/*
* Copyright 2013 NGDATA nv
*
* Licensed 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 com.ngdata.hbaseindexer.cli;
import com.google.common.collect.Lists;
import joptsimple.OptionParser;
import joptsimple.OptionException;
import joptsimple.OptionSet;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.LogManager;
import org.apache.log4j.PropertyConfigurator;
import java.io.IOException;
import java.io.InputStream;
import java.util.regex.Pattern;
/**
* Provides a basic framework for the various CLI tools.
*
* <p>Implementations can implement or override the following methods:</p>
*
* <ul>
* <li>{@link #setupOptionParser()}</li>
* <li>{@link #getCmdName()}</li>
* <li>{@link #run(OptionSet)}</li>
* <li>{@link #cleanup()}</li>
* </ul>
*
* <p>Implementations should call the {@link #run(String[])} method from their "public static void main".</p>
*/
public abstract class BaseCli {
public void run(String[] args) throws Exception {
OptionParser parser = setupOptionParser();
OptionSet options = null;
try {
options = parser.parse(args);
} catch (OptionException e) {
System.out.println("Error parsing command line options:");
System.out.println(e.getMessage());
printHelp(parser);
System.exit(1);
}
if (options.has("h")) {
printHelp(parser);
System.exit(1);
}
if (!options.has("default-log")) {
LogManager.resetConfiguration();
PropertyConfigurator.configure(BaseCli.class.getResource("cli-log4j.properties"));
}
try {
run(options);
} catch (CliException e) {
System.err.println();
System.err.println(e.getMessage());
System.exit(e.getExitCode());
} catch (Exception e) {
System.err.println();
e.printStackTrace(System.err);
System.exit(1);
} finally {
try {
cleanup();
} catch (Throwable t) {
System.err.println("Error during cleanup:");
t.printStackTrace();
}
}
}
/**
* Optionally override this to add CLI options. The canonical usage is to first call super,
* and then add your own options to it.
*/
protected OptionParser setupOptionParser() {
OptionParser parser = new OptionParser();
parser.acceptsAll(Lists.newArrayList("h", "help"), "shows help for this command");
parser.acceptsAll(Lists.newArrayList("dl", "default-log"), "don't override log4j config");
return parser;
}
/**
* The name of this command, for use in informational messages.
*/
protected abstract String getCmdName();
/**
* Any cleanup that should be done. Called from a finally block around the {@link #run(OptionSet)} method.
*/
protected void cleanup() {
}
/**
* This method is where the actual work should be done. The canonical usage is to first call
* super.
*/
protected abstract void run(OptionSet options) throws Exception;
protected void printHelp(OptionParser parser) throws IOException {
printHelpHeader();
parser.printHelpOn(System.out);
printHelpFooter();
}
protected void printHelpHeader() throws IOException {
String className = getClass().getName();
String helpHeaderPath = className.replaceAll(Pattern.quote("."), "/") + "_help_header.txt";
InputStream is = getClass().getClassLoader().getResourceAsStream(helpHeaderPath);
if (is != null) {
IOUtils.copy(is, System.out);
System.out.println();
System.out.println();
}
}
protected void printHelpFooter() throws IOException {
String className = getClass().getName();
String helpHeaderPath = className.replaceAll(Pattern.quote("."), "/") + "_help_footer.txt";
InputStream is = getClass().getClassLoader().getResourceAsStream(helpHeaderPath);
if (is != null) {
System.out.println();
IOUtils.copy(is, System.out);
System.out.println();
}
}
}