Added S3 sink configuration documentation. (#555)

Closes #515 
 
* Added Scale class to present file sizes and memory sizes in human
readable form.
 * fixed validators to show correct information.
* Updated the S3SinkConfigDef so that it contains all the
S3SinkConfiguration definition informtion.
 * Removed S3Sink configuration information out of S3SinkConfig

Author: Claudenw

commons/src/main/java/io/aiven/commons/collections/TimeScale.java

@@ -33,9 +33,11 @@ public enum TimeScale {
         public String format(final long milliseconds) {
             return String.format("%s %s", milliseconds, unitName());
         }
-    },
-    SECONDS(MILLISECONDS.milliseconds * 1000), MINUTES(SECONDS.milliseconds * 60), HOURS(
-            MINUTES.milliseconds * 60), DAYS(HOURS.milliseconds * 24);
+    }, //
+    SECONDS(MILLISECONDS.milliseconds * 1000), //
+    MINUTES(SECONDS.milliseconds * 60), //
+    HOURS(MINUTES.milliseconds * 60), //
+    DAYS(HOURS.milliseconds * 24);
 
     /**
      * The Decimal format for the TimeUnit displays.

commons/src/main/java/io/aiven/kafka/connect/common/config/CommonConfig.java

@@ -175,13 +175,14 @@ final Collection<ConfigValue> multiValidateValues(final Map<String, String> prop
         }
 
         @Override
+        @SuppressWarnings("PMD.AvoidCatchingGenericException")
         public final List<ConfigValue> validate(final Map<String, String> props) {
             final Map<String, ConfigValue> valueMap = validateAll(props);
 
             try {
                 return new ArrayList<>(multiValidate(valueMap).values());
-            } catch (RuntimeException e) { // NOPMD AvoidCatchingGenericException
-                // any exceptions thrown in the above block are accounted for in the super.validate(props) call.
+            } catch (RuntimeException e) {
+                // any exceptions thrown in the above block are accounted for in the validateAll(props) call.
                 return new ArrayList<>(valueMap.values());
             }
         }

commons/src/main/java/io/aiven/kafka/connect/common/config/FileNameFragment.java

@@ -58,9 +58,9 @@ public final class FileNameFragment extends ConfigFragment {
     @VisibleForTesting
     static final String FILE_MAX_RECORDS = "file.max.records";
     @VisibleForTesting
-    static final String FILE_NAME_TIMESTAMP_TIMEZONE = "file.name.timestamp.timezone";
+    public static final String FILE_NAME_TIMESTAMP_TIMEZONE = "file.name.timestamp.timezone";
     @VisibleForTesting
-    static final String FILE_NAME_TIMESTAMP_SOURCE = "file.name.timestamp.source";
+    public static final String FILE_NAME_TIMESTAMP_SOURCE = "file.name.timestamp.source";
     @VisibleForTesting
     public static final String FILE_NAME_TEMPLATE_CONFIG = "file.name.template";
     @VisibleForTesting

commons/src/main/java/io/aiven/kafka/connect/common/config/OutputFormatFragment.java

@@ -32,7 +32,7 @@
  */
 public final class OutputFormatFragment extends ConfigFragment {
     @VisibleForTesting
-    static final String GROUP_FORMAT = "Format";
+    public static final String GROUP_NAME = "Format";
     @VisibleForTesting
     static public final String FORMAT_OUTPUT_FIELDS_CONFIG = "format.output.fields";
     @VisibleForTesting
@@ -90,25 +90,25 @@ public static int update(final ConfigDef configDef, final OutputFieldType defaul
         int formatGroupCounter = 0;
 
         configDef.define(FORMAT_OUTPUT_TYPE_CONFIG, ConfigDef.Type.STRING, FormatType.CSV.name, OUTPUT_TYPE_VALIDATOR,
-                ConfigDef.Importance.MEDIUM, "The format type of output content.", GROUP_FORMAT, ++formatGroupCounter,
+                ConfigDef.Importance.MEDIUM, "The format type of output content.", GROUP_NAME, ++formatGroupCounter,
                 ConfigDef.Width.NONE, FORMAT_OUTPUT_TYPE_CONFIG,
                 FixedSetRecommender.ofSupportedValues(FormatType.names()));
 
         configDef.define(FORMAT_OUTPUT_FIELDS_CONFIG, ConfigDef.Type.LIST,
                 Objects.isNull(defaultFieldType) ? null : defaultFieldType.name, // NOPMD NullAssignment
-                OUTPUT_FIELDS_VALIDATOR, ConfigDef.Importance.MEDIUM, "Fields to put into output files.", GROUP_FORMAT,
+                OUTPUT_FIELDS_VALIDATOR, ConfigDef.Importance.MEDIUM, "Fields to put into output files.", GROUP_NAME,
                 ++formatGroupCounter, ConfigDef.Width.NONE, FORMAT_OUTPUT_FIELDS_CONFIG,
                 FixedSetRecommender.ofSupportedValues(OutputFieldType.names()));
 
         configDef.define(FORMAT_OUTPUT_FIELDS_VALUE_ENCODING_CONFIG, ConfigDef.Type.STRING,
                 OutputFieldEncodingType.BASE64.name, OUTPUT_FIELDS_ENCODING_VALIDATOR, ConfigDef.Importance.MEDIUM,
                 "The type of encoding for the value field. " + "The supported values are: "
                         + OutputFieldEncodingType.SUPPORTED_FIELD_ENCODING_TYPES + ".",
-                GROUP_FORMAT, ++formatGroupCounter, ConfigDef.Width.NONE, FORMAT_OUTPUT_FIELDS_VALUE_ENCODING_CONFIG,
+                GROUP_NAME, ++formatGroupCounter, ConfigDef.Width.NONE, FORMAT_OUTPUT_FIELDS_VALUE_ENCODING_CONFIG,
                 FixedSetRecommender.ofSupportedValues(OutputFieldEncodingType.names()));
 
         configDef.define(FORMAT_OUTPUT_ENVELOPE_CONFIG, ConfigDef.Type.BOOLEAN, true, ConfigDef.Importance.MEDIUM,
-                "Whether to enable envelope for entries with single field.", GROUP_FORMAT, ++formatGroupCounter,
+                "Whether to enable envelope for entries with single field.", GROUP_NAME, ++formatGroupCounter,
                 ConfigDef.Width.SHORT, FORMAT_OUTPUT_ENVELOPE_CONFIG);
         return formatGroupCounter;
     }

commons/src/main/java/io/aiven/kafka/connect/common/config/validators/OutputFieldsValidator.java

@@ -44,4 +44,9 @@ public void ensureValid(final String name, final Object value) {
         }
     }
 
+    @Override
+    public String toString() {
+        return OutputField.SUPPORTED_OUTPUT_FIELDS;
+    }
+
 }

commons/src/testFixtures/java/io/aiven/kafka/connect/common/config/OutputFormatFragmentFixture.java

@@ -19,7 +19,7 @@
 public class OutputFormatFragmentFixture {// NOPMD
 
     public enum OutputFormatArgs {
-        GROUP_FORMAT(OutputFormatFragment.GROUP_FORMAT), FORMAT_OUTPUT_FIELDS_CONFIG(
+        GROUP_FORMAT(OutputFormatFragment.GROUP_NAME), FORMAT_OUTPUT_FIELDS_CONFIG(
                 OutputFormatFragment.FORMAT_OUTPUT_FIELDS_CONFIG), FORMAT_OUTPUT_FIELDS_VALUE_ENCODING_CONFIG(
                         OutputFormatFragment.FORMAT_OUTPUT_FIELDS_VALUE_ENCODING_CONFIG), FORMAT_OUTPUT_ENVELOPE_CONFIG(
                                 OutputFormatFragment.FORMAT_OUTPUT_ENVELOPE_CONFIG), FORMAT_OUTPUT_TYPE_CONFIG(