Avoid duplication of code

src/clientP2P/ClientP2P.java

@@ -1,45 +1,22 @@
 package clientP2P;
 import java.io.File;
 import clientP2P.ClientManagementUDP;
+import tools.Directories;
 
 public class ClientP2P {
 	private String host;
 	private int port;
-	private String directory;
+	private String dataHomeDirectory;
 	public ClientP2P() {
 		host = "localhost";
 		port = 40000;
-		String d;
-		/* Follow XDG Base Directory Specification
-		 * https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
-		 */
-		if (System.getProperty("os.name").equals("Linux")) {
-			d = System.getenv().get("XDG_DATA_HOME");
-			if (d == null || d.equals("")) {
-				d = System.getenv().get("HOME");
-				if (d != null && (!d.equals(""))) {
-					d += "/.local/share";
-				} else {
-					d += ".";
-				}
-			}
-		} else if (os.equals("Mac")||os.equals("Mac OS X") {
-			/* Apple MacOS X User Data Directory
-			 * https://developer.apple.com/library/archive/qa/qa1170/_index.html */
-			d = System.getProperty("user.home") + "/Library";
-		}  else {
-			d = ".";
-		}
-		d += "/P2P_JAVA_PROJECT_CLIENT/";
-		// create directory if not already exists
-		new File(d).mkdirs();
-		directory = d;
-		System.out.println("Client will try to contact server at " + host + " on port " + port + ". It will save files in " + directory); 
+		dataHomeDirectory = new Directories("P2P_JAVA_PROJECT_CLIENT").getDataHomeDirectory();
+		System.out.println("Client will try to contact server at " + host + " on port " + port + ". It will save files in " + dataHomeDirectory); 
 	}
 
 	public static void main(String [] args) {
 		ClientP2P c = new ClientP2P();
-		ClientManagementUDP cm = new ClientManagementUDP(c.directory, c.host, c.port);
+		ClientManagementUDP cm = new ClientManagementUDP(c.dataHomeDirectory, c.host, c.port);
 		Thread t = new Thread(cm);
 		t.setName("client P2P-JAVA-PROJECT");
 		t.start();

src/serverP2P/ServerP2P.java

@@ -1,43 +1,19 @@
 package serverP2P;
 import java.io.File;
 import serverP2P.ServerManagementUDP;
+import tools.Directories;
 
 public class ServerP2P {
 	private int port;
-	private String directory;
+	private String dataHomeDirectory;
 	public ServerP2P() {
 		port = 40000;
-		String d;
-		/* Follow XDG Base Directory Specification
-		 * https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
-		 */
-		String os = System.getProperty("os.name");
-		if (os.equals("Linux")) {
-			d = System.getenv().get("XDG_DATA_HOME");
-			if (d == null || d.equals("")) {
-				d = System.getenv().get("HOME");
-				if (d != null && (!d.equals(""))) {
-					d += "/.local/share";
-				} else {
-					d += ".";
-				}
-			}
-		} else if (os.equals("Mac")||os.equals("Mac OS X") {
-			/* Apple MacOS X User Data Directory
-			 * https://developer.apple.com/library/archive/qa/qa1170/_index.html */
-			d = System.getProperty("user.home") + "/Library";
-		} else {
-			d = ".";
-		}
-		d += "/P2P_JAVA_PROJECT_SERVER/";
-		// create directory if not already exists
-		new File(d).mkdirs();
-		directory = d;
-		System.out.println("Server will listen on port " + port + " and serve files from " + directory);
+		dataHomeDirectory = new Directories("P2P_JAVA_PROJECT_SERVER").getDataHomeDirectory();
+		System.out.println("Server will listen on port " + port + " and serve files from " + dataHomeDirectory);
 	}
 	public static void main(String [] args) {
 		ServerP2P s = new ServerP2P();
-		ServerManagementUDP sm = new ServerManagementUDP(s.directory, s.port);
+		ServerManagementUDP sm = new ServerManagementUDP(s.dataHomeDirectory, s.port);
 		Thread t = new Thread(sm);
 		t.setName("server P2P-JAVA-PROJECT");
 		t.start();

src/tools/Directories.java

@@ -0,0 +1,40 @@
+package tools;
+
+public class Directories {
+	private String projectName;
+	private String dataHomeDirectory;
+	
+	public Directories(String projectName) {
+		this.projectName = projectName;
+		setDataHomeDirectory();
+	}
+	private void setDataHomeDirectory() {
+		/* Follow XDG Base Directory Specification
+		 * https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+		 */
+		String os = System.getProperty("os.name");
+		if (os.equals("Linux")) {
+			d = System.getenv().get("XDG_DATA_HOME");
+			if (d == null || d.equals("")) {
+				d = System.getProperty("user.home") + "/.local/share";
+			}
+		} else if (os.equals("Mac")||os.equals("Mac OS X") {
+			/* Apple MacOS X User Data Directory
+			 * https://developer.apple.com/library/archive/qa/qa1170/_index.html */
+			d = System.getProperty("user.home") + "/Library";
+		} else {
+			d = ".";
+		}
+		d += "/" + projectName + "/";
+		// create directory if not already exists
+		new File(d).mkdirs();
+		dataHomeDirectory = d;
+	}
+
+	public String getDataHomeDirectory() {
+		return dataHomeDirectory();
+	}
+	
+	
+
+}