Java tutorial
/* * 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.minifi.integration.util; import com.fasterxml.jackson.databind.ObjectMapper; import com.palantir.docker.compose.connection.Container; import com.palantir.docker.compose.connection.DockerPort; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.util.List; import java.util.Map; import java.util.regex.Pattern; import java.util.stream.Collectors; import static org.junit.Assert.fail; public class LogUtil { private static final Logger logger = LoggerFactory.getLogger(LogUtil.class); public static void verifyLogEntries(String expectedJsonFilename, Container container) throws Exception { List<ExpectedLogEntry> expectedLogEntries; try (InputStream inputStream = LogUtil.class.getClassLoader().getResourceAsStream(expectedJsonFilename)) { List<Map<String, Object>> expected = new ObjectMapper().readValue(inputStream, List.class); expectedLogEntries = expected.stream() .map(map -> new ExpectedLogEntry(Pattern.compile((String) map.get("pattern")), (int) map.getOrDefault("occurrences", 1))) .collect(Collectors.toList()); } DockerPort dockerPort = container.port(8000); URL url = new URL("http://" + dockerPort.getIp() + ":" + dockerPort.getExternalPort()); HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); try (InputStream inputStream = urlConnection.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream); BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) { String line; for (ExpectedLogEntry expectedLogEntry : expectedLogEntries) { boolean satisfied = false; int occurrences = 0; while ((line = bufferedReader.readLine()) != null) { if (expectedLogEntry.pattern.matcher(line).find()) { logger.info("Found expected: " + line); if (++occurrences >= expectedLogEntry.numOccurrences) { logger.info("Found target " + occurrences + " times"); satisfied = true; break; } } } if (!satisfied) { fail("End of log reached without " + expectedLogEntry.numOccurrences + " match(es) of " + expectedLogEntry.pattern); } } } finally { urlConnection.disconnect(); } } private static class ExpectedLogEntry { private final Pattern pattern; private final int numOccurrences; private ExpectedLogEntry(Pattern pattern, int numOccurrences) { this.pattern = pattern; this.numOccurrences = numOccurrences; } } }