php receives post data, usually $_POST can be used, if not, use file_get_contents("php://input");

The data he requested is in json format. It is very simple to process it with PHP. You only need to use json_decode() to parse it and it will become an array in PHP.
Variables such as username and password can be packaged in json.

1. It is recommended to use the following code

$c = file_get_contents('php://input');  //解析获取的二进制流 获取的数据格式是json
$j = json_decode($c, true); //解析json数据，加第二个参数true 是数组 不然是对象

2. Must be able to add

Use $_POST for regular data, use file_get_contents('php://input') for XML and the like;
Don't use $GLOBALS["HTTP_RAW_POST_DATA"], it is obsolete in 7.0.

is equivalent to raw

This problem is easy to solve. First of all, there are two ways to pass the post request parameters:

1. form form submission

2. Submit in json format

The backend and the Android side just need to discuss a way to receive data. It is not as complicated as the author said

What framework does the author use? If you use laravel or lumen, directly connect Request::getContent(), and then json_decode(). If you want to implement it yourself, you can refer to laravel's implementation method:

public function getContent($asResource = false)
    {
        $currentContentIsResource = is_resource($this->content);
        if (PHP_VERSION_ID < 50600 && false === $this->content) {
            throw new \LogicException('getContent() can only be called once when using the resource return type and PHP below 5.6.');
        }

        if (true === $asResource) {
            if ($currentContentIsResource) {
                rewind($this->content);

                return $this->content;
            }

            // Content passed in parameter (test)
            if (is_string($this->content)) {
                $resource = fopen('php://temp', 'r+');
                fwrite($resource, $this->content);
                rewind($resource);

                return $resource;
            }

            $this->content = false;

            return fopen('php://input', 'rb');
        }

        if ($currentContentIsResource) {
            rewind($this->content);

            return stream_get_contents($this->content);
        }

        if (null === $this->content || false === $this->content) {
            $this->content = file_get_contents('php://input');
        }

        return $this->content;
    }