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.raptor.legacy.systemtables; import com.google.common.base.VerifyException; import com.google.common.collect.ImmutableList; import io.airlift.slice.Slice; import io.prestosql.spi.type.Type; import java.sql.ResultSet; import java.sql.SQLException; import java.util.List; import java.util.Set; import static com.google.common.base.Preconditions.checkArgument; import static io.airlift.slice.SizeOf.SIZE_OF_BYTE; import static io.airlift.slice.SizeOf.SIZE_OF_DOUBLE; import static io.airlift.slice.SizeOf.SIZE_OF_LONG; import static io.airlift.slice.Slices.wrappedBuffer; import static io.prestosql.plugin.raptor.legacy.util.UuidUtil.uuidFromBytes; import static java.lang.String.format; import static java.util.Locale.ENGLISH; import static java.util.Objects.requireNonNull; public class ResultSetValues { private final boolean[] booleans; private final long[] longs; private final double[] doubles; private final String[] strings; private final boolean[] nulls; private final List<Type> types; public ResultSetValues(List<Type> types) { this.types = ImmutableList.copyOf(requireNonNull(types, "types is null")); this.booleans = new boolean[types.size()]; this.longs = new long[types.size()]; this.doubles = new double[types.size()]; this.strings = new String[types.size()]; this.nulls = new boolean[types.size()]; } int extractValues(ResultSet resultSet, Set<Integer> uuidColumns, Set<Integer> hexColumns) throws SQLException { checkArgument(resultSet != null, "resultSet is null"); int completedBytes = 0; for (int i = 0; i < types.size(); i++) { Class<?> javaType = types.get(i).getJavaType(); if (javaType == boolean.class) { booleans[i] = resultSet.getBoolean(i + 1); nulls[i] = resultSet.wasNull(); if (!nulls[i]) { completedBytes += SIZE_OF_BYTE; } } else if (javaType == long.class) { longs[i] = resultSet.getLong(i + 1); nulls[i] = resultSet.wasNull(); if (!nulls[i]) { completedBytes += SIZE_OF_LONG; } } else if (javaType == double.class) { doubles[i] = resultSet.getDouble(i + 1); nulls[i] = resultSet.wasNull(); if (!nulls[i]) { completedBytes += SIZE_OF_DOUBLE; } } else if (javaType == Slice.class) { if (uuidColumns.contains(i)) { byte[] bytes = resultSet.getBytes(i + 1); nulls[i] = resultSet.wasNull(); strings[i] = nulls[i] ? null : uuidFromBytes(bytes).toString().toLowerCase(ENGLISH); } else if (hexColumns.contains(i)) { long value = resultSet.getLong(i + 1); nulls[i] = resultSet.wasNull(); strings[i] = nulls[i] ? null : format("%016x", value); } else { String value = resultSet.getString(i + 1); nulls[i] = resultSet.wasNull(); strings[i] = nulls[i] ? null : value; } if (!nulls[i]) { completedBytes += strings[i].length(); } } else { throw new VerifyException("Unknown Java type: " + javaType); } } return completedBytes; } public boolean getBoolean(int field) { return booleans[field]; } public long getLong(int field) { return longs[field]; } public double getDouble(int field) { return doubles[field]; } public Slice getSlice(int field) { return wrappedBuffer(strings[field].getBytes()); } public boolean isNull(int field) { return nulls[field]; } }