Update the "shared" module with checkstyle checks.

Remove extra callback class that composed two existing callbacks.

checkstyle.xml

@@ -128,6 +128,13 @@
             <!--<property name="tokens" value="LOR, LAND"/>--> <!-- TODO: uncomment -->
             <property name="tokens" value="EQUAL, NOT_EQUAL"/>
         </module>
+
+<!--        <module name="EmptyLineSeparator">-->
+<!--            <property name="allowNoEmptyLineBetweenFields" value="false"/>-->
+<!--            <property name="allowMultipleEmptyLines" value="false" />-->
+<!--            <property name="allowMultipleEmptyLinesInsideClassMembers" value="false"/>-->
+<!--        </module>-->
+
     </module>
 
 </module>

data-migration/src/main/java/com/quorum/tessera/data/migration/JdbcDataExporter.java

@@ -1,5 +1,8 @@
 package com.quorum.tessera.data.migration;
 
+import com.quorum.tessera.io.IOCallback;
+import com.quorum.tessera.nio.unix.UriCallback;
+
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -18,9 +21,11 @@ public class JdbcDataExporter implements DataExporter {
     private final List<String> createTables;
 
     public JdbcDataExporter(String jdbcUrl, String insertRow, URL ddl) {
+        final Path uri = UriCallback.execute(() -> Paths.get(ddl.toURI()));
+
         this.jdbcUrl = jdbcUrl;
         this.insertRow = insertRow;
-        this.createTables = UriCallback.execute(() -> Files.readAllLines(Paths.get(ddl.toURI())));
+        this.createTables = IOCallback.execute(() -> Files.readAllLines(uri));
     }
 
     @Override

shared/src/main/java/com/quorum/tessera/ServiceLoaderUtil.java

@@ -7,10 +7,12 @@
 public interface ServiceLoaderUtil {
 
     static <T> Optional<T> load(Class<T> type) {
-        Iterator<T> it = ServiceLoader.load(type).iterator();
+        final Iterator<T> it = ServiceLoader.load(type).iterator();
+
         if (it.hasNext()) {
             return Optional.of(it.next());
         }
+
         return Optional.empty();
     }
 

shared/src/main/java/com/quorum/tessera/io/FilesDelegate.java

@@ -10,6 +10,7 @@
 import java.nio.file.attribute.PosixFilePermission;
 import java.util.Set;
 import java.util.stream.Stream;
+
 /**
  * <p>
  *  Delegates calls to nio Files functions unchecking IOExceptions
@@ -28,7 +29,6 @@ default boolean deleteIfExists(Path path) {
         return IOCallback.execute(() -> Files.deleteIfExists(path));
     }
 
-
     default Path createFile(Path path, FileAttribute... attributes) {
 
         return IOCallback.execute(() -> Files.createFile(path, attributes));

shared/src/main/java/com/quorum/tessera/io/NoopSystemAdapter.java

@@ -28,6 +28,6 @@ public void write(int b) throws IOException {
             });
         }
 
-    };
+    }
 
 }

shared/src/main/java/com/quorum/tessera/io/SystemAdapter.java

@@ -1,12 +1,12 @@
 package com.quorum.tessera.io;
 
 import com.quorum.tessera.ServiceLoaderUtil;
+
 import java.io.PrintStream;
 
 public interface SystemAdapter {
-
-    SystemAdapter INSTANCE = ServiceLoaderUtil.load(SystemAdapter.class)
-                .orElse(new SystemAdapter() {
+
+    SystemAdapter INSTANCE = ServiceLoaderUtil.load(SystemAdapter.class).orElse(new SystemAdapter() {
     });
 
     default PrintStream out() {

shared/src/main/java/com/quorum/tessera/jaxb/JaxbCallback.java

@@ -1,22 +1,19 @@
-
 package com.quorum.tessera.jaxb;
 
 import javax.xml.bind.DataBindingException;
 import javax.xml.bind.JAXBException;
 
 @FunctionalInterface
 public interface JaxbCallback<T> {
-
-
-    T doExecute() throws JAXBException,DataBindingException;
-
-
+
+    T doExecute() throws JAXBException, DataBindingException;
+
     static <T> T execute(JaxbCallback<T> callback) {
         try {
             return callback.doExecute();
         } catch (JAXBException ex) {
             throw new DataBindingException(ex);
         }
     }
-    
+
 }

shared/src/main/java/com/quorum/tessera/nio/unix/UnixSocketFileSystemProvider.java

@@ -7,15 +7,7 @@
 import java.nio.channels.AsynchronousFileChannel;
 import java.nio.channels.FileChannel;
 import java.nio.channels.SeekableByteChannel;
-import java.nio.file.AccessMode;
-import java.nio.file.CopyOption;
-import java.nio.file.DirectoryStream;
-import java.nio.file.FileStore;
-import java.nio.file.FileSystem;
-import java.nio.file.FileSystems;
-import java.nio.file.LinkOption;
-import java.nio.file.OpenOption;
-import java.nio.file.Path;
+import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.FileAttribute;
 import java.nio.file.attribute.FileAttributeView;
@@ -26,7 +18,6 @@
 
 /**
  * Implementation of FileSystemProvider that handles URIs with unix scheme
- *
  */
 public class UnixSocketFileSystemProvider extends FileSystemProvider {
 
@@ -45,10 +36,18 @@ public String getScheme() {
         return "unix";
     }
 
-    private static URI convert(URI uri) {
-        return UriCallback.execute(() -> {
-            return new URI("file",uri.getUserInfo(),uri.getHost(),uri.getPort(),uri.getPath(),uri.getQuery(),uri.getFragment());
-        });
+    private static URI convert(final URI uri) {
+        return UriCallback.execute(
+            () -> new URI(
+                "file",
+                uri.getUserInfo(),
+                uri.getHost(),
+                uri.getPort(),
+                uri.getPath(),
+                uri.getQuery(),
+                uri.getFragment()
+            )
+        );
 
     }
 

shared/src/main/java/com/quorum/tessera/nio/unix/UriCallback.java

@@ -4,7 +4,6 @@
 import java.io.UncheckedIOException;
 import java.net.URISyntaxException;
 
-
 public interface UriCallback<T> {
 
     T doExecute() throws URISyntaxException;
@@ -16,4 +15,5 @@ static <T> T execute(UriCallback<T> callback) {
              throw new UncheckedIOException(new IOException(ex));
         }
     }
+
 }

shared/src/main/java/com/quorum/tessera/reflect/ReflectException.java

@@ -1,7 +1,5 @@
-
 package com.quorum.tessera.reflect;
 
-
 public class ReflectException extends RuntimeException {
 
     public ReflectException(Throwable cause) {

shared/src/main/java/com/quorum/tessera/service/Service.java

@@ -3,8 +3,7 @@
 public interface Service {
 
     enum Status {
-        STARTED,
-        STOPPED
+        STARTED, STOPPED
     }
 
     void start();

shared/src/main/java/com/quorum/tessera/service/ServiceContainer.java

@@ -1,34 +1,36 @@
 package com.quorum.tessera.service;
 
 import com.quorum.tessera.service.Service.Status;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
 import java.util.Optional;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
-import javax.annotation.PostConstruct;
-import javax.annotation.PreDestroy;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class ServiceContainer implements Runnable {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(ServiceContainer.class);
 
-    private Service service;
+    private final Service service;
 
-    private ScheduledExecutorService executorService;
+    private final ScheduledExecutorService executorService;
 
-    private long initialDelay;
+    private final long initialDelay;
 
-    private long period;
+    private final long period;
 
-    public ServiceContainer(Service service) {
+    public ServiceContainer(final Service service) {
         this(service, Executors.newScheduledThreadPool(1), 1000L, 1000L);
     }
 
-    public ServiceContainer(Service service,
-            ScheduledExecutorService executorService,
-            long initialDelay, long period) {
+    public ServiceContainer(final Service service,
+                            final ScheduledExecutorService executorService,
+                            final long initialDelay,
+                            final long period) {
         this.service = service;
         this.executorService = executorService;
         this.initialDelay = initialDelay;
@@ -48,22 +50,21 @@ public void stop() {
 
     @Override
     public void run() {
-        LOGGER.trace("Check status {}",service);
+        LOGGER.trace("Check status {}", service);
         Status status = service.status();
-        LOGGER.trace("{} Status is {}",service,status);
+        LOGGER.trace("{} Status is {}", service, status);
 
         if (status == Service.Status.STOPPED) {
-            LOGGER.warn("Service {} not stopped attempt to restart.",service);
+            LOGGER.warn("Service {} not stopped attempt to restart.", service);
             try {
-                LOGGER.debug("Starting service {}",service);
+                LOGGER.debug("Starting service {}", service);
                 service.start();
-                LOGGER.debug("Started service {}",service);
+                LOGGER.debug("Started service {}", service);
             } catch (Throwable ex) {
                 LOGGER.trace(null, ex);
-                LOGGER.warn("Exception thrown : {} While starting service {}",
-                        Optional.ofNullable(ex.getCause()).orElse(ex).getMessage(),service);
+                LOGGER.warn("Exception thrown : {} While starting service {}", Optional.ofNullable(ex.getCause()).orElse(ex).getMessage(), service);
             }
         }
     }
-    
+
 }

shared/src/test/java/com/acme/DefaultTestService.java

@@ -0,0 +1,8 @@
+package com.acme;
+
+/**
+ * An implementation of {@link TestService} that can be loaded by the Java
+ * Service Loader
+ */
+public class DefaultTestService implements TestService {
+}

shared/src/test/java/com/acme/TestService.java

@@ -0,0 +1,8 @@
+package com.acme;
+
+/**
+ * An interface for testing the Service loader. See
+ * {@link com.quorum.tessera.ServiceLoaderUtilTest}.
+ */
+public interface TestService {
+}