Hide classes that really should not be public from the public API.

build/checkstyle.xml

@@ -42,7 +42,7 @@
   </module>
 
   <module name="TreeWalker">
-
+    <module name="SuppressionCommentFilter"/>
     <module name="PackageDeclaration"/>
     <module name="UpperEll"/>
     <module name="ArrayTypeStyle"/>

enterprise/backup/src/main/java/org/neo4j/backup/OnlineBackupCommandBuilder.java

@@ -26,7 +26,6 @@
 import java.io.OutputStream;
 import java.io.Writer;
 import java.nio.file.Path;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -42,15 +41,13 @@
 import org.neo4j.io.fs.DefaultFileSystemAbstraction;
 import org.neo4j.kernel.configuration.Config;
 
-import static java.lang.String.format;
-
 /**
  * This class encapsulates the information needed to perform an online backup against a running Neo4j instance
  * configured to act as a backup server.
  * <p>
  * All backup methods return the same instance, allowing for chaining calls.
  */
-public class OnlineBackupCommandBuilder
+class OnlineBackupCommandBuilder
 {
     private String host;
     private Integer port;

enterprise/backup/src/main/java/org/neo4j/backup/OnlineBackupCommandProvider.java

@@ -35,12 +35,17 @@
 import static java.lang.String.format;
 import static org.neo4j.backup.BackupSupportingClassesFactoryProvider.getProvidersByPriority;
 
-public class OnlineBackupCommandProvider extends AdminCommand.Provider
+class OnlineBackupCommandProvider extends AdminCommand.Provider
 {
+    // CHECKSTYLE:OFF
+    // Checkstyle complains that the `public` modifier is redundant since this class is package private.
+    // However, what Checkstyle doesn't know, is that this class is service loaded, and this *requires*
+    // a public no-arg constructor to work.
     public OnlineBackupCommandProvider()
     {
         super( "backup" );
     }
+    // CHECKSTYLE:ON
 
     @Override
     @Nonnull

enterprise/backup/src/main/java/org/neo4j/backup/ParametrisedOutsideWorld.java

@@ -32,15 +32,15 @@
 /**
  * An outside world where you can pick and choose which input/output are dummies.
  */
-public class ParametrisedOutsideWorld implements OutsideWorld
+class ParametrisedOutsideWorld implements OutsideWorld
 {
 
     private final PrintStream stdout;
     private final PrintStream stderr;
     private final Console stdin;
     private final FileSystemAbstraction fileSystemAbstraction;
 
-    public ParametrisedOutsideWorld( StringBuilder stdout, StringBuilder stderr )
+    ParametrisedOutsideWorld( StringBuilder stdout, StringBuilder stderr )
     {
         this( System.console(), streamFromBuilder( stdout ), streamFromBuilder( stderr ), new DefaultFileSystemAbstraction() );
     }
@@ -57,15 +57,15 @@ public void write( int i ) throws IOException
         };
     }
 
-    public ParametrisedOutsideWorld( Console stdin, OutputStream stdout, OutputStream stderr, FileSystemAbstraction fileSystemAbstraction )
+    ParametrisedOutsideWorld( Console stdin, OutputStream stdout, OutputStream stderr, FileSystemAbstraction fileSystemAbstraction )
     {
         this.stdout = new PrintStream( stdout );
         this.stderr = new PrintStream( stderr );
         this.fileSystemAbstraction = fileSystemAbstraction;
         this.stdin = stdin;
     }
 
-    public ParametrisedOutsideWorld( PrintStream stdout, PrintStream stderr )
+    ParametrisedOutsideWorld( PrintStream stdout, PrintStream stderr )
     {
         this( System.console(), stdout, stderr, new DefaultFileSystemAbstraction() );
     }

enterprise/backup/src/main/java/org/neo4j/backup/StoreCopyResponsePacker.java

@@ -45,14 +45,14 @@
  * Full backup will stream at most N transactions back, even if nothing happened during the backup.
  * Streaming these transaction aren't as important, since they are mostly a nice-to-have.
  */
-public class StoreCopyResponsePacker extends ResponsePacker
+class StoreCopyResponsePacker extends ResponsePacker
 {
     private final long mandatoryStartTransactionId;
     private final LogFileInformation logFileInformation;
     private final TransactionIdStore transactionIdStore;
     private final Monitor monitor;
 
-    public StoreCopyResponsePacker( LogicalTransactionStore transactionStore,
+    StoreCopyResponsePacker( LogicalTransactionStore transactionStore,
             TransactionIdStore transactionIdStore, LogFileInformation logFileInformation,
             Supplier<StoreId> storeId, long mandatoryStartTransactionId, StoreCopyServer.Monitor monitor )
     {