	Diff line number	Diff line change
`@@ -53,7 +53,7 @@ public Publisher<DataChunk> write(Single<ReadableByteChannel> content, GenericTy`
`53`	`53`	`MessageBodyWriterContext context) {`
`54`	`54`
`55`	`55`	`context.contentType(MediaType.APPLICATION_OCTET_STREAM);`
`56`		`- return content.flatMap(mapper::map);`
	`56`	`+ return content.flatMap(mapper);`
`57`	`57`	`}`
`58`	`58`
`59`	`59`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ public Publisher<DataChunk> write(Single<CharSequence> content, GenericType<? ex`
`45`	`45`	`MessageBodyWriterContext context) {`
`46`	`46`
`47`	`47`	`context.contentType(MediaType.TEXT_PLAIN);`
`48`		`- return content.flatMap(new CharSequenceToChunks(context.charset())::map);`
	`48`	`+ return content.flatMap(new CharSequenceToChunks(context.charset()));`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -50,7 +50,7 @@ public boolean accept(GenericType<?> type, MessageBodyWriterContext context) {`
`50`	`50`
`51`	`51`	`@Override`
`52`	`52`	`public Publisher<DataChunk> write(Single<File> content, GenericType<? extends File> type, MessageBodyWriterContext context) {`
`53`		`- return content.flatMap(new FileToChunks(DEFAULT_RETRY_SCHEMA, context)::map);`
	`53`	`+ return content.flatMap(new FileToChunks(DEFAULT_RETRY_SCHEMA, context));`
`54`	`54`	`}`
`55`	`55`
`56`	`56`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -260,7 +260,7 @@ public <T> Publisher<DataChunk> marshall(Single<T> content, GenericType<T> type,`
`260`	`260`	`return applyFilters(Multi.<DataChunk>empty());`
`261`	`261`	`}`
`262`	`262`	`if (byte[].class.equals(type.rawType())) {`
`263`		`- return applyFilters(((Single<byte[]>) content).flatMap(BYTES_MAPPER::map));`
	`263`	`+ return applyFilters(((Single<byte[]>) content).flatMap(BYTES_MAPPER));`
`264`	`264`	`}`
`265`	`265`	`MessageBodyWriter<T> writer;`
`266`	`266`	`if (fallback != null) {`
Original file line number	Diff line number	Diff line change
`@@ -49,7 +49,7 @@ public boolean accept(GenericType<?> type, MessageBodyWriterContext context) {`
`49`	`49`
`50`	`50`	`@Override`
`51`	`51`	`public Publisher<DataChunk> write(Single<Path> content, GenericType<? extends Path> type, MessageBodyWriterContext context) {`
`52`		`- return content.flatMap(new PathToChunks(DEFAULT_RETRY_SCHEMA, context)::map);`
	`52`	`+ return content.flatMap(new PathToChunks(DEFAULT_RETRY_SCHEMA, context));`
`53`	`53`	`}`
`54`	`54`
`55`	`55`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -49,7 +49,7 @@ public Publisher<DataChunk> write(Single<Throwable> content,`
`49`	`49`	`GenericType<? extends Throwable> type,`
`50`	`50`	`MessageBodyWriterContext context) {`
`51`	`51`	`context.contentType(MediaType.TEXT_PLAIN);`
`52`		`- return content.flatMap(new ThrowableToChunks(context.charset())::map);`
	`52`	`+ return content.flatMap(new ThrowableToChunks(context.charset()));`
`53`	`53`	`}`
`54`	`54`
`55`	`55`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -52,7 +52,7 @@ public boolean accept(GenericType<?> type, MessageBodyReaderContext context) {`
`52`	`52`	`public <U extends Object> Single<U> read(Publisher<DataChunk> publisher,`
`53`	`53`	`GenericType<U> type, MessageBodyReaderContext context) {`
`54`	`54`
`55`		`- return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, objectMapper)::map);`
	`55`	`+ return ContentReaders.readBytes(publisher).map(new BytesToObject<>(type, objectMapper));`
`56`	`56`	`}`
`57`	`57`
`58`	`58`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -56,7 +56,7 @@ public Publisher<DataChunk> write(Single<Object> content, GenericType<? extends`
`56`	`56`
`57`	`57`	`MediaType contentType = context.findAccepted(MediaType.JSON_PREDICATE, MediaType.APPLICATION_JSON);`
`58`	`58`	`context.contentType(contentType);`
`59`		`- return content.flatMap(new ObjectToChunks(objectMapper, context.charset())::map);`
	`59`	`+ return content.flatMap(new ObjectToChunks(objectMapper, context.charset()));`
`60`	`60`	`}`
`61`	`61`
`62`	`62`	`/**`