# RateLimiter

**Repository Path**: programmerry/flow-control

## Basic Information

- **Project Name**: RateLimiter
- **Description**: spring boot 流量控制
控制用户访问api的次数
- **Primary Language**: Java
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 63
- **Created**: 2018-11-06
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# FlowControl(流量控制)  


FlowControl想要解决的问题是控制api访问次数，防止恶意调用api。支持分布式应用的使用。  
spring boot 支持[flowcontrol-spring-boot-starter](https://gitee.com/shiqiyue/flow-control/tree/master/flowcontrol-spring-boot-starter)

*** 
### 原理
拦截链接并计数，如果超过次数，返回错误信息，没有超过次数则通过。  
使用了分布式锁来控制准确的拦截。   
将访问数据保存到redis来保证分布式下的运用。  
分布式下运用注意要redis访问的是同一个数据库  
*** 
### 如何使用 

* 配置流量控制信息  
实现接口FlowControlConfigurer 
```
public class CustomFlowControlConfigurer implements FlowControlConfigurer {
	
	/***
	 * 配置redis客户端
	 */
	@Override
	public RedissonClient redissonClient() {
		Config config = new Config();
		config.useSingleServer().setAddress("redis://localhost:6379");
		RedissonClient redisson = Redisson.create(config);
		return redisson;
	}
	
	/***
	 * 配置拦截成功后-执行的动作
	 */
	@Override
	public FlowControlInterceptAction flowControlInterceptAction() {
		return new DefaultFlowControlInterceptAction();
	}
	
	/***
	 * 配置拦截数据来源
	 */
	@Override
	public FlowControlDao flowControlDao() {
		return new InMemoryFlowControlDao();
	}
	
	/***
	 * 配置redis key的命名策略
	 */
	@Override
	public RedisKeyNameStrategy redisKeyNameStrategy() {
		return new DefaultRedisKeyNameStrategy();
	}
	
}
```

## Filter(servlet过滤器)
```
@Configuration
public class SpringMvcConfig extends WebMvcConfigurerAdapter {
	
	@Autowired
	private CustomFlowControlConfigurer flowControlConfigurer;
	
	/***
	 * 使用servlet的filter
	 * 
	 * @return
	 */
	@Bean
	public FilterRegistrationBean testFilterRegistration() {
		
		FilterRegistrationBean registration = new FilterRegistrationBean();
		registration.setFilter(new FlowControlFilter(flowControlConfigurer));
		registration.addUrlPatterns("/*");
		registration.setName("flowControlFilter");
		registration.setOrder(1);
		return registration;
	}
	
	
	
}
```
## Interceptor(springmvc拦截器)

```
@Configuration
public class SpringMvcConfig extends WebMvcConfigurerAdapter {
	
	@Autowired
	private CustomFlowControlConfigurer flowControlConfigurer;
	
	/***
	 * 使用springmvc的interceptor
	 */
	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		FlowControlHandlerInterceptor flowControlHandlerInterceptor = new FlowControlHandlerInterceptor(
				flowControlConfigurer);
		registry.addInterceptor(flowControlHandlerInterceptor).addPathPatterns("/**");
		
		super.addInterceptors(registry);
	}
	
}
```

### 样例
[flow-control-sample](https://gitee.com/shiqiyue/flow-control/tree/master/flow-control-sample)

### 采用的技术
* [redis](https://redis.io/)
* [redisson](https://github.com/redisson/redisson) 分布式锁和保存访问信息


### License 
Flow Control is Open Source software released under the  [Apache 2.0 license](http://www.apache.org/licenses/LICENSE-2.0.html)