FilesystemImagePersistenceStrategy: fix path to the file which prevents it to be saved to the disk.

Before MultipartFile.transferTo() tries to save the file relatively to directory from
multipart-config/location (in web.xml). As result instead of put file to /data/uploads it tries to
write it to /tmp/data/uploads and because intermediate directories doesn't exist it silently exits.

See also my question at SO about spy objects:
http://stackoverflow.com/questions/21562276/how-to-verify-argument-of-method-of-spying-object

Addressed to #132

Author: php-coder

src/main/java/ru/mystamps/web/service/FilesystemImagePersistenceStrategy.java

@@ -18,11 +18,13 @@
 package ru.mystamps.web.service;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 
 import javax.annotation.PostConstruct;
 
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -65,15 +67,12 @@ public void init() {
 	public void save(MultipartFile file, Image image) {
 		try {
 			File dest = createFile(image);
-			file.transferTo(dest);
+			writeToFile(file, dest);
 
 			LOG.debug("Image's data was written into file {}", dest);
 
 		} catch (IOException ex) {
 			throw new ImagePersistenceException(ex);
-		
-		} catch (IllegalStateException ex) {
-			throw new ImagePersistenceException(ex);
 		}
 	}
 
@@ -98,7 +97,15 @@ public ImageDto get(Image image) {
 	protected File createFile(Image image) {
 		return new File(storageDir, generateFileName(image));
 	}
-
+	
+	// protected to allow spying
+	protected void writeToFile(MultipartFile file, File dest) throws IOException {
+		// we can't use file.transferTo(dest) there because it creates file
+		// relatively to directory from multipart-config/location in web.xml
+		// TODO(java7): use Files.copy() instead
+		IOUtils.copy(file.getInputStream(), new FileOutputStream(dest));
+	}
+	
 	// protected to allow spying
 	protected byte[] toByteArray(File dest) throws IOException {
 		// TODO(guava): use Files.toByteArray()

src/test/groovy/ru/mystamps/web/service/FilesystemImagePersistenceStrategyTest.groovy

@@ -42,7 +42,7 @@ class FilesystemImagePersistenceStrategyTest extends Specification {
 		when:
 			strategy.save(multipartFile, image)
 		then:
-			1 * multipartFile.transferTo(_ as File)
+			1 * strategy.writeToFile(_ as MultipartFile, _ as File) >> {}
 	}
 
 	def "save() should saves file onto the configured directory"() {
@@ -51,10 +51,10 @@ class FilesystemImagePersistenceStrategyTest extends Specification {
 		when:
 			strategy.save(multipartFile, image)
 		then:
-			1 * multipartFile.transferTo({File file ->
+			1 * strategy.writeToFile(_ as MultipartFile, { File file ->
 				assert file.parent == expectedDirectoryName
 				return true
-			})
+			}) >> {}
 	}
 
 	def "save() should gives proper name to the file"() {
@@ -65,15 +65,15 @@ class FilesystemImagePersistenceStrategyTest extends Specification {
 		when:
 			strategy.save(multipartFile, image)
 		then:
-			1 * multipartFile.transferTo({File file ->
+			1 * strategy.writeToFile(_ as MultipartFile, { File file ->
 				assert file.name == expectedFileName
 				return true
-			})
+			}) >> {}
 	}
 
 	def "save() should converts IOException to ImagePersistenceException"() {
 		given:
-			multipartFile.transferTo(_ as File) >> { throw new IOException() }
+			strategy.writeToFile(_ as MultipartFile, _ as File) >> { throw new IOException() }
 		when:
 			strategy.save(multipartFile, image)
 		then:
@@ -82,17 +82,6 @@ class FilesystemImagePersistenceStrategyTest extends Specification {
 			ex.cause instanceof IOException
 	}
 
-	def "save() should converts IllegalStateException to ImagePersistenceException"() {
-		given:
-			multipartFile.transferTo(_ as File) >> { throw new IllegalStateException() }
-		when:
-			strategy.save(multipartFile, image)
-		then:
-			ImagePersistenceException ex = thrown()
-		and:
-			ex.cause instanceof IllegalStateException
-	}
-	
 	//
 	// Tests for get()
 	//