# MiniHTTP Example
## Overview
This example demonstrates how to use the MiniHTTP library for HTTP and HTTPS communication on K230. MiniHTTP is a lightweight HTTP client library that supports HTTP/HTTPS, SSL/TLS encryption, and file download.
## Functional Description
### MiniHTTP Capabilities
This example demonstrates the main features of MiniHTTP:
- **HTTP/HTTPS support**
- **SSL/TLS encryption**
- **simple APIs**
- **event-driven operation**
- **flexible configuration** for buffer size, timeout, and keep-alive behavior
### Sample Types
This example contains two sub-samples.
#### `minihttp_basic` - Basic Example
The simplest file-download example:
- one-shot download through a simple API
- automatic handling of HTTP connection and data reception
- automatic memory allocation and release
#### `minihttp_advanced` - Advanced Example
An event-driven HTTP client example:
- event callbacks for HTTP responses
- connection lifecycle management
- SSL certificate validation
- receive-data handling
- network-error and timeout handling
### Main APIs
#### Basic API
```cpp
char* minihttp::Download(const char* url);
```
#### Advanced APIs
```cpp
void minihttp::InitNetwork();
void minihttp::StopNetwork();
bool minihttp::HasSSL();
class HttpSocket {
public:
virtual bool Download(const char* url);
virtual void SetKeepAlive(int n);
virtual void SetBufsizeIn(unsigned int size);
protected:
virtual void _OnOpen();
virtual void _OnClose();
virtual void _OnRequestDone();
virtual void _OnRecv(void* buf, unsigned int size);
};
```
## Source Location
```bash
src/rtsmart/examples/3rd-party/minihttp
```
## Usage
### Build Method
#### Firmware Build
From the `K230 RTOS SDK` root, use `make menuconfig` to enable the MiniHTTP example in the firmware, then build the firmware.
#### Standalone Build
Build the basic sample with CMake:
```bash
cd src/rtsmart/examples/3rd-party/minihttp/minihttp_basic
mkdir build && cd build
cmake ..
make
```
Build the advanced sample in the same way.
### Run Example
#### Basic Example
Copy the executable to the board, enter the target directory, then run:
```bash
./test_minihttp
```
### Expected Result
#### Basic Example
The program downloads the content of the target URL and prints it to the console:
```text
Example target page title
...
```
#### Advanced Example
Copy the executable to the board, then run:
```bash
./minihttp_adv
```
Parameter description:
| Parameter | Description |
| --- | --- |
| `url` | URL to download, supports both HTTP and HTTPS |
Example:
```bash
./minihttp_adv https://www.baidu.com
```
Representative output:
```text
minihttp have ssl support: YES
Connecting to: https://www.baidu.com
[Event] _OnOpen()
SSL status flags (0 is good): 0x0
...
[Event] _OnRequestDone(): /
[Event] _OnClose()
Test finished.
```
### SSL Notes
When using HTTPS:
1. the system time must be correct for certificate validation
1. SSL certificates are validated by default
1. an SSL error code of `0x1` often indicates incorrect system time
```{admonition} Tip
MiniHTTP supports HTTP Keep-Alive. You can use `SetKeepAlive()` to configure the keep-alive count and improve performance. For more MiniHTTP details, refer to the related API documentation.
```
```{admonition} Tip
When using HTTPS, make sure the system time is configured correctly; otherwise, SSL certificate validation may fail. You can use the `date` command to set the system time.
```