BAEL-1934 (#4768)

* Bean Object, server side and client side example for event streaming
example

* BAEL-1628

Access a File from the Classpath in a Spring Application

* inputstream retrieval added

* Removed files related to evaluation article

* + Aligning code to the article. Removed Utility methods and classes

* BAEL - 1628

* PMD fixes

* Code Review changes
Refactored : whenResourceUtils_thenReadSuccessful

* BAEL-1934

* +indentation correction in pom.xml

* synced with master

* indentation correction

core-java/pom.xml

@@ -147,6 +147,17 @@
             <artifactId>icu4j</artifactId>
             <version>${icu4j.version}</version>
         </dependency>
+        <!-- Mime Type Resolution Libraries -->
+        <dependency>
+            <groupId>org.apache.tika</groupId>
+            <artifactId>tika-core</artifactId>
+            <version>${tika.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>net.sf.jmimemagic</groupId>
+            <artifactId>jmimemagic</artifactId>
+            <version>${jmime-magic.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-dbcp2</artifactId>
@@ -439,6 +450,9 @@
         <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
         <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
         <icu4j.version>61.1</icu4j.version>
+        <!-- Mime Type Libraries -->
+        <tika.version>1.18</tika.version>
+        <jmime-magic.version>0.1.5</jmime-magic.version>
     </properties>
 
 </project>

core-java/src/test/java/com/baeldung/java/mimetype/MimeTypeUnitTest.java

@@ -0,0 +1,131 @@
+package com.baeldung.java.mimetype;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.FileNameMap;
+import java.net.MalformedURLException;
+import java.net.URLConnection;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import javax.activation.MimetypesFileTypeMap;
+
+import org.apache.tika.Tika;
+import org.junit.Test;
+
+import net.sf.jmimemagic.Magic;
+import net.sf.jmimemagic.MagicException;
+import net.sf.jmimemagic.MagicMatch;
+import net.sf.jmimemagic.MagicMatchNotFoundException;
+import net.sf.jmimemagic.MagicParseException;
+
+/**
+ * Test class demonstrating various strategies to resolve MIME type of a file.
+ * @author tritty
+ *
+ */
+public class MimeTypeUnitTest {
+    /**
+     * Expected Ouput.
+     */
+    public static final String PNG_EXT = "image/png";
+
+    /**
+     * The location of the file.
+     */
+    public static final String FILE_LOC = "src/test/resources/product.png";
+
+    /**
+     * Test method, demonstrating usage in Java 7.
+     * 
+     * @throws IOException
+     */
+    @Test
+    public void whenUsingJava7_thenSuccess() throws IOException {
+        final Path path = new File(FILE_LOC).toPath();
+        final String mimeType = Files.probeContentType(path);
+        assertEquals(mimeType, PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating the usage of URLConnection to resolve MIME type.
+     * 
+     * @throws MalformedURLException
+     * @throws IOException
+     */
+    @Test
+    public void whenUsingGetContentType_thenSuccess() throws MalformedURLException, IOException {
+        final File file = new File(FILE_LOC);
+        final URLConnection connection = file.toURL()
+            .openConnection();
+        final String mimeType = connection.getContentType();
+        assertEquals(mimeType, PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating the usage of URLConnection to resolve MIME type.
+     * 
+     */
+    @Test
+    public void whenUsingGuessContentTypeFromName_thenSuccess() {
+        final File file = new File(FILE_LOC);
+        final String mimeType = URLConnection.guessContentTypeFromName(file.getName());
+        assertEquals(mimeType, PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating the usage of FileNameMap from URLConnection
+     * to resolve MIME type of a file.
+     * 
+     */
+    @Test
+    public void whenUsingGetFileNameMap_thenSuccess() {
+        final File file = new File(FILE_LOC);
+        final FileNameMap fileNameMap = URLConnection.getFileNameMap();
+        final String mimeType = fileNameMap.getContentTypeFor(file.getName());
+        assertEquals(mimeType, PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating the usage of MimeTypesFileTypeMap for resolution of 
+     * MIME type.
+     * 
+     */
+    @Test
+    public void whenUsingMimeTypesFileTypeMap_thenSuccess() {
+        final File file = new File(FILE_LOC);
+        final MimetypesFileTypeMap fileTypeMap = new MimetypesFileTypeMap();
+        final String mimeType = fileTypeMap.getContentType(file.getName());
+        assertEquals(mimeType, PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating usage of jMimeMagic.
+     * 
+     * @throws MagicParseException
+     * @throws MagicMatchNotFoundException
+     * @throws MagicException
+     */
+    @Test
+    public void whenUsingJmimeMagic_thenSuccess() throws MagicParseException, MagicMatchNotFoundException, MagicException {
+        final File file = new File(FILE_LOC);
+        final Magic magic = new Magic();
+        final MagicMatch match = magic.getMagicMatch(file, false);
+        assertEquals(match.getMimeType(), PNG_EXT);
+    }
+
+    /**
+     * Test method demonstrating usage of Apache Tika.
+     * 
+     * @throws IOException
+     */
+    @Test
+    public void whenUsingTika_thenSuccess() throws IOException {
+        final File file = new File(FILE_LOC);
+        final Tika tika = new Tika();
+        final String mimeType = tika.detect(file);
+        assertEquals(mimeType, PNG_EXT);
+    }
+}