org.springframework.core.env.SimpleCommandLineArgsParser Maven / Gradle / Ivy
/*
* Copyright 2002-2020 the original author or authors.
*
* 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
*
* https://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.springframework.core.env;
/**
* Parses a {@code String[]} of command line arguments in order to populate a
* {@link CommandLineArgs} object.
*
* Working with option arguments
* Option arguments must adhere to the exact syntax:
*
*
--optName[=optValue]
*
* That is, options must be prefixed with "{@code --}" and may or may not
* specify a value. If a value is specified, the name and value must be separated
* without spaces by an equals sign ("="). The value may optionally be
* an empty string.
*
*
Valid examples of option arguments
*
* --foo
* --foo=
* --foo=""
* --foo=bar
* --foo="bar then baz"
* --foo=bar,baz,biz
*
* Invalid examples of option arguments
*
* -foo
* --foo bar
* --foo = bar
* --foo=bar --foo=baz --foo=biz
*
* Working with non-option arguments
* Any and all arguments specified at the command line without the "{@code --}"
* option prefix will be considered as "non-option arguments" and made available
* through the {@link CommandLineArgs#getNonOptionArgs()} method.
*
* @author Chris Beams
* @author Sam Brannen
* @since 3.1
*/
class SimpleCommandLineArgsParser {
/**
* Parse the given {@code String} array based on the rules described {@linkplain
* SimpleCommandLineArgsParser above}, returning a fully-populated
* {@link CommandLineArgs} object.
* @param args command line arguments, typically from a {@code main()} method
*/
public CommandLineArgs parse(String... args) {
CommandLineArgs commandLineArgs = new CommandLineArgs();
for (String arg : args) {
if (arg.startsWith("--")) {
String optionText = arg.substring(2);
String optionName;
String optionValue = null;
int indexOfEqualsSign = optionText.indexOf('=');
if (indexOfEqualsSign > -1) {
optionName = optionText.substring(0, indexOfEqualsSign);
optionValue = optionText.substring(indexOfEqualsSign + 1);
}
else {
optionName = optionText;
}
if (optionName.isEmpty()) {
throw new IllegalArgumentException("Invalid argument syntax: " + arg);
}
commandLineArgs.addOptionArg(optionName, optionValue);
}
else {
commandLineArgs.addNonOptionArg(arg);
}
}
return commandLineArgs;
}
}