org.apache.flink.table.client.util.ClientWrapperClassLoader 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.flink.table.client.util;
import org.apache.flink.annotation.Experimental;
import org.apache.flink.annotation.Internal;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.util.FlinkUserCodeClassLoader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static org.apache.flink.util.FlinkUserCodeClassLoaders.SafetyNetWrapperClassLoader;
/**
* This class loader extends {@link SafetyNetWrapperClassLoader}, upon the {@code addURL} method, it
* also exposes a {@code removeURL} method which used to remove unnecessary jar from current
* classloader path. This class loader wraps a {@link FlinkUserCodeClassLoader} and an old
* classloader list, the class load is delegated to the inner {@link FlinkUserCodeClassLoader}.
*
* This is only used to SqlClient for supporting {@code REMOVE JAR} clause currently. When remove
* a jar, get the registered jar url list from current {@link FlinkUserCodeClassLoader} firstly,
* then create a new instance of {@link FlinkUserCodeClassLoader} which urls doesn't include the
* removed jar, and the currentClassLoader point to new instance object, the old object is added to
* list to be closed when close {@link ClientWrapperClassLoader}.
*
*
Note: This classloader is not guaranteed to actually remove class or resource, any classes or
* resources in the removed jar that are already loaded, are still accessible.
*/
@Experimental
@Internal
public class ClientWrapperClassLoader extends SafetyNetWrapperClassLoader {
private static final Logger LOG = LoggerFactory.getLogger(ClientWrapperClassLoader.class);
static {
ClassLoader.registerAsParallelCapable();
}
private final Configuration configuration;
private final List originClassLoaders;
public ClientWrapperClassLoader(FlinkUserCodeClassLoader inner, Configuration configuration) {
super(inner, inner.getParent());
this.configuration = new Configuration(configuration);
this.originClassLoaders = new ArrayList<>();
}
public void removeURL(URL url) {
Set registeredUrls = Stream.of(inner.getURLs()).collect(Collectors.toSet());
if (!registeredUrls.contains(url)) {
LOG.warn(
String.format(
"Could not remove the specified jar because the jar path [%s] is not found in classloader.",
url));
return;
}
originClassLoaders.add(inner);
// build a new classloader without removed jars
registeredUrls.remove(url);
inner =
ClientClassloaderUtil.buildUserClassLoader(
new ArrayList<>(registeredUrls),
ClientWrapperClassLoader.class.getClassLoader(),
configuration);
}
@Override
public void close() {
super.close();
// close other classloader in the list
for (FlinkUserCodeClassLoader classLoader : originClassLoaders) {
try {
classLoader.close();
} catch (IOException e) {
LOG.error("Failed to close the origin classloader.", e);
}
}
originClassLoaders.clear();
}
}