Resolve some TODOs, change null return based logic to exception based

src/main/java/me/bearns/fias/config/ApplicationConfig.java

@@ -1,5 +1,6 @@
 package me.bearns.fias.config;
 
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -21,6 +22,7 @@ import javax.sql.DataSource;
 @EnableJpaRepositories("me.bearns.fias.repository")
 @EnableTransactionManagement
 //@PropertySource(value = "application-{profile}.properties", ignoreResourceNotFound = true)
+@Slf4j
 class ApplicationConfig {
 
     @Autowired
@@ -43,7 +45,10 @@ class ApplicationConfig {
 
         HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
         vendorAdapter.setGenerateDdl(false); //use liquibase
-        vendorAdapter.setShowSql(true); //TODO Debug
+        if(log.isDebugEnabled()) {
+            log.debug("Enable SQL echo.");
+            vendorAdapter.setShowSql(true);
+        }
 
         LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
         factory.setJpaVendorAdapter(vendorAdapter);

src/main/java/me/bearns/fias/exceptions/RemoteAPIException.java

@@ -0,0 +1,11 @@
+package me.bearns.fias.exceptions;
+
+public class RemoteAPIException extends CommonException{
+    public RemoteAPIException(Exception e) {
+        super(e);
+    }
+
+    public RemoteAPIException(String s) {
+        super(s);
+    }
+}

src/main/java/me/bearns/fias/helpers/UpdaterImpl.java

@@ -105,7 +105,6 @@ public class UpdaterImpl implements UpdateHelper {
     }
 
     private void processArchive(File file, Predicate filter) throws CommonException {
-        //TODO
 
         try(final ZipFile zipFile = new ZipFile(file)){
 

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

@@ -1,14 +1,17 @@
 package me.bearns.fias.service;
 
 import me.bearns.fias.domain.FiasVersion;
+import me.bearns.fias.exceptions.RemoteAPIException;
 
 import java.util.List;
 
 public interface OnlineVersion {
 
-    long getLastVersionId();
+    long getLastVersionId() throws RemoteAPIException;
 
-    List<FiasVersion> getVersionsAfter(long version);
+    @lombok.NonNull
+    List<FiasVersion> getVersionsAfter(long version) throws RemoteAPIException;
 
-    List<FiasVersion> getLastVersion();
+    @lombok.NonNull
+    List<FiasVersion> getLastVersion() throws RemoteAPIException;
 }

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

@@ -2,7 +2,9 @@ package me.bearns.fias.service;
 
 import lombok.AllArgsConstructor;
 import me.bearns.fias.domain.FiasVersion;
+import me.bearns.fias.exceptions.RemoteAPIException;
 import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
 
 import java.util.ArrayList;
@@ -20,33 +22,45 @@ public class OnlineVersionImpl implements OnlineVersion{
     RestTemplate client = new RestTemplate();
 
     @Override
-    public long getLastVersionId() {
+    public long getLastVersionId() throws RemoteAPIException {
 
-        final FiasVersion version = client.getForObject(GET_LAST_FILE_INFO, FiasVersion.class);
+        final FiasVersion version = request(GET_LAST_FILE_INFO, FiasVersion.class);
 
-        if(version != null) return version.getVersionId();
-
-        return 0; //todo
+        return version.getVersionId();
     }
 
     @Override
-    public List<FiasVersion> getVersionsAfter(long version) {
+    public List<FiasVersion> getVersionsAfter(long version) throws RemoteAPIException {
 
-        final FiasVersion[] versions = client.getForObject(GET_ALL_FILE_INFO, FiasVersion[].class);
+         final FiasVersion[] versions = request(GET_ALL_FILE_INFO, FiasVersion[].class);
 
-        if(versions != null) {
          return Arrays.stream(versions).filter(v -> v.getVersionId() > version).collect(Collectors.toList());
     }
 
-        return null; //todo
-    }
-
     @Override
-    public List<FiasVersion> getLastVersion() {
+    public List<FiasVersion> getLastVersion() throws RemoteAPIException {
+
         List<FiasVersion> versions = new ArrayList<>();
 
-        versions.add(client.getForObject(GET_LAST_FILE_INFO, FiasVersion.class));
+        final FiasVersion lastFile = request(GET_LAST_FILE_INFO, FiasVersion.class);
 
-        return versions; //todo
+        versions.add(lastFile);
+
+        return versions;
+    }
+
+    private <T> T request(final String url, Class<T> responseType) throws RemoteAPIException {
+
+        try {
+
+            final T result = client.getForObject(url, responseType);
+
+            if (result == null) throw new RemoteAPIException("Request to " + url + " return no data.");
+
+            return result;
+
+        } catch (RestClientException e){
+            throw new RemoteAPIException(e);
+        }
     }
 }