Keep old ProtoRecordConverter constructor as deprecated

Author: qinghui-xu

parquet-protobuf/src/main/java/org/apache/parquet/proto/ProtoMessageConverter.java

@@ -65,7 +65,16 @@ class ProtoMessageConverter extends GroupConverter {
   protected final Message.Builder myBuilder;
   protected final Map<String, String> extraMetadata;
 
-  // used in record converter
+  /**
+   * Used in record converter.
+   *
+   * @param conf Configuration for some customizable behavior,
+   *            eg. "parquet.proto.accept.unknown.enum" - whether to accept an unparsable (after trying with proto enum label and number) enum as `UNKNOWN` with a number -1 (the one generated automatically for each proto enum)
+   * @param pvc The parent value containing the converted proto
+   * @param protoClass The class of the converted proto
+   * @param parquetSchema The (part of) parquet schema that should match to the expected proto
+   * @param extraMetadata Metadata from parquet footer, containing useful information about parquet-proto convertion behavior
+   */
   ProtoMessageConverter(Configuration conf, ParentValueContainer pvc, Class<? extends Message> protoClass, GroupType parquetSchema, Map<String, String> extraMetadata) {
     this(conf, pvc, Protobufs.getMessageBuilder(protoClass), parquetSchema, extraMetadata);
   }

parquet-protobuf/src/main/java/org/apache/parquet/proto/ProtoRecordConverter.java

@@ -24,6 +24,7 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.parquet.schema.MessageType;
 
+import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -58,6 +59,18 @@ public ProtoRecordConverter(Configuration conf, Message.Builder builder, Message
     reusedBuilder = getBuilder();
   }
 
+  // Old version constructors, kept for code backward compatibility.
+  // The instance will not be able to handle unknowned enum values written by parquet-proto (the behavior before PARQUET-1455)
+  @Deprecated
+  public ProtoRecordConverter(Class<? extends Message> protoclass, MessageType parquetSchema) {
+    this(new Configuration(), protoclass, parquetSchema, Collections.emptyMap());
+  }
+
+  @Deprecated
+  public ProtoRecordConverter(Message.Builder builder, MessageType parquetSchema) {
+    this(new Configuration(), builder, parquetSchema, Collections.emptyMap());
+  }
+
   @Override
   public void start() {
     reusedBuilder.clear();