Java tutorial
/* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.prestosql.plugin.jdbc; import com.google.common.base.VerifyException; import com.google.common.collect.ImmutableList; import io.airlift.slice.Slice; import io.prestosql.spi.Page; import io.prestosql.spi.PrestoException; import io.prestosql.spi.block.Block; import io.prestosql.spi.connector.ConnectorPageSink; import io.prestosql.spi.type.Type; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.SQLException; import java.sql.SQLNonTransientException; import java.util.Collection; import java.util.List; import java.util.concurrent.CompletableFuture; import static com.google.common.base.Verify.verify; import static com.google.common.collect.ImmutableList.toImmutableList; import static io.prestosql.plugin.jdbc.JdbcErrorCode.JDBC_ERROR; import static io.prestosql.plugin.jdbc.JdbcErrorCode.JDBC_NON_TRANSIENT_ERROR; import static java.lang.String.format; import static java.util.concurrent.CompletableFuture.completedFuture; public class JdbcPageSink implements ConnectorPageSink { private final Connection connection; private final PreparedStatement statement; private final List<Type> columnTypes; private final List<WriteFunction> columnWriters; private int batchSize; public JdbcPageSink(JdbcOutputTableHandle handle, JdbcClient jdbcClient) { try { connection = jdbcClient.getConnection(handle); } catch (SQLException e) { throw new PrestoException(JDBC_ERROR, e); } try { connection.setAutoCommit(false); statement = connection.prepareStatement(jdbcClient.buildInsertSql(handle)); } catch (SQLException e) { closeWithSuppression(connection, e); throw new PrestoException(JDBC_ERROR, e); } columnTypes = handle.getColumnTypes(); columnWriters = columnTypes.stream().map(type -> { WriteFunction writeFunction = jdbcClient.toWriteMapping(type).getWriteFunction(); verify(type.getJavaType() == writeFunction.getJavaType(), "Presto type %s is not compatible with write function %s accepting %s", type, writeFunction, writeFunction.getJavaType()); return writeFunction; }).collect(toImmutableList()); } @Override public CompletableFuture<?> appendPage(Page page) { try { for (int position = 0; position < page.getPositionCount(); position++) { for (int channel = 0; channel < page.getChannelCount(); channel++) { appendColumn(page, position, channel); } statement.addBatch(); batchSize++; if (batchSize >= 1000) { statement.executeBatch(); connection.commit(); connection.setAutoCommit(false); batchSize = 0; } } } catch (SQLException e) { throw new PrestoException(JDBC_ERROR, e); } return NOT_BLOCKED; } private void appendColumn(Page page, int position, int channel) throws SQLException { Block block = page.getBlock(channel); int parameterIndex = channel + 1; if (block.isNull(position)) { statement.setObject(parameterIndex, null); return; } Type type = columnTypes.get(channel); Class<?> javaType = type.getJavaType(); WriteFunction writeFunction = columnWriters.get(channel); if (javaType == boolean.class) { ((BooleanWriteFunction) writeFunction).set(statement, parameterIndex, type.getBoolean(block, position)); } else if (javaType == long.class) { ((LongWriteFunction) writeFunction).set(statement, parameterIndex, type.getLong(block, position)); } else if (javaType == double.class) { ((DoubleWriteFunction) writeFunction).set(statement, parameterIndex, type.getDouble(block, position)); } else if (javaType == Slice.class) { ((SliceWriteFunction) writeFunction).set(statement, parameterIndex, type.getSlice(block, position)); } else { throw new VerifyException(format("Unexpected type %s with java type %s", type, javaType.getName())); } } @Override public CompletableFuture<Collection<Slice>> finish() { // commit and close try (Connection connection = this.connection; PreparedStatement statement = this.statement) { if (batchSize > 0) { statement.executeBatch(); connection.commit(); } } catch (SQLNonTransientException e) { throw new PrestoException(JDBC_NON_TRANSIENT_ERROR, e); } catch (SQLException e) { throw new PrestoException(JDBC_ERROR, e); } // the committer does not need any additional info return completedFuture(ImmutableList.of()); } @SuppressWarnings("unused") @Override public void abort() { // rollback and close try (Connection connection = this.connection; PreparedStatement statement = this.statement) { connection.rollback(); } catch (SQLException e) { throw new PrestoException(JDBC_ERROR, e); } } @SuppressWarnings("ObjectEquality") private static void closeWithSuppression(Connection connection, Throwable throwable) { try { connection.close(); } catch (Throwable t) { // Self-suppression not permitted if (throwable != t) { throwable.addSuppressed(t); } } } }