Downloader implementation

src/main/java/me/bearns/fias/service/Downloader.java

@@ -0,0 +1,9 @@
+package me.bearns.fias.service;
+
+import java.io.InputStream;
+import java.util.concurrent.Future;
+
+public interface Downloader {
+
+    public Future<InputStream> download(String url);
+}

src/main/java/me/bearns/fias/service/DownloaderImpl.java

@@ -0,0 +1,28 @@
+package me.bearns.fias.service;
+
+import java.io.InputStream;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+public class DownloaderImpl implements Downloader {
+
+    private static final ExecutorService pool = Executors.newCachedThreadPool();
+
+    @Override
+    public Future<InputStream> download(String url) {
+
+        CompletableFuture<InputStream> completableFuture
+                = new CompletableFuture<>();
+
+        pool.submit(() -> {
+            InputStream is = null;
+            //todo
+
+            completableFuture.complete(is);
+        });
+
+        return completableFuture;
+    }
+}

src/main/java/me/bearns/fias/service/FiasUpdater.java

@@ -5,7 +5,10 @@ import me.bearns.fias.repository.FiasVersionRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+import java.io.InputStream;
 import java.util.List;
+import java.util.concurrent.Future;
+import java.util.stream.Stream;
 
 @Service
 public class FiasUpdater implements Updater {
@@ -14,7 +17,9 @@ public class FiasUpdater implements Updater {
     FiasVersionRepository versions;
 
     @Autowired
-    OnlineVersion downloadService;
+    OnlineVersion clientStub;
+    @Autowired
+    Downloader downloader;
 
     @Override
     public void update() {
@@ -26,12 +31,12 @@ public class FiasUpdater implements Updater {
 
             final Long dbVersion = dbVersionObj.getVersionId();
 
-            final long lastOnlineVersion = downloadService.getLastVersionId();
+            final long lastOnlineVersion = clientStub.getLastVersionId();
 
             if(lastOnlineVersion > dbVersion) {
                 //need update
 
-                final List<FiasVersion> updates = downloadService.getVersionsAfter(dbVersion);
+                final List<FiasVersion> updates = clientStub.getVersionsAfter(dbVersion);
 
                 if(updates != null && !updates.isEmpty()) {
                     processUpdates(updates, false);
@@ -45,7 +50,7 @@ public class FiasUpdater implements Updater {
     @Override
     public void reload(Long... regions) {
 
-        final List<FiasVersion> lastVersion = downloadService.getLastVersion();
+        final List<FiasVersion> lastVersion = clientStub.getLastVersion();
         if(lastVersion != null) {
             processUpdates(lastVersion, true, regions);
         }
@@ -57,14 +62,9 @@ public class FiasUpdater implements Updater {
 
         updates.sort((o1, o2) -> Math.toIntExact(o1.getVersionId() - o2.getVersionId()));
 
-        //pre-fetch files if update multiple version
+        //just for test
+        final Stream<Future<InputStream>> stream = updates.stream().map(u -> downloader.download(reloadFlag ? u.getFiasCompleteXmlUrl() : u.getFiasDeltaXmlUrl()));
 
-        for (FiasVersion update : updates) {
-
-            final String url = reloadFlag ? update.getFiasCompleteXmlUrl() : update.getFiasDeltaXmlUrl();
-
-            //run update here
-        }
 
     }
 }