Kiview ftpclient (#4456)

* Add example for FTP client

Using Apache Commons Net

* Add missing resource

* Fix wrong file download in integration test

* Add example for using FTP support in JDK

* Close input stream after copy

* Fix test name

libraries/pom.xml

@@ -709,6 +709,20 @@
             <artifactId>xchart</artifactId>
             <version>${xchart-version}</version>
         </dependency>
+
+        <dependency>
+            <groupId>commons-net</groupId>
+            <artifactId>commons-net</artifactId>
+            <version>${commons-net.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.mockftpserver</groupId>
+            <artifactId>MockFtpServer</artifactId>
+            <version>${mockftpserver.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+
     </dependencies>
 
     <repositories>
@@ -923,6 +937,8 @@
         <typesafe-akka.version>2.5.11</typesafe-akka.version>
         <common-math3-version>3.6.1</common-math3-version>
         <xchart-version>3.5.2</xchart-version>
+        <commons-net.version>3.6</commons-net.version>
+        <mockftpserver.version>2.7.1</mockftpserver.version>
     </properties>
 
 </project>

libraries/src/main/java/com/baeldung/ftp/FtpClient.java

@@ -0,0 +1,63 @@
+package com.baeldung.ftp;
+
+import org.apache.commons.net.PrintCommandListener;
+import org.apache.commons.net.ftp.FTPClient;
+import org.apache.commons.net.ftp.FTPFile;
+import org.apache.commons.net.ftp.FTPReply;
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+class FtpClient {
+
+    private final String server;
+    private final int port;
+    private final String user;
+    private final String password;
+    private FTPClient ftp;
+
+    FtpClient(String server, int port, String user, String password) {
+        this.server = server;
+        this.port = port;
+        this.user = user;
+        this.password = password;
+    }
+
+    void open() throws IOException {
+        ftp = new FTPClient();
+
+        ftp.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
+
+        ftp.connect(server, port);
+        int reply = ftp.getReplyCode();
+        if (!FTPReply.isPositiveCompletion(reply)) {
+            ftp.disconnect();
+            throw new IOException("Exception in connecting to FTP Server");
+        }
+
+        ftp.login(user, password);
+    }
+
+    void close() throws IOException {
+        ftp.disconnect();
+    }
+
+    Collection<String> listFiles(String path) throws IOException {
+        FTPFile[] files = ftp.listFiles(path);
+
+        return Arrays.stream(files)
+                .map(FTPFile::getName)
+                .collect(Collectors.toList());
+    }
+
+    void putFileToPath(File file, String path) throws IOException {
+        ftp.storeFile(path, new FileInputStream(file));
+    }
+
+    void downloadFile(String source, String destination) throws IOException {
+        FileOutputStream out = new FileOutputStream(destination);
+        ftp.retrieveFile(source, out);
+    }
+}

libraries/src/main/java/com/baeldung/javalin/User/UserController.java

@@ -14,7 +14,7 @@ public class UserController {
     public static Handler fetchById = ctx -> {
         int id = Integer.parseInt(Objects.requireNonNull(ctx.param("id")));
         UserDao dao = UserDao.instance();
-        User user = dao.getUserById(id);
+        User user = dao.getUserById(id).get();
         if (user == null) {
             ctx.html("Not Found");
         } else {

libraries/src/test/java/com/baeldung/ftp/FtpClientIntegrationTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.ftp;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockftpserver.fake.FakeFtpServer;
+import org.mockftpserver.fake.UserAccount;
+import org.mockftpserver.fake.filesystem.DirectoryEntry;
+import org.mockftpserver.fake.filesystem.FileEntry;
+import org.mockftpserver.fake.filesystem.FileSystem;
+import org.mockftpserver.fake.filesystem.UnixFakeFileSystem;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.Collection;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class FtpClientIntegrationTest {
+
+    private FakeFtpServer fakeFtpServer;
+
+    private FtpClient ftpClient;
+
+    @Before
+    public void setup() throws IOException {
+        fakeFtpServer = new FakeFtpServer();
+        fakeFtpServer.addUserAccount(new UserAccount("user", "password", "/data"));
+
+        FileSystem fileSystem = new UnixFakeFileSystem();
+        fileSystem.add(new DirectoryEntry("/data"));
+        fileSystem.add(new FileEntry("/data/foobar.txt", "abcdef 1234567890"));
+        fakeFtpServer.setFileSystem(fileSystem);
+        fakeFtpServer.setServerControlPort(0);
+
+        fakeFtpServer.start();
+
+        ftpClient = new FtpClient("localhost", fakeFtpServer.getServerControlPort(), "user", "password");
+        ftpClient.open();
+    }
+
+    @After
+    public void teardown() throws IOException {
+        ftpClient.close();
+        fakeFtpServer.stop();
+    }
+
+    @Test
+    public void givenRemoteFile_whenListingRemoteFiles_thenItIsContainedInList() throws IOException {
+        Collection<String> files = ftpClient.listFiles("");
+
+        assertThat(files).contains("foobar.txt");
+    }
+
+    @Test
+    public void givenRemoteFile_whenDownloading_thenItIsOnTheLocalFilesystem() throws IOException {
+        ftpClient.downloadFile("/foobar.txt", "downloaded_buz.txt");
+
+        assertThat(new File("downloaded_buz.txt")).exists();
+        new File("downloaded_buz.txt").delete(); // cleanup
+    }
+
+    @Test
+    public void givenLocalFile_whenUploadingIt_thenItExistsOnRemoteLocation() throws URISyntaxException, IOException {
+        File file = new File(getClass().getClassLoader().getResource("ftp/baz.txt").toURI());
+
+        ftpClient.putFileToPath(file, "/buz.txt");
+
+        assertThat(fakeFtpServer.getFileSystem().exists("/buz.txt")).isTrue();
+    }
+
+}

libraries/src/test/java/com/baeldung/ftp/JdkFtpClientIntegrationTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.ftp;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockftpserver.fake.FakeFtpServer;
+import org.mockftpserver.fake.UserAccount;
+import org.mockftpserver.fake.filesystem.DirectoryEntry;
+import org.mockftpserver.fake.filesystem.FileEntry;
+import org.mockftpserver.fake.filesystem.FileSystem;
+import org.mockftpserver.fake.filesystem.UnixFakeFileSystem;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.nio.file.Files;
+import java.util.Collection;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JdkFtpClientIntegrationTest {
+
+    private FakeFtpServer fakeFtpServer;
+
+
+    @Before
+    public void setup() throws IOException {
+        fakeFtpServer = new FakeFtpServer();
+        fakeFtpServer.addUserAccount(new UserAccount("user", "password", "/data"));
+
+        FileSystem fileSystem = new UnixFakeFileSystem();
+        fileSystem.add(new DirectoryEntry("/data"));
+        fileSystem.add(new FileEntry("/data/foobar.txt", "abcdef 1234567890"));
+        fakeFtpServer.setFileSystem(fileSystem);
+        fakeFtpServer.setServerControlPort(0);
+
+        fakeFtpServer.start();
+    }
+
+    @After
+    public void teardown() throws IOException {
+        fakeFtpServer.stop();
+    }
+
+    @Test
+    public void givenRemoteFile_whenDownloading_thenItIsOnTheLocalFilesystem() throws IOException {
+        String ftpUrl = String.format("ftp://user:password@localhost:%d/foobar.txt", fakeFtpServer.getServerControlPort());
+
+        URLConnection urlConnection = new URL(ftpUrl).openConnection();
+        InputStream inputStream = urlConnection.getInputStream();
+        Files.copy(inputStream, new File("downloaded_buz.txt").toPath());
+        inputStream.close();
+
+        assertThat(new File("downloaded_buz.txt")).exists();
+
+        new File("downloaded_buz.txt").delete(); // cleanup
+    }
+
+}

spring-boot-ops/README.md

@@ -1,3 +1,3 @@
-### Relevant articles
+### Relevant Articles:
 
 - [Deploy a Spring Boot WAR into a Tomcat Server](http://www.baeldung.com/spring-boot-war-tomcat-deploy)