New NamedDataSource

src/main/java/org/simplejavamail/mailer/internal/datasource/NamedDataSource.java

@@ -0,0 +1,92 @@
+package org.simplejavamail.mailer.internal.datasource;
+
+import javax.activation.DataSource;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Data source used to fix bug, when user try to use different name for file in {@link javax.activation.FileDataSource},
+ * than the actual name is.
+ *
+ * @author Lukas Kosina
+ * @see DataSource
+ * @see javax.activation.FileDataSource
+ */
+public class NamedDataSource implements DataSource {
+
+    /**
+     * Original data source used for attachment
+     */
+    private final DataSource dataSource;
+    /**
+     * The new name, which will be applied as email attachment
+     */
+    private final String name;
+
+    /**
+     * Constructor. Used for wrapping data source in parameter. Method {@link NamedDataSource#getName()} will
+     * use original name of the data source
+     *
+     * @param dataSource wrapped data source
+     */
+    public NamedDataSource(DataSource dataSource) {
+        this.dataSource = dataSource;
+        this.name = null;
+    }
+
+    /**
+     * Constructor. Used for wrapping data source in parameter. Method {@link NamedDataSource#getName()} will
+     * not use the original name, but it will use the name in the parameter instead.
+     *
+     * @param dataSource wrapped data source
+     * @param name       new name of data source
+     */
+    public NamedDataSource(String name, DataSource dataSource) {
+        this.dataSource = dataSource;
+        this.name = name;
+    }
+
+    /**
+     * Return the input stream from {@link #dataSource}
+     *
+     * @return input stream
+     * @throws IOException if exception occurs during getting input stream from {@link #dataSource}
+     */
+    @Override
+    public InputStream getInputStream() throws IOException {
+        return dataSource.getInputStream();
+    }
+
+    /**
+     * Return the output stream from {@link #dataSource}
+     *
+     * @return output stream
+     * @throws IOException if exception occurs during getting output stream from {@link #dataSource}
+     */
+    @Override
+    public OutputStream getOutputStream() throws IOException {
+        return dataSource.getOutputStream();
+    }
+
+    /**
+     * Return the original content type from {@link #dataSource}
+     *
+     * @return content type of data source
+     */
+    @Override
+    public String getContentType() {
+        return dataSource.getContentType();
+    }
+
+    /**
+     * If parameter {@link #name} is set, then return the value of parameter name. Otherwise, return the name of the
+     * {@link #dataSource}
+     *
+     * @return name of data source
+     */
+    @Override
+    public String getName() {
+        return name != null ? name : dataSource.getName();
+    }
+}

src/main/java/org/simplejavamail/mailer/internal/mailsender/MimeMessageHelper.java

@@ -7,6 +7,7 @@
 import org.simplejavamail.email.AttachmentResource;
 import org.simplejavamail.email.Email;
 import org.simplejavamail.email.Recipient;
+import org.simplejavamail.mailer.internal.datasource.NamedDataSource;
 
 import javax.activation.DataHandler;
 import javax.activation.DataSource;
@@ -29,15 +30,15 @@
  */
 public final class MimeMessageHelper {
 
-	private MimeMessageHelper() {
-
-	}
-
 	/**
 	 * Encoding used for setting body text, email address, headers, reply-to fields etc. ({@link StandardCharsets#UTF_8}).
 	 */
 	private static final String CHARACTER_ENCODING = StandardCharsets.UTF_8.name();
 
+	private MimeMessageHelper() {
+
+	}
+
 	/**
 	 * Creates a new {@link MimeMessage} instance coupled to a specific {@link Session} instance and prepares it in the email structure, so that it
 	 * can be filled and send.
@@ -207,7 +208,7 @@ private static BodyPart getBodyPartFromDatasource(final AttachmentResource attac
 		// setting headers isn't working nicely using the javax mail API, so let's do that manually
 		String resourceName = determineResourceName(attachmentResource, false);
 		String fileName = determineResourceName(attachmentResource, true);
-		attachmentPart.setDataHandler(new DataHandler(attachmentResource.getDataSource()));
+		attachmentPart.setDataHandler(new DataHandler(new NamedDataSource(fileName, attachmentResource.getDataSource())));
 		attachmentPart.setFileName(fileName);
 		String contentType = attachmentResource.getDataSource().getContentType();
 		attachmentPart.setHeader("Content-Type", contentType + "; filename=" + fileName + "; name=" + resourceName);

src/test/java/org/simplejavamail/mailer/internal/datasource/NamedDataSourceTest.java

@@ -0,0 +1,81 @@
+package org.simplejavamail.mailer.internal.datasource;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import javax.activation.DataSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.*;
+
+@RunWith(MockitoJUnitRunner.class)
+public class NamedDataSourceTest {
+
+    @Mock
+    private DataSource dataSource;
+
+    @Before
+    public void setUp() throws Exception {
+        when(dataSource.getName()).thenReturn("testName");
+    }
+
+    @Test
+    public void renameWillWork() throws Exception {
+        DataSource testDataSource = new NamedDataSource("newName", dataSource);
+        assertThat(testDataSource.getName()).isEqualTo("newName");
+        verifyZeroInteractions(dataSource);
+    }
+
+    @Test
+    public void originalNameWillWork() throws Exception {
+        DataSource testDataSource = new NamedDataSource(dataSource);
+        assertThat(testDataSource.getName()).isEqualTo("testName");
+        verify(dataSource).getName();
+    }
+
+    @Test
+    public void inputStreamWillBeTheSame1() throws Exception {
+        DataSource testDataSource = new NamedDataSource("newName", dataSource);
+        testDataSource.getInputStream();
+        verify(dataSource).getInputStream();
+    }
+
+    @Test
+    public void inputStreamWillBeTheSame2() throws Exception {
+        DataSource testDataSource = new NamedDataSource(dataSource);
+        testDataSource.getInputStream();
+        verify(dataSource).getInputStream();
+    }
+
+    @Test
+    public void outputStreamWillBeTheSame1() throws Exception {
+        DataSource testDataSource = new NamedDataSource("newName", dataSource);
+        testDataSource.getOutputStream();
+        verify(dataSource).getOutputStream();
+    }
+
+    @Test
+    public void outputStreamWillBeTheSame2() throws Exception {
+        DataSource testDataSource = new NamedDataSource(dataSource);
+        testDataSource.getOutputStream();
+        verify(dataSource).getOutputStream();
+    }
+
+    @Test
+    public void contentTypeStreamWillBeTheSame1() throws Exception {
+        DataSource testDataSource = new NamedDataSource("newName", dataSource);
+        testDataSource.getContentType();
+        verify(dataSource).getContentType();
+    }
+
+    @Test
+    public void contentTypeStreamWillBeTheSame2() throws Exception {
+        DataSource testDataSource = new NamedDataSource(dataSource);
+        testDataSource.getContentType();
+        verify(dataSource).getContentType();
+    }
+
+}