flink源码分析 - 命令行参数解析-CommandLineParser
flink版本: flink-1.11.2
调用位置:
org.apache.flink.runtime.entrypoint.StandaloneSessionClusterEntrypoint#main
代码位置:
flink核心命令行解析器:
org.apache.flink.runtime.entrypoint.parser.CommandLineParser
/*
* 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.runtime.entrypoint.parser;
import org.apache.flink.runtime.entrypoint.FlinkParseException;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import javax.annotation.Nonnull;
/**
* Command line parser which produces a result from the given
* command line arguments.
*/
public class CommandLineParser {
@Nonnull
private final ParserResultFactory parserResultFactory;
public CommandLineParser(@Nonnull ParserResultFactory parserResultFactory) {
// TODO_MA 注释： parserResultFactory = EntrypointClusterConfigurationParserFactory
this.parserResultFactory = parserResultFactory;
}
public T parse(@Nonnull String[] args) throws FlinkParseException {
final DefaultParser parser = new DefaultParser();
final Options options = parserResultFactory.getOptions();
final CommandLine commandLine;
try {
/*************************************************
* TODO_MA 马中华 https://blog.csdn.net/zhongqi2513
* 注释： 解析参数
*/
commandLine = parser.parse(options, args, true);
} catch (ParseException e) {
throw new FlinkParseException("Failed to parse the command line arguments.", e);
}
// TODO_MA 注释： 创建 EntrypointClusterConfiguration 返回
return parserResultFactory.createResult(commandLine);
}
public void printHelp(@Nonnull String cmdLineSyntax) {
final HelpFormatter helpFormatter = new HelpFormatter();
helpFormatter.setLeftPadding(5);
helpFormatter.setWidth(80);
helpFormatter.printHelp(cmdLineSyntax, parserResultFactory.getOptions(), true);
}
}
其中核心方法是构造方法及parse方法。
构造方法主要用于从外界获取parserResultFactory变量，用于后期解析；
parse(@Nonnull String[] args) 方法用于解析参数。 其中args即为从外部命令行传入的参数。
解析过程中用到的核心对象是
final DefaultParser parser = new DefaultParser();
该对象来源于 Apache Common Cli包，具体用法参考（内部包含官方文档地址）:
使用Apache commons-cli包进行命令行参数解析的示例代码-CSDN博客
核心解析步骤是:
commandLine = parser.parse(options, args, true); 以及
return parserResultFactory.createResult(commandLine);。
其中parser对象进行参数解析。 parserResultFactory主要为parser对象提供需要解析的命令行选项options，及通过 parserResultFactory.createResult(commandLine) 从parser的解析结果commandLine中拿到命令行选项对应值，并构造出相应结果。
ParserResultFactory的接口定义:
/*
* 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.runtime.entrypoint.parser;
import org.apache.flink.runtime.entrypoint.FlinkParseException;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Options;
import javax.annotation.Nonnull;
/**
* Parser result factory used by the {@link CommandLineParser}.
*
* @param type of the parsed result
*/
public interface ParserResultFactory {
/**
* Returns all relevant {@link Options} for parsing the command line
* arguments.
*
* @return Options to use for the parsing
*/
Options getOptions();
/**
* Create the result of the command line argument parsing.
*
* @param commandLine to extract the options from
* @return Result of the parsing
* @throws FlinkParseException Thrown on failures while parsing command line arguments
*/
T createResult(@Nonnull CommandLine commandLine) throws FlinkParseException;
}
其下具体实现类如图所示:
截取两个具体实现供参考:
ClusterConfigurationParserFactory:
/*
* 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.runtime.entrypoint;
import org.apache.flink.runtime.entrypoint.parser.ParserResultFactory;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Options;
import javax.annotation.Nonnull;
import java.util.Properties;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.CONFIG_DIR_OPTION;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.DYNAMIC_PROPERTY_OPTION;
/**
* Parser factory which generates a {@link ClusterConfiguration} from the given
* list of command line arguments.
*/
public class ClusterConfigurationParserFactory implements ParserResultFactory {
public static Options options() {
final Options options = new Options();
options.addOption(CONFIG_DIR_OPTION);
options.addOption(DYNAMIC_PROPERTY_OPTION);
return options;
}
@Override
public Options getOptions() {
return options();
}
@Override
public ClusterConfiguration createResult(@Nonnull CommandLine commandLine) {
final String configDir = commandLine.getOptionValue(CONFIG_DIR_OPTION.getOpt());
final Properties dynamicProperties = commandLine.getOptionProperties(DYNAMIC_PROPERTY_OPTION.getOpt());
return new ClusterConfiguration(configDir, dynamicProperties, commandLine.getArgs());
}
}
EntrypointClusterConfigurationParserFactory：
/*
* 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.runtime.entrypoint;
import org.apache.flink.runtime.entrypoint.parser.ParserResultFactory;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Options;
import javax.annotation.Nonnull;
import java.util.Properties;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.CONFIG_DIR_OPTION;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.DYNAMIC_PROPERTY_OPTION;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.EXECUTION_MODE_OPTION;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.HOST_OPTION;
import static org.apache.flink.runtime.entrypoint.parser.CommandLineOptions.REST_PORT_OPTION;
/**
* Parser factory for {@link EntrypointClusterConfiguration}.
*/
public class EntrypointClusterConfigurationParserFactory implements ParserResultFactory {
@Override
public Options getOptions() {
final Options options = new Options();
options.addOption(CONFIG_DIR_OPTION);
options.addOption(REST_PORT_OPTION);
options.addOption(DYNAMIC_PROPERTY_OPTION);
options.addOption(HOST_OPTION);
options.addOption(EXECUTION_MODE_OPTION);
return options;
}
@Override
public EntrypointClusterConfiguration createResult(@Nonnull CommandLine commandLine) {
// TODO_MA 注释： 解析 --configDir -c
final String configDir = commandLine.getOptionValue(CONFIG_DIR_OPTION.getOpt());
// TODO_MA 注释： 解析程序的 -Dkey-value参数
final Properties dynamicProperties = commandLine.getOptionProperties(DYNAMIC_PROPERTY_OPTION.getOpt());
// TODO_MA 注释： 解析 --webui-port -r
final String restPortStr = commandLine.getOptionValue(REST_PORT_OPTION.getOpt(), "-1");
final int restPort = Integer.parseInt(restPortStr);
// TODO_MA 注释： 解析 --host -h
final String hostname = commandLine.getOptionValue(HOST_OPTION.getOpt());
/*************************************************
* TODO_MA 马中华 https://blog.csdn.net/zhongqi2513
* 注释： 返回一个 EntrypointClusterConfiguration 对象
*/
return new EntrypointClusterConfiguration(
configDir,
dynamicProperties,
commandLine.getArgs(),
hostname,
restPort);
}
}