GH-3205: Make HadoopPositionOutputStream.close() safe to call even if closed (#3206)

Author: dominicso

parquet-hadoop/src/main/java/org/apache/parquet/hadoop/util/HadoopPositionOutputStream.java

@@ -20,11 +20,13 @@
 package org.apache.parquet.hadoop.util;
 
 import java.io.IOException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.parquet.io.PositionOutputStream;
 
 public class HadoopPositionOutputStream extends PositionOutputStream {
   private final FSDataOutputStream wrapped;
+  private final AtomicBoolean closed = new AtomicBoolean(false);
 
   HadoopPositionOutputStream(FSDataOutputStream wrapped) {
     this.wrapped = wrapped;
@@ -61,6 +63,9 @@ public void flush() throws IOException {
 
   @Override
   public void close() throws IOException {
+    if (closed.getAndSet(true)) {
+      return;
+    }
     try (FSDataOutputStream fdos = wrapped) {
       fdos.flush();
     }