org.apache.kafka.common.config.AbstractConfig 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.kafka.common.config;
import org.apache.kafka.common.Configurable;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.config.types.Password;
import org.apache.kafka.common.utils.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* A convenient base class for configurations to extend.
*
* This class holds both the original configuration that was provided as well as the parsed
*/
public class AbstractConfig {
private final Logger log = LoggerFactory.getLogger(getClass());
/* configs for which values have been requested, used to detect unused configs */
private final Set used;
/* the original values passed in by the user */
private final Map originals;
/* the parsed values */
private final Map values;
@SuppressWarnings("unchecked")
public AbstractConfig(ConfigDef definition, Map originals, boolean doLog) {
/* check that all the keys are really strings */
for (Object key : originals.keySet())
if (!(key instanceof String))
throw new ConfigException(key.toString(), originals.get(key), "Key must be a string.");
this.originals = (Map) originals;
this.values = definition.parse(this.originals);
this.used = Collections.synchronizedSet(new HashSet());
if (doLog)
logAll();
}
public AbstractConfig(ConfigDef definition, Map originals) {
this(definition, originals, true);
}
public AbstractConfig(Map parsedConfig) {
this.values = parsedConfig;
this.originals = new HashMap<>();
this.used = Collections.synchronizedSet(new HashSet());
}
protected Object get(String key) {
if (!values.containsKey(key))
throw new ConfigException(String.format("Unknown configuration '%s'", key));
used.add(key);
return values.get(key);
}
public void ignore(String key) {
used.add(key);
}
public Short getShort(String key) {
return (Short) get(key);
}
public Integer getInt(String key) {
return (Integer) get(key);
}
public Long getLong(String key) {
return (Long) get(key);
}
public Double getDouble(String key) {
return (Double) get(key);
}
@SuppressWarnings("unchecked")
public List getList(String key) {
return (List) get(key);
}
public Boolean getBoolean(String key) {
return (Boolean) get(key);
}
public String getString(String key) {
return (String) get(key);
}
public Password getPassword(String key) {
return (Password) get(key);
}
public Class getClass(String key) {
return (Class) get(key);
}
public Set unused() {
Set keys = new HashSet<>(originals.keySet());
keys.removeAll(used);
return keys;
}
public Map originals() {
Map copy = new RecordingMap<>();
copy.putAll(originals);
return copy;
}
/**
* Get all the original settings, ensuring that all values are of type String.
* @return the original settings
* @throws ClassCastException if any of the values are not strings
*/
public Map originalsStrings() {
Map copy = new RecordingMap<>();
for (Map.Entry entry : originals.entrySet()) {
if (!(entry.getValue() instanceof String))
throw new ClassCastException("Non-string value found in original settings for key " + entry.getKey() +
": " + (entry.getValue() == null ? null : entry.getValue().getClass().getName()));
copy.put(entry.getKey(), (String) entry.getValue());
}
return copy;
}
/**
* Gets all original settings with the given prefix, stripping the prefix before adding it to the output.
*
* @param prefix the prefix to use as a filter
* @return a Map containing the settings with the prefix
*/
public Map originalsWithPrefix(String prefix) {
Map result = new RecordingMap<>();
for (Map.Entry entry : originals.entrySet()) {
if (entry.getKey().startsWith(prefix) && entry.getKey().length() > prefix.length())
result.put(entry.getKey().substring(prefix.length()), entry.getValue());
}
return result;
}
public Map values() {
return new RecordingMap<>(values);
}
private void logAll() {
StringBuilder b = new StringBuilder();
b.append(getClass().getSimpleName());
b.append(" values: ");
b.append(Utils.NL);
for (Map.Entry entry : this.values.entrySet()) {
b.append('\t');
b.append(entry.getKey());
b.append(" = ");
b.append(entry.getValue());
b.append(Utils.NL);
}
log.info(b.toString());
}
/**
* Log warnings for any unused configurations
*/
public void logUnused() {
for (String key : unused())
log.warn("The configuration {} = {} was supplied but isn't a known config.", key, this.originals.get(key));
}
/**
* Get a configured instance of the give class specified by the given configuration key. If the object implements
* Configurable configure it using the configuration.
*
* @param key The configuration key for the class
* @param t The interface the class should implement
* @return A configured instance of the class
*/
public T getConfiguredInstance(String key, Class t) {
Class c = getClass(key);
if (c == null)
return null;
Object o = Utils.newInstance(c);
if (!t.isInstance(o))
throw new KafkaException(c.getName() + " is not an instance of " + t.getName());
if (o instanceof Configurable)
((Configurable) o).configure(this.originals);
return t.cast(o);
}
/**
* Get a list of configured instances of the given class specified by the given configuration key. The configuration
* may specify either null or an empty string to indicate no configured instances. In both cases, this method
* returns an empty list to indicate no configured instances.
* @param key The configuration key for the class
* @param t The interface the class should implement
* @return The list of configured instances
*/
public List getConfiguredInstances(String key, Class t) {
List klasses = getList(key);
List objects = new ArrayList();
if (klasses == null)
return objects;
for (String klass : klasses) {
Object o;
try {
o = Utils.newInstance(klass, t);
} catch (ClassNotFoundException e) {
throw new KafkaException(klass + " ClassNotFoundException exception occured", e);
}
if (!t.isInstance(o))
throw new KafkaException(klass + " is not an instance of " + t.getName());
if (o instanceof Configurable)
((Configurable) o).configure(this.originals);
objects.add(t.cast(o));
}
return objects;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
AbstractConfig that = (AbstractConfig) o;
return originals.equals(that.originals);
}
@Override
public int hashCode() {
return originals.hashCode();
}
/**
* Marks keys retrieved via `get` as used. This is needed because `Configurable.configure` takes a `Map` instead
* of an `AbstractConfig` and we can't change that without breaking public API like `Partitioner`.
*/
private class RecordingMap extends HashMap {
RecordingMap() {}
RecordingMap(Map m) {
super(m);
}
@Override
public V get(Object key) {
if (key instanceof String)
ignore((String) key);
return super.get(key);
}
}
}