近期在用一些扩展或者类库的时候，偶尔会碰到使用Composer生成php包的问题。
总结步骤如下：
window下安装composer：参考
http://www.kankanews.com/ICkengine/archives/28197.shtml

下载：

Windows环境

Composer官方推荐使用安装包进行安装，据说下载Composer-Setup.exe这个即可用向导模式安装。

安装完毕后，使用命令行定位到需要生成代码的目录。
在目录下创建一个composer.json的文件。格式为：

{"require": {"guzzlehttp/guzzle": "~5.0","guzzlehttp/guzzle": "~5.0",}}

使用CMD的composer命令生成代码：
E:\DannyCode\composer>composer install
会生成如下的结果：
Loading composer repositories with package information
Installing dependencies (including require-dev)
- Installing react/promise (v2.0.0)
Loading from cache

- Installing guzzlehttp/streams (3.0.0)
Loading from cache

- Installing guzzlehttp/ringphp (1.0.0)
Loading from cache

- Installing guzzlehttp/guzzle (5.0.0)
Loading from cache

Writing lock file
Generating autoload files

生成成功。

PS 如果提示：
Warning: This development build of composer is over 30 days old. It is recommended to update it by running "C:\ProgramData\ComposerSetup\bin\composer.phar self-update" to get the latest version.

则需要更新composer：
E:\DannyCode\LogTest>composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
- Installing react/promise (v2.0.0)
Downloading: 100%

- Installing guzzlehttp/streams (3.0.0)
Downloading: 100%

- Installing guzzlehttp/ringphp (1.0.0)
Downloading: 100%

- Installing guzzlehttp/guzzle (5.0.0)
Downloading: 100%

Writing lock file
Generating autoload files

参考网站：

http://www.kankanews.com/ICkengine/archives/28197.shtml

http://blog.lixiphp.com/php-composer-install-and-use/#axzz3BglEg0J6

https://packagist.org/

Composer生成PHP依赖包