org.apache.nifi.lookup.SimpleCsvFileLookupService Maven / Gradle / Ivy
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* 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.lookup;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.locks.ReentrantLock;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVRecord;
import org.apache.commons.lang3.StringUtils;
import org.apache.nifi.annotation.documentation.CapabilityDescription;
import org.apache.nifi.annotation.documentation.Tags;
import org.apache.nifi.annotation.lifecycle.OnEnabled;
import org.apache.nifi.components.PropertyDescriptor;
import org.apache.nifi.controller.AbstractControllerService;
import org.apache.nifi.controller.ControllerServiceInitializationContext;
import org.apache.nifi.expression.ExpressionLanguageScope;
import org.apache.nifi.controller.ConfigurationContext;
import org.apache.nifi.logging.ComponentLog;
import org.apache.nifi.processor.util.StandardValidators;
import org.apache.nifi.reporting.InitializationException;
import org.apache.nifi.util.file.monitor.LastModifiedMonitor;
import org.apache.nifi.util.file.monitor.SynchronousFileWatcher;
@Tags({"lookup", "cache", "enrich", "join", "csv", "reloadable", "key", "value"})
@CapabilityDescription("A reloadable CSV file-based lookup service")
public class SimpleCsvFileLookupService extends AbstractControllerService implements StringLookupService {
private static final String KEY = "key";
private static final Set REQUIRED_KEYS = Collections.unmodifiableSet(Stream.of(KEY).collect(Collectors.toSet()));
public static final PropertyDescriptor CSV_FILE =
new PropertyDescriptor.Builder()
.name("csv-file")
.displayName("CSV File")
.description("A CSV file.")
.required(true)
.addValidator(StandardValidators.FILE_EXISTS_VALIDATOR)
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
.build();
static final PropertyDescriptor CSV_FORMAT = new PropertyDescriptor.Builder()
.name("CSV Format")
.description("Specifies which \"format\" the CSV data is in, or specifies if custom formatting should be used.")
.expressionLanguageSupported(ExpressionLanguageScope.NONE)
.allowableValues(Arrays.asList(CSVFormat.Predefined.values()).stream().map(e -> e.toString()).collect(Collectors.toSet()))
.defaultValue(CSVFormat.Predefined.Default.toString())
.required(true)
.build();
public static final PropertyDescriptor CHARSET =
new PropertyDescriptor.Builder()
.name("Character Set")
.description("The Character Encoding that is used to decode the CSV file.")
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
.addValidator(StandardValidators.CHARACTER_SET_VALIDATOR)
.defaultValue("UTF-8")
.required(true)
.build();
public static final PropertyDescriptor LOOKUP_KEY_COLUMN =
new PropertyDescriptor.Builder()
.name("lookup-key-column")
.displayName("Lookup Key Column")
.description("Lookup key column.")
.required(true)
.addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
.build();
public static final PropertyDescriptor LOOKUP_VALUE_COLUMN =
new PropertyDescriptor.Builder()
.name("lookup-value-column")
.displayName("Lookup Value Column")
.description("Lookup value column.")
.required(true)
.addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
.build();
public static final PropertyDescriptor IGNORE_DUPLICATES =
new PropertyDescriptor.Builder()
.name("ignore-duplicates")
.displayName("Ignore Duplicates")
.description("Ignore duplicate keys for records in the CSV file.")
.addValidator(StandardValidators.BOOLEAN_VALIDATOR)
.allowableValues("true", "false")
.defaultValue("true")
.required(true)
.build();
private List properties;
private volatile ConcurrentMap cache;
private volatile String csvFile;
private volatile CSVFormat csvFormat;
private volatile String charset;
private volatile String lookupKeyColumn;
private volatile String lookupValueColumn;
private volatile boolean ignoreDuplicates;
private volatile SynchronousFileWatcher watcher;
private final ReentrantLock lock = new ReentrantLock();
private void loadCache() throws IllegalStateException, IOException {
if (lock.tryLock()) {
try {
final ComponentLog logger = getLogger();
if (logger.isDebugEnabled()) {
logger.debug("Loading lookup table from file: " + csvFile);
}
final Map properties = new HashMap<>();
try (final InputStream is = new FileInputStream(csvFile)) {
try (final InputStreamReader reader = new InputStreamReader(is, charset)) {
final Iterable records = csvFormat.withFirstRecordAsHeader().parse(reader);
for (final CSVRecord record : records) {
final String key = record.get(lookupKeyColumn);
final String value = record.get(lookupValueColumn);
if (StringUtils.isBlank(key)) {
throw new IllegalStateException("Empty lookup key encountered in: " + csvFile);
} else if (!ignoreDuplicates && properties.containsKey(key)) {
throw new IllegalStateException("Duplicate lookup key encountered: " + key + " in " + csvFile);
} else if (ignoreDuplicates && properties.containsKey(key)) {
logger.warn("Duplicate lookup key encountered: {} in {}", new Object[]{key, csvFile});
}
properties.put(key, value);
}
}
}
this.cache = new ConcurrentHashMap<>(properties);
if (cache.isEmpty()) {
logger.warn("Lookup table is empty after reading file: " + csvFile);
}
} finally {
lock.unlock();
}
}
}
@Override
protected List getSupportedPropertyDescriptors() {
return properties;
}
@Override
protected void init(final ControllerServiceInitializationContext context) throws InitializationException {
final List properties = new ArrayList<>();
properties.add(CSV_FILE);
properties.add(CSV_FORMAT);
properties.add(CHARSET);
properties.add(LOOKUP_KEY_COLUMN);
properties.add(LOOKUP_VALUE_COLUMN);
properties.add(IGNORE_DUPLICATES);
this.properties = Collections.unmodifiableList(properties);
}
@OnEnabled
public void onEnabled(final ConfigurationContext context) throws InitializationException, IOException, FileNotFoundException {
this.csvFile = context.getProperty(CSV_FILE).evaluateAttributeExpressions().getValue();
this.csvFormat = CSVFormat.Predefined.valueOf(context.getProperty(CSV_FORMAT).getValue()).getFormat();
this.charset = context.getProperty(CHARSET).evaluateAttributeExpressions().getValue();
this.lookupKeyColumn = context.getProperty(LOOKUP_KEY_COLUMN).evaluateAttributeExpressions().getValue();
this.lookupValueColumn = context.getProperty(LOOKUP_VALUE_COLUMN).evaluateAttributeExpressions().getValue();
this.ignoreDuplicates = context.getProperty(IGNORE_DUPLICATES).asBoolean();
this.watcher = new SynchronousFileWatcher(Paths.get(csvFile), new LastModifiedMonitor(), 30000L);
try {
loadCache();
} catch (final IllegalStateException e) {
throw new InitializationException(e.getMessage(), e);
}
}
@Override
public Optional lookup(final Map coordinates) throws LookupFailureException {
if (coordinates == null) {
return Optional.empty();
}
final String key = coordinates.get(KEY).toString();
if (StringUtils.isBlank(key)) {
return Optional.empty();
}
try {
if (watcher != null && watcher.checkAndReset()) {
loadCache();
}
} catch (final IllegalStateException | IOException e) {
throw new LookupFailureException(e.getMessage(), e);
}
return Optional.ofNullable(cache.get(key));
}
@Override
public Set getRequiredKeys() {
return REQUIRED_KEYS;
}
}