ceph/src/arrow/java/adapter/jdbc/src/main/java/org/apache/arrow/adapter/jdbc/consumer/BlobConsumer.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  *    http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 package org.apache.arrow.adapter.jdbc.consumer;
  19
  20 import java.io.IOException;
  21 import java.sql.Blob;
  22 import java.sql.ResultSet;
  23 import java.sql.SQLException;
  24
  25 import org.apache.arrow.vector.VarBinaryVector;
  26
  27 /**
  28  * Consumer which consume blob type values from {@link ResultSet}.
  29  * Write the data to {@link VarBinaryVector}.
  30  */
  31 public class BlobConsumer extends BaseConsumer<VarBinaryVector> {
  32
  33   private BinaryConsumer delegate;
  34
  35   private final boolean nullable;
  36
  37   /**
  38    * Creates a consumer for {@link VarBinaryVector}.
  39    */
  40   public static BlobConsumer createConsumer(
  41           BinaryConsumer delegate, int index, boolean nullable) {
  42     return new BlobConsumer(delegate, index, nullable);
  43   }
  44
  45   /**
  46    * Instantiate a BlobConsumer.
  47    */
  48   public BlobConsumer(BinaryConsumer delegate, int index, boolean nullable) {
  49     super(null, index);
  50     this.delegate = delegate;
  51     this.nullable = nullable;
  52   }
  53
  54   @Override
  55   public void consume(ResultSet resultSet) throws SQLException, IOException {
  56     Blob blob = resultSet.getBlob(columnIndexInResultSet);
  57     if (blob != null) {
  58       delegate.consume(blob.getBinaryStream());
  59     }
  60     delegate.moveWriterPosition();
  61   }
  62
  63   @Override
  64   public void close() throws Exception {
  65     delegate.close();
  66   }
  67
  68   @Override
  69   public void resetValueVector(VarBinaryVector vector) {
  70     delegate = BinaryConsumer.createConsumer(vector, columnIndexInResultSet, nullable);
  71   }
  72 }