Resource.isFile() and JAF MediaTypeFactory

Issue: SPR-14484

spring-core/src/main/java/org/springframework/core/io/AbstractFileResolvingResource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,20 @@
  */
 public abstract class AbstractFileResolvingResource extends AbstractResource {
 
+	@Override
+	public boolean isFile() {
+		try {
+			URL url = getURL();
+			if (url.getProtocol().startsWith(ResourceUtils.URL_PROTOCOL_VFS)) {
+				return VfsResourceDelegate.getResource(url).isFile();
+			}
+			return ResourceUtils.URL_PROTOCOL_FILE.equals(url.getProtocol());
+		}
+		catch (IOException ex) {
+			return false;
+		}
+	}
+
 	/**
 	 * This implementation returns a File reference for the underlying class path
 	 * resource, provided that it refers to a file in the file system.
@@ -72,7 +86,25 @@ protected File getFileForLastModifiedCheck() throws IOException {
 	}
 
 	/**
-	 * This implementation returns a File reference for the underlying class path
+	 * This implementation returns a File reference for the given URI-identified
+	 * resource, provided that it refers to a file in the file system.
+	 * @since 5.0
+	 * @see #getFile(URI)
+	 */
+	protected boolean isFile(URI uri) {
+		try {
+			if (uri.getScheme().startsWith(ResourceUtils.URL_PROTOCOL_VFS)) {
+				return VfsResourceDelegate.getResource(uri).isFile();
+			}
+			return ResourceUtils.URL_PROTOCOL_FILE.equals(uri.getScheme());
+		}
+		catch (IOException ex) {
+			return false;
+		}
+	}
+
+	/**
+	 * This implementation returns a File reference for the given URI-identified
 	 * resource, provided that it refers to a file in the file system.
 	 * @see org.springframework.util.ResourceUtils#getFile(java.net.URI, String)
 	 */

spring-core/src/main/java/org/springframework/core/io/AbstractResource.java

@@ -81,6 +81,14 @@ public boolean isOpen() {
 		return false;
 	}
 
+	/**
+	 * This implementation always returns {@code false}.
+	 */
+	@Override
+	public boolean isFile() {
+		return false;
+	}
+
 	/**
 	 * This implementation throws a FileNotFoundException, assuming
 	 * that the resource cannot be resolved to a URL.

spring-core/src/main/java/org/springframework/core/io/FileSystemResource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -85,7 +85,6 @@ public final String getPath() {
 		return this.path;
 	}
 
-
 	/**
 	 * This implementation returns whether the underlying file exists.
 	 * @see java.io.File#exists()
@@ -153,6 +152,14 @@ public URI getURI() throws IOException {
 		return this.file.toURI();
 	}
 
+	/**
+	 * This implementation always indicates a file.
+	 */
+	@Override
+	public boolean isFile() {
+		return true;
+	}
+
 	/**
 	 * This implementation returns the underlying File reference.
 	 */

spring-core/src/main/java/org/springframework/core/io/InputStreamSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,7 +49,6 @@ public interface InputStreamSource {
 	 * that each {@code getInputStream()} call returns a fresh stream.
 	 * @return the input stream for the underlying resource (must not be {@code null})
 	 * @throws IOException if the stream could not be opened
-	 * @see org.springframework.mail.javamail.MimeMessageHelper#addAttachment(String, InputStreamSource)
 	 */
 	InputStream getInputStream() throws IOException;
 

spring-core/src/main/java/org/springframework/core/io/PathResource.java

@@ -171,6 +171,14 @@ public URI getURI() throws IOException {
 		return this.path.toUri();
 	}
 
+	/**
+	 * This implementation always indicates a file.
+	 */
+	@Override
+	public boolean isFile() {
+		return true;
+	}
+
 	/**
 	 * This implementation returns the underlying File reference.
 	 */
@@ -180,8 +188,8 @@ public File getFile() throws IOException {
 			return this.path.toFile();
 		}
 		catch (UnsupportedOperationException ex) {
-			// only Paths on the default file system can be converted to a File
-			// do exception translation for cases where conversion is not possible
+			// Only paths on the default file system can be converted to a File:
+			// Do exception translation for cases where conversion is not possible.
 			throw new FileNotFoundException(this.path + " cannot be resolved to " + "absolute file path");
 		}
 	}

spring-core/src/main/java/org/springframework/core/io/Resource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,31 +47,47 @@
 public interface Resource extends InputStreamSource {
 
 	/**
-	 * Return whether this resource actually exists in physical form.
+	 * Determine whether this resource actually exists in physical form.
 	 * <p>This method performs a definitive existence check, whereas the
 	 * existence of a {@code Resource} handle only guarantees a
 	 * valid descriptor handle.
 	 */
 	boolean exists();
 
 	/**
-	 * Return whether the contents of this resource can be read,
-	 * e.g. via {@link #getInputStream()} or {@link #getFile()}.
+	 * Indicate whether the contents of this resource can be read via
+	 * {@link #getInputStream()}.
 	 * <p>Will be {@code true} for typical resource descriptors;
 	 * note that actual content reading may still fail when attempted.
 	 * However, a value of {@code false} is a definitive indication
 	 * that the resource content cannot be read.
 	 * @see #getInputStream()
 	 */
-	boolean isReadable();
+	default boolean isReadable() {
+		return true;
+	}
 
 	/**
-	 * Return whether this resource represents a handle with an open
-	 * stream. If true, the InputStream cannot be read multiple times,
+	 * Indicate whether this resource represents a handle with an open stream.
+	 * If {@code true}, the InputStream cannot be read multiple times,
 	 * and must be read and closed to avoid resource leaks.
 	 * <p>Will be {@code false} for typical resource descriptors.
 	 */
-	boolean isOpen();
+	default boolean isOpen() {
+		return false;
+	}
+
+	/**
+	 * Determine whether this resource represents a file in a file system.
+	 * A value of {@code true} strongly suggests (but does not guarantee)
+	 * that a {@link #getFile()} call will succeed.
+	 * <p>This is conservatively {@code false} by default.
+	 * @since 5.0
+	 * @see #getFile()
+	 */
+	default boolean isFile() {
+		return false;
+	}
 
 	/**
 	 * Return a URL handle for this resource.
@@ -84,6 +100,7 @@ public interface Resource extends InputStreamSource {
 	 * Return a URI handle for this resource.
 	 * @throws IOException if the resource cannot be resolved as URI,
 	 * i.e. if the resource is not available as descriptor
+	 * @since 2.5
 	 */
 	URI getURI() throws IOException;
 

spring-core/src/main/java/org/springframework/core/io/UrlResource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -61,6 +61,7 @@ public class UrlResource extends AbstractFileResolvingResource {
 	 * Create a new {@code UrlResource} based on the given URI object.
 	 * @param uri a URI
 	 * @throws MalformedURLException if the given URL path is not valid
+	 * @since 2.5
 	 */
 	public UrlResource(URI uri) throws MalformedURLException {
 		Assert.notNull(uri, "URI must not be null");
@@ -198,6 +199,16 @@ public URI getURI() throws IOException {
 		}
 	}
 
+	@Override
+	public boolean isFile() {
+		if (this.uri != null) {
+			return super.isFile(this.uri);
+		}
+		else {
+			return super.isFile();
+		}
+	}
+
 	/**
 	 * This implementation returns a File reference for the underlying URL/URI,
 	 * provided that it refers to a file in the file system.

spring-core/src/main/java/org/springframework/core/io/WritableResource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,16 +30,18 @@
 public interface WritableResource extends Resource {
 
 	/**
-	 * Return whether the contents of this resource can be modified,
-	 * e.g. via {@link #getOutputStream()} or {@link #getFile()}.
+	 * Indicate whether the contents of this resource can be written
+	 * via {@link #getOutputStream()}.
 	 * <p>Will be {@code true} for typical resource descriptors;
 	 * note that actual content writing may still fail when attempted.
 	 * However, a value of {@code false} is a definitive indication
 	 * that the resource content cannot be modified.
 	 * @see #getOutputStream()
 	 * @see #isReadable()
 	 */
-	boolean isWritable();
+	default boolean isWritable() {
+		return true;
+	}
 
 	/**
 	 * Return an {@link OutputStream} for the underlying resource,

spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java

@@ -16,8 +16,6 @@
 
 package org.springframework.util;
 
-import java.io.IOException;
-import java.io.InputStream;
 import java.nio.charset.Charset;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.ArrayList;
@@ -28,13 +26,8 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Random;
-import javax.activation.FileTypeMap;
-import javax.activation.MimetypesFileTypeMap;
 
-import org.springframework.core.io.ClassPathResource;
-import org.springframework.core.io.Resource;
 import org.springframework.util.MimeType.SpecificityComparator;
 
 /**
@@ -56,12 +49,6 @@ public abstract class MimeTypeUtils {
 
 	private static Charset US_ASCII = Charset.forName("US-ASCII");
 
-	private static final FileTypeMap fileTypeMap;
-
-	static {
-		fileTypeMap = initFileTypeMap();
-	}
-
 	/**
 	 * Public constant mime type that includes all media ranges (i.e. "*/*").
 	 */
@@ -220,31 +207,6 @@ public abstract class MimeTypeUtils {
 		TEXT_XML = MimeType.valueOf(TEXT_XML_VALUE);
 	}
 
-	private static FileTypeMap initFileTypeMap() {
-		// See if we can find the extended mime.types from the context-support module...
-		Resource mappingLocation = new ClassPathResource("org/springframework/mail/javamail/mime.types");
-		if (mappingLocation.exists()) {
-			InputStream inputStream = null;
-			try {
-				inputStream = mappingLocation.getInputStream();
-				return new MimetypesFileTypeMap(inputStream);
-			}
-			catch (IOException ex) {
-				// ignore
-			}
-			finally {
-				if (inputStream != null) {
-					try {
-						inputStream.close();
-					}
-					catch (IOException ex) {
-						// ignore
-					}
-				}
-			}
-		}
-		return FileTypeMap.getDefaultFileTypeMap();
-	}
 
 	/**
 	 * Parse the given String into a single {@code MimeType}.
@@ -322,23 +284,6 @@ public static List<MimeType> parseMimeTypes(String mimeTypes) {
 		return result;
 	}
 
-	/**
-	 * Returns the {@code MimeType} of the given file name, using the Java Activation
-	 * Framework.
-	 * @param filename the filename whose mime type is to be found
-	 * @return the mime type, if any
-	 * @since 5.0
-	 */
-	public static Optional<MimeType> getMimeType(String filename) {
-		if (filename != null) {
-			String mimeType = fileTypeMap.getContentType(filename);
-			if (StringUtils.hasText(mimeType)) {
-				return Optional.of(parseMimeType(mimeType));
-			}
-		}
-		return Optional.empty();
-	}
-
 	/**
 	 * Return a string representation of the given list of {@code MimeType} objects.
 	 * @param mimeTypes the string to parse