# Spring SimpleCommandLineArgsParser

- Author: [HuiFer](https://github.com/huifer)
- 源码阅读仓库: [SourceHot-spring](https://github.com/SourceHot/spring-framework-read)

- 类全路径: `org.springframework.core.env.SimpleCommandLineArgsParser
- 类作用: 将命令行参数解析成 `org.springframework.core.env.CommandLineArgs`

- 完整代码如下.

```java

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, arg.length());
				String optionName;
				String optionValue = null;
				if (optionText.contains("=")) {
					optionName = optionText.substring(0, optionText.indexOf('='));
					optionValue = optionText.substring(optionText.indexOf('=') + 1, optionText.length());
				}
				else {
					optionName = optionText;
				}
				if (optionName.isEmpty() || (optionValue != null && optionValue.isEmpty())) {
					throw new IllegalArgumentException("Invalid argument syntax: " + arg);
				}
				commandLineArgs.addOptionArg(optionName, optionValue);
			}
			else {
				commandLineArgs.addNonOptionArg(arg);
			}
		}
		return commandLineArgs;
	}

}

```

- 处理流程
  1. 循环命令行参数列表
  2. 去掉 `--` 和 `=` 获取参数名称和参数值放入结果集合