Add Apache MINA SftpEventListener

- republish certain events as `ApplicationEvent`s.

* * Add ApacheMinaFtplet to provide the same functionality with FTP
* Fix typo

* * Polishing javadocs and event toString() methods

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/ApacheMinaFtpEvent.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpSession;
+
+import org.springframework.integration.file.remote.server.FileServerEvent;
+
+/**
+ * {@code ApplicationEvent} generated from Apache Mina ftp events.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public abstract class ApacheMinaFtpEvent extends FileServerEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	public ApacheMinaFtpEvent(Object source) {
+		super(source);
+	}
+
+	public ApacheMinaFtpEvent(Object source, Throwable cause) {
+		super(source, cause);
+	}
+
+	public FtpSession getSession() {
+		return (FtpSession) source;
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + " [clientAddress=" + getSession().getClientAddress() + "]";
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/ApacheMinaFtplet.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import java.io.IOException;
+
+import org.apache.ftpserver.ftplet.DefaultFtplet;
+import org.apache.ftpserver.ftplet.FtpException;
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+import org.apache.ftpserver.ftplet.FtpletResult;
+
+import org.springframework.beans.factory.BeanNameAware;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.context.ApplicationEventPublisherAware;
+import org.springframework.util.Assert;
+
+/**
+ * A listener for FTP events emitted by an Apache Mina ftp server.
+ * It emits selected events as Spring Framework {@code ApplicationEvent}s
+ * which are subclasses of {@link ApacheMinaFtpEvent}.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class ApacheMinaFtplet extends DefaultFtplet
+		implements ApplicationEventPublisherAware, BeanNameAware, InitializingBean {
+
+	private ApplicationEventPublisher applicationEventPublisher;
+
+	private String beanName;
+
+	@Override
+	public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
+		this.applicationEventPublisher = applicationEventPublisher;
+	}
+
+	protected ApplicationEventPublisher getApplicationEventPublisher() {
+		return this.applicationEventPublisher;
+	}
+
+	@Override
+	public void setBeanName(String name) {
+		this.beanName = name;
+	}
+
+	public String getBeanName() {
+		return this.beanName;
+	}
+
+	@Override
+	public void afterPropertiesSet() {
+		Assert.state(this.applicationEventPublisher != null, "An ApplicationEventPublisher is required");
+	}
+
+	@Override
+	public FtpletResult onConnect(FtpSession session) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new SessionOpenedEvent(session));
+		return super.onConnect(session);
+	}
+
+	@Override
+	public FtpletResult onDisconnect(FtpSession session) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new SessionClosedEvent(session));
+		return super.onDisconnect(session);
+	}
+
+	@Override
+	public FtpletResult onDeleteEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new PathRemovedEvent(session, request, false));
+		return super.onDeleteEnd(session, request);
+	}
+
+	@Override
+	public FtpletResult onUploadEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new FileWrittenEvent(session, request, false));
+		return super.onUploadEnd(session, request);
+	}
+
+	@Override
+	public FtpletResult onRmdirEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new PathRemovedEvent(session, request, true));
+		return super.onRmdirEnd(session, request);
+	}
+
+	@Override
+	public FtpletResult onMkdirEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new DirectoryCreatedEvent(session, request));
+		return super.onMkdirEnd(session, request);
+	}
+
+	@Override
+	public FtpletResult onAppendEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new FileWrittenEvent(session, request, false));
+		return super.onAppendEnd(session, request);
+	}
+
+	@Override
+	public FtpletResult onRenameEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
+		this.applicationEventPublisher.publishEvent(new PathMovedEvent(session, request));
+		return super.onRenameEnd(session, request);
+	}
+
+	@Override
+	public String toString() {
+		return "ApacheMinaSftpEventListener [beanName=" + this.beanName + "]";
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/DirectoryCreatedEvent.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event emitted when a directory is created.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class DirectoryCreatedEvent extends FtpRequestEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	public DirectoryCreatedEvent(FtpSession source, FtpRequest request) {
+		super(source, request);
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/FileWrittenEvent.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event that is emitted when a file is written.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class FileWrittenEvent extends FtpRequestEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	private final boolean append;
+
+	public FileWrittenEvent(FtpSession source, FtpRequest request, boolean append) {
+		super(source, request);
+		this.append = append;
+	}
+
+	public boolean isAppend() {
+		return this.append;
+	}
+
+	@Override
+	public String toString() {
+		return "FileWrittenEvent [append=" + this.append
+				+ ", request=" + this.request
+				+ ", clientAddress=" + getSession().getClientAddress() + "]";
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/FtpRequestEvent.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * Base class for all events having an {@link FtpRequest}.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public abstract class FtpRequestEvent extends ApacheMinaFtpEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	protected final FtpRequest request; //NOSONAR protected final
+
+	public FtpRequestEvent(FtpSession source, FtpRequest request) {
+		super(source);
+		this.request = request;
+	}
+
+	public FtpRequest getRequest() {
+		return this.request;
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + " [request=" + this.request
+				+ ", clientAddress=" + getSession().getClientAddress() + "]";
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/PathMovedEvent.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event emitted when a path is moved.
+ * @author Gary Russell
+ *
+ * @since 5.2
+ *
+ */
+public class PathMovedEvent extends FtpRequestEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	public PathMovedEvent(FtpSession source, FtpRequest request) {
+		super(source, request);
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/PathRemovedEvent.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpRequest;
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event emitted when a file or directory is removed.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class PathRemovedEvent extends FtpRequestEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	private final boolean isDirectory;
+
+	public PathRemovedEvent(FtpSession source, FtpRequest request, boolean isDirectory) {
+		super(source, request);
+		this.isDirectory = isDirectory;
+	}
+
+	public boolean isDirectory() {
+		return this.isDirectory;
+	}
+
+	@Override
+	public String toString() {
+		return "PathRemovedEvent [isDirectory=" + this.isDirectory
+				+ ", request=" + this.request
+				+ ", clientAddress=" + getSession().getClientAddress() + "]";
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/SessionClosedEvent.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event emitted when a session is closed.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class SessionClosedEvent extends ApacheMinaFtpEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	public SessionClosedEvent(FtpSession session) {
+		super(session);
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/SessionOpenedEvent.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2019 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
+ *
+ *      https://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.ftp.server;
+
+import org.apache.ftpserver.ftplet.FtpSession;
+
+/**
+ * An event emitted when a session is opened.
+ *
+ * @author Gary Russell
+ * @since 5.2
+ *
+ */
+public class SessionOpenedEvent extends ApacheMinaFtpEvent {
+
+	private static final long serialVersionUID = 1L;
+
+	public SessionOpenedEvent(FtpSession session) {
+		super(session);
+	}
+
+}

spring-integration-ftp/src/main/java/org/springframework/integration/ftp/server/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Provides classes related to FTP servers.
+ */
+package org.springframework.integration.ftp.server;