INT-3773: (S)FTP RemoteFileTemplate Fail/Ignore

JIRA: https://jira.spring.io/browse/INT-3773

When the `FileExistsMode` was `FAIL` or `IGNORE` and the remote file
did NOT exist, the file was not written.

spring-integration-file/src/main/java/org/springframework/integration/file/remote/RemoteFileTemplate.java

@@ -520,6 +520,9 @@ public class RemoteFileTemplate<F> implements RemoteFileOperations<F>, Initializ
 					}
 					rename = false;
 				}
+				else {
+					session.write(inputStream, tempFilePath);
+				}
 			}
 			// then rename it to its final name if necessary
 			if (rename) {

spring-integration-file/src/test/java/org/springframework/integration/file/remote/RemoteFileTemplateTests.java

@@ -0,0 +1,132 @@
+/*
+ * Copyright 2015 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.integration.file.remote;
+
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.integration.file.remote.session.Session;
+import org.springframework.integration.file.remote.session.SessionFactory;
+import org.springframework.integration.file.support.FileExistsMode;
+import org.springframework.messaging.MessagingException;
+import org.springframework.messaging.support.GenericMessage;
+
+import org.hamcrest.Matchers;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.mockito.Mockito;
+
+/**
+ * @author Gary Russell
+ * @since 4.1.7
+ *
+ */
+public class RemoteFileTemplateTests {
+
+	private RemoteFileTemplate<Object> template;
+
+	private Session<Object> session;
+
+	@Rule
+	public TemporaryFolder folder = new TemporaryFolder();
+
+	private File file;
+
+	@SuppressWarnings("unchecked")
+	@Before
+	public void setUp() throws Exception {
+		SessionFactory<Object> sessionFactory = mock(SessionFactory.class);
+		this.template = new RemoteFileTemplate<Object>(sessionFactory) {
+
+			@Override
+			public boolean exists(String path) {
+				try {
+					return sessionFactory.getSession().exists(path);
+				}
+				catch (IOException e) {
+					return false;
+				}
+			}
+
+		};
+		this.template.setRemoteDirectoryExpression(new LiteralExpression("/foo"));
+		this.template.setBeanFactory(mock(BeanFactory.class));
+		this.template.afterPropertiesSet();
+		this.session = mock(Session.class);
+		when(sessionFactory.getSession()).thenReturn(this.session);
+		this.file = this.folder.newFile();
+	}
+
+	@Test
+	public void testReplace() throws Exception {
+		this.template.send(new GenericMessage<File>(this.file), FileExistsMode.REPLACE);
+		verify(this.session).write(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+	@Test
+	public void testAppend() throws Exception {
+		this.template.setUseTemporaryFileName(false);
+		this.template.send(new GenericMessage<File>(this.file), FileExistsMode.APPEND);
+		verify(this.session).append(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+	@Test
+	public void testFailExists() throws Exception {
+		when(session.exists(Mockito.anyString())).thenReturn(true);
+		try {
+			this.template.send(new GenericMessage<File>(this.file), FileExistsMode.FAIL);
+			fail("Expected exception");
+		}
+		catch (MessagingException e) {
+			assertThat(e.getMessage(), Matchers.containsString("The destination file already exists"));
+		}
+		verify(this.session, never()).write(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+	@Test
+	public void testIgnoreExists() throws Exception {
+		when(session.exists(Mockito.anyString())).thenReturn(true);
+		this.template.send(new GenericMessage<File>(this.file), FileExistsMode.IGNORE);
+		verify(this.session, never()).write(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+	@Test
+	public void testFailNotExists() throws Exception {
+		when(session.exists(Mockito.anyString())).thenReturn(false);
+		this.template.send(new GenericMessage<File>(this.file), FileExistsMode.FAIL);
+		verify(this.session).write(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+	@Test
+	public void testIgnoreNotExists() throws Exception {
+		when(session.exists(Mockito.anyString())).thenReturn(false);
+		this.template.send(new GenericMessage<File>(this.file), FileExistsMode.IGNORE);
+		verify(this.session).write(Mockito.any(InputStream.class), Mockito.anyString());
+	}
+
+}