| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.nifi.util.db; |
| |
| import static org.junit.Assert.assertEquals; |
| |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.sql.Connection; |
| import java.sql.DriverManager; |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.sql.Statement; |
| import java.util.Random; |
| |
| import org.apache.avro.file.DataFileStream; |
| import org.apache.avro.generic.GenericDatumReader; |
| import org.apache.avro.generic.GenericRecord; |
| import org.apache.avro.io.DatumReader; |
| import org.junit.BeforeClass; |
| import org.junit.Rule; |
| import org.junit.Test; |
| import org.junit.rules.TemporaryFolder; |
| |
| /** |
| * Test streaming using large number of result set rows. 1. Read data from |
| * database. 2. Create Avro schema from ResultSet meta data. 3. Read rows from |
| * ResultSet and write rows to Avro writer stream (Avro will create record for |
| * each row). 4. And finally read records from Avro stream to verify all data is |
| * present in Avro stream. |
| * |
| * |
| * Sql query will return all combinations from 3 table. For example when each |
| * table contain 1000 rows, result set will be 1 000 000 000 rows. |
| * |
| */ |
| public class TestJdbcHugeStream { |
| |
| @Rule |
| public TemporaryFolder folder = new TemporaryFolder(); |
| |
| @BeforeClass |
| public static void setup() { |
| System.setProperty("derby.stream.error.file", "target/derby.log"); |
| } |
| |
| @Test |
| public void readSend2StreamHuge_FileBased() throws ClassNotFoundException, SQLException, IOException { |
| |
| // remove previous test database, if any |
| folder.delete(); |
| |
| try (final Connection con = createConnection(folder.getRoot().getAbsolutePath())) { |
| loadTestData2Database(con, 100, 100, 100); |
| |
| try (final Statement st = con.createStatement()) { |
| // Notice! |
| // Following select is deliberately invalid! |
| // For testing we need huge amount of rows, so where part is not |
| // used. |
| final ResultSet resultSet = st.executeQuery("select " |
| + " PER.ID as PersonId, PER.NAME as PersonName, PER.CODE as PersonCode" |
| + ", PRD.ID as ProductId,PRD.NAME as ProductName,PRD.CODE as ProductCode" |
| + ", REL.ID as RelId, REL.NAME as RelName, REL.CODE as RelCode" |
| + ", ROW_NUMBER() OVER () as rownr " |
| + " from persons PER, products PRD, relationships REL"); |
| |
| final OutputStream outStream = new FileOutputStream("target/data.avro"); |
| final long nrOfRows = JdbcCommon.convertToAvroStream(resultSet, outStream, false); |
| |
| // Deserialize bytes to records |
| final InputStream instream = new FileInputStream("target/data.avro"); |
| |
| final DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(); |
| try (final DataFileStream<GenericRecord> dataFileReader = new DataFileStream<>(instream, datumReader)) { |
| GenericRecord record = null; |
| long recordsFromStream = 0; |
| while (dataFileReader.hasNext()) { |
| // Reuse record object by passing it to next(). This |
| // saves us from |
| // allocating and garbage collecting many objects for |
| // files with many items. |
| record = dataFileReader.next(record); |
| recordsFromStream += 1; |
| } |
| System.out.println("total nr of records from stream: " + recordsFromStream); |
| assertEquals(nrOfRows, recordsFromStream); |
| } |
| } |
| } |
| } |
| |
| // ================================================ helpers |
| // =============================================== |
| |
| static String dropPersons = "drop table persons"; |
| static String dropProducts = "drop table products"; |
| static String dropRelationships = "drop table relationships"; |
| static String createPersons = "create table persons (id integer, name varchar(100), code integer)"; |
| static String createProducts = "create table products (id integer, name varchar(100), code integer)"; |
| static String createRelationships = "create table relationships (id integer,name varchar(100), code integer)"; |
| |
| static public void loadTestData2Database(Connection con, int nrOfPersons, int nrOfProducts, int nrOfRels) throws ClassNotFoundException, SQLException { |
| |
| System.out.println(createRandomName()); |
| System.out.println(createRandomName()); |
| System.out.println(createRandomName()); |
| |
| final Statement st = con.createStatement(); |
| |
| // tables may not exist, this is not serious problem. |
| try { |
| st.executeUpdate(dropPersons); |
| } catch (final Exception ignored) { |
| } |
| |
| try { |
| st.executeUpdate(dropProducts); |
| } catch (final Exception ignored) { |
| } |
| |
| try { |
| st.executeUpdate(dropRelationships); |
| } catch (final Exception ignored) { |
| } |
| |
| st.executeUpdate(createPersons); |
| st.executeUpdate(createProducts); |
| st.executeUpdate(createRelationships); |
| |
| for (int i = 0; i < nrOfPersons; i++) |
| loadPersons(st, i); |
| |
| for (int i = 0; i < nrOfProducts; i++) |
| loadProducts(st, i); |
| |
| for (int i = 0; i < nrOfRels; i++) |
| loadRelationships(st, i); |
| |
| st.close(); |
| } |
| |
| static Random rng = new Random(53495); |
| |
| static private void loadPersons(Statement st, int nr) throws SQLException { |
| st.executeUpdate("insert into persons values (" + nr + ", '" + createRandomName() + "', " + rng.nextInt(469946) + ")"); |
| } |
| |
| static private void loadProducts(Statement st, int nr) throws SQLException { |
| st.executeUpdate("insert into products values (" + nr + ", '" + createRandomName() + "', " + rng.nextInt(469946) + ")"); |
| } |
| |
| static private void loadRelationships(Statement st, int nr) throws SQLException { |
| st.executeUpdate("insert into relationships values (" + nr + ", '" + createRandomName() + "', " + rng.nextInt(469946) + ")"); |
| } |
| |
| static private String createRandomName() { |
| return createRandomString() + " " + createRandomString(); |
| } |
| |
| static private String createRandomString() { |
| |
| final int length = rng.nextInt(10); |
| final String characters = "ABCDEFGHIJ"; |
| |
| final char[] text = new char[length]; |
| for (int i = 0; i < length; i++) { |
| text[i] = characters.charAt(rng.nextInt(characters.length())); |
| } |
| return new String(text); |
| } |
| |
| private Connection createConnection(String location) throws ClassNotFoundException, SQLException { |
| Class.forName("org.apache.derby.jdbc.EmbeddedDriver"); |
| return DriverManager.getConnection("jdbc:derby:" + location + ";create=true"); |
| } |
| |
| } |