Sqlite as storage backend (#1)

Some platforms has some problems with file locking, so I was forced to use an alternative. SQLite seems be the best option currently available


* Migrated to an sqlite database

* Removed unnecessary IOExceptions

* Removed an util class not needed anymore

* Updated README.md and docker-compose.yml to reflect new storage mechanism

.gitignore

@@ -10,3 +10,4 @@ url.iml
 .settings/
 urls.csv
 .env
+urls.sqlite

README.md

@@ -13,7 +13,7 @@ unnecessary features, or they didn't have all the features I wanted.
   to the correct long URL (you'd think that's a standard feature, but
   apparently it's not)
 - Provides a simple API for adding new short links
-- Links are stored in a plaintext CSV file
+- Links are stored in an SQLite database
 - Available as a Docker container (there is no image on docker hub _yet_)
 - Backend written in Java using [Spark Java](http://sparkjava.com/), frontend
   written in plain HTML and vanilla JS, using [Pure CSS](https://purecss.io/)
@@ -45,9 +45,11 @@ in order to speed up future builds.
 
 ### 2. Set environment variables
 ```bash
+# Required for authentication
 export username=<api username>
 export password=<api password>
-export file.location=<file location> # opitonal
+# Sets where the database exists. Can be local or remote (optional)
+export db.url=<url> # Default: './urls.sqlite'
 ```
 
 ### 3. Run it
@@ -64,20 +66,24 @@ docker build . -t url:latest
 ```
 2. Run the image
 ```
-docker run -p 4567:4567 -d url:latest
+docker run -p 4567:4567
+    -d url:latest
+    -e username="username"
+    -e password="password"
+    -d url:latest
 ```
-2.a Make the CSV file available to host
+2.a Make the database file available to host (optional)
 ```
 touch ./urls.csv
 docker run -p 4567:4567 \
-	-e file.location=/urls.csv \
-    -e username="username"
-    -e password="password"
-	-v ./urls.csv:/urls.csv \
-	-d url:1.0
+    -e username="username" \
+    -e password="password" \
+    -v ./urls.sqlite:/urls.csv \
+    -e db.url=/urls.csv \
+    -d url:latest
 ```
 ## `docker-compose`
-There is a sample `docker-compose.yml` file in this repository. You can use it
+There is a sample `docker-compose.yml` file in this repository configured for Traefik. You can use it
 as a base, modifying it as needed. Run it with
 ```
 docker-compose up -d --build

build.gradle

@@ -24,6 +24,8 @@ jar {
 dependencies {
 	compile "com.sparkjava:spark-core:2.8.0"
     compile 'com.qmetric:spark-authentication:1.4'
+    compile group: 'org.xerial', name: 'sqlite-jdbc', version: '3.30.1'
+
 }
 
 application {

docker-compose.yml

@@ -6,11 +6,11 @@ services:
             context: .
         container_name: url
         environment:
-            - file.location=/urls.csv
+            - db.url=/urls.sqlite
             - username=${URL_LOGIN}
             - password=${URL_PASSWORD}
         volumes:
-            - ./urls.csv:/urls.csv
+            - ./urls.sqlite:/urls.sqlite
         networks:
             - ${NETWORK}
         labels:

src/main/java/tk/draganczuk/url/Pair.java

@@ -1,36 +0,0 @@
-package tk.draganczuk.url;
-
-/**
-* Pair
-*/
-public class Pair<T, U> {
-
-	private T left;
-	private U right;
-
-
-	public Pair(T left, U right) {
-		this.left = left;
-		this.right = right;
-	}
-
-	public static <T, U> Pair<T, U> of(T left, U right){
-		return new Pair<T,U>(left, right);
-	}
-
-	public T getLeft() {
-		return left;
-	}
-
-	public void setLeft(T left) {
-		this.left = left;
-	}
-
-	public U getRight() {
-		return right;
-	}
-
-	public void setRight(U right) {
-		this.right = right;
-	}
-}

src/main/java/tk/draganczuk/url/Routes.java

@@ -8,18 +8,14 @@ import java.io.IOException;
 
 public class Routes {
 
-	private static UrlFile urlFile;
+	private static UrlRepository urlRepository;
 
 	static {
-		try {
-			urlFile = new UrlFile();
-		} catch (IOException e) {
-			e.printStackTrace();
-		}
+		urlRepository = new UrlRepository();
 	}
 
-	public static String getAll(Request req, Response res) throws IOException {
-		return String.join("\n", urlFile.getAll());
+	public static String getAll(Request req, Response res) {
+		return String.join("\n", urlRepository.getAll());
 	}
 
 	public static String addUrl(Request req, Response res) {
@@ -31,7 +27,7 @@ public class Routes {
 		}
 
 		if (Utils.validate(shortUrl)) {
-			return urlFile.addUrl(longUrl, shortUrl);
+			return urlRepository.addUrl(longUrl, shortUrl);
 		} else {
 			res.status(HttpStatus.BAD_REQUEST_400);
 			return "shortUrl not valid ([a-z0-9]+)";
@@ -41,7 +37,7 @@ public class Routes {
 
 	public static String goToLongUrl(Request req, Response res) {
 		String shortUrl = req.params("shortUrl");
-		var longUrlOpt = urlFile
+		var longUrlOpt = urlRepository
 				.findForShortUrl(shortUrl);
 
 		if (longUrlOpt.isEmpty()) {
@@ -56,15 +52,8 @@ public class Routes {
 
 	public static String delete(Request req, Response res) {
 		String shortUrl = req.params("shortUrl");
-		var longUrlOpt = urlFile
-				.findForShortUrl(shortUrl);
 
-		if (longUrlOpt.isEmpty()) {
-			res.status(404);
-			return "";
-		}
-
-		urlFile.deleteEntry(String.format("%s,%s", shortUrl, longUrlOpt.get()));
+		urlRepository.deleteEntry(shortUrl);
 		return "";
 	}
 }

src/main/java/tk/draganczuk/url/UrlFile.java

@@ -1,82 +0,0 @@
-package tk.draganczuk.url;
-
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.StandardCopyOption;
-import java.nio.file.StandardOpenOption;
-import java.util.List;
-import java.util.Optional;
-
-
-public class UrlFile {
-
-	private File file;
-
-	public UrlFile() throws IOException{
-		String path = System.getenv().getOrDefault("file.location", "./urls.csv");
-		this.file = new File(path);
-		if (!file.exists()) {
-			file.createNewFile();
-		}
-	}
-
-	public List<String> getAll() throws IOException{
-		return Files.readAllLines(file.toPath());
-	}
-
-	public String addUrl(String longURL, String shortUrl){
-		String entry = String.format("%s,%s",shortUrl,longURL);
-		try {
-			var lineOpt = Files.lines(file.toPath())
-				.filter(line -> line.equals(entry))
-				.findAny();
-			if(lineOpt.isEmpty()){
-				Files.writeString(file.toPath(), entry + System.lineSeparator(), StandardOpenOption.APPEND);
-			}
-		} catch (IOException e) {
-			e.printStackTrace();
-		}
-		return entry;
-	}
-
-	public Optional<String> findForShortUrl(String shortUrl){
-		try {
-			return Files.lines(file.toPath())
-					.map(this::splitLine)
-					.filter(pair -> pair.getLeft().equals(shortUrl))
-					.map(Pair::getRight)
-					.findAny();
-		} catch (IOException e) {
-			return Optional.empty();
-		}
-	}
-
-	public Pair<String, String> splitLine(String line) {
-		var split = line.split(",");
-		return new Pair<>(split[0], split[1]);
-	}
-
-	public void deleteEntry(String entry) {
-		try {
-			File tmp = File.createTempFile(file.getName(), ".tmp");
-			if (!tmp.exists()) {
-				tmp.createNewFile();
-			}
-
-			Files.lines(file.toPath())
-					.filter(line -> !line.equals(entry))
-					.forEach(line -> {
-						try {
-							Files.writeString(tmp.toPath(), line + "\n", StandardOpenOption.APPEND);
-						} catch (IOException e) {
-							e.printStackTrace();
-						}
-					});
-
-			Files.move(tmp.toPath(), file.toPath(), StandardCopyOption.REPLACE_EXISTING);
-		} catch (IOException e) {
-			e.printStackTrace();
-		}
-	}
-}

src/main/java/tk/draganczuk/url/UrlRepository.java

@@ -0,0 +1,109 @@
+package tk.draganczuk.url;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
+import java.nio.file.StandardOpenOption;
+import java.sql.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+
+public class UrlRepository {
+	private static final String INSERT_ROW_SQL = "INSERT INTO urls (long_url, short_url) VALUES (?, ?)";
+	private static final String CREATE_TABLE_SQL = "CREATE TABLE IF NOT EXISTS urls\n" +
+			"(\n" +
+			"    id          INTEGER PRIMARY KEY AUTOINCREMENT,\n" +
+			"    long_url    TEXT    NOT NULL,\n" +
+			"    short_url   TEXT    NOT NULL\n" +
+			");";
+	private static final String SELECT_FOR_SHORT_SQL = "SELECT long_url FROM urls WHERE short_url = ?";
+	private static final String DELETE_ROW_SQL = "DELETE FROM urls WHERE short_url = ?";
+
+	private String databaseUrl;
+
+
+	public UrlRepository() {
+		String path = System.getenv().getOrDefault("db.url", "./urls.sqlite");
+
+		databaseUrl = "jdbc:sqlite:" + path;
+
+		try (Connection conn = DriverManager.getConnection(databaseUrl)) {
+			if (conn != null) {
+				DatabaseMetaData meta = conn.getMetaData();
+
+				conn.createStatement()
+						.execute(CREATE_TABLE_SQL);
+
+				System.out.println("Database initialised");
+			}
+
+		} catch (SQLException e) {
+			System.out.println(e.getMessage());
+		}
+	}
+
+	public List<String> getAll() {
+		try (final var con = DriverManager.getConnection(databaseUrl)) {
+			var statement = con.createStatement();
+
+			statement.execute("SELECT * FROM urls");
+			ResultSet rs = statement.getResultSet();
+
+			List<String> result = new ArrayList<>();
+
+			while (rs.next()) {
+				result.add(String.format("%s,%s", rs.getString("short_url"), rs.getString("long_url")));
+			}
+
+			return result;
+
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		return List.of();
+	}
+
+	public String addUrl(String longURL, String shortUrl) {
+		try (final var con = DriverManager.getConnection(databaseUrl)) {
+			final var stmt = con.prepareStatement(INSERT_ROW_SQL);
+			stmt.setString(1, longURL);
+			stmt.setString(2, shortUrl);
+			if (stmt.execute()) {
+				return String.format("%s,%s", shortUrl, longURL);
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		return "";
+	}
+
+	public Optional<String> findForShortUrl(String shortUrl) {
+		try (final var con = DriverManager.getConnection(databaseUrl)) {
+			final var stmt = con.prepareStatement(SELECT_FOR_SHORT_SQL);
+			stmt.setString(1, shortUrl);
+			if (stmt.execute()) {
+				ResultSet rs = stmt.getResultSet();
+				if (rs.next()) {
+					return Optional.of(rs.getString("long_url"));
+				}
+			}
+			return Optional.empty();
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+		return Optional.empty();
+	}
+
+	public void deleteEntry(String shortUrl) {
+		try (final var con = DriverManager.getConnection(databaseUrl)) {
+			final var stmt = con.prepareStatement(DELETE_ROW_SQL);
+			stmt.setString(1, shortUrl);
+			stmt.execute();
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+}