一个注解搞定 Spring Boot 接口防刷
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共 7715字，需浏览 16分钟
·
2021-07-26 23:51
一，技术要点：Spring Boot的基本知识，Redis基本操作，
首先是写一个注解类：
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
@Retention(RUNTIME)
@Target(METHOD)
public @interface AccessLimit {
int seconds();
int maxCount();
boolean needLogin()default true;
}
接着就是在Interceptor拦截器中实现：
import com.alibaba.fastjson.JSON;
import com.example.demo.action.AccessLimit;
import com.example.demo.redis.RedisService;
import com.example.demo.result.CodeMsg;
import com.example.demo.result.Result;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
@Component
public class FangshuaInterceptor extends HandlerInterceptorAdapter {
@Autowired
private RedisService redisService;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//判断请求是否属于方法的请求
if(handler instanceof HandlerMethod){
HandlerMethod hm = (HandlerMethod) handler;
//获取方法中的注解,看是否有该注解
AccessLimit accessLimit = hm.getMethodAnnotation(AccessLimit.class);
if(accessLimit == null){
return true;
}
int seconds = accessLimit.seconds();
int maxCount = accessLimit.maxCount();
boolean login = accessLimit.needLogin();
String key = request.getRequestURI();
//如果需要登录
if(login){
//获取登录的session进行判断
//.....
key+=""+"1"; //这里假设用户是1,项目中是动态获取的userId
}
//从redis中获取用户访问的次数
AccessKey ak = AccessKey.withExpire(seconds);
Integer count = redisService.get(ak,key,Integer.class);
if(count == null){
//第一次访问
redisService.set(ak,key,1);
}else if(count < maxCount){
//加1
redisService.incr(ak,key);
}else{
//超出访问次数
render(response,CodeMsg.ACCESS_LIMIT_REACHED); //这里的CodeMsg是一个返回参数
return false;
}
}
return true;
}
private void render(HttpServletResponse response, CodeMsg cm)throws Exception {
response.setContentType("application/json;charset=UTF-8");
OutputStream out = response.getOutputStream();
String str = JSON.toJSONString(Result.error(cm));
out.write(str.getBytes("UTF-8"));
out.flush();
out.close();
}
}
再把Interceptor注册到springboot中
import com.example.demo.ExceptionHander.FangshuaInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
@Autowired
private FangshuaInterceptor interceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(interceptor);
}
}
接着在Controller中加入注解
import com.example.demo.result.Result;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class FangshuaController {
@AccessLimit(seconds=5, maxCount=5, needLogin=true)
@RequestMapping("/fangshua")
@ResponseBody
public Result<String> fangshua(){
return Result.success("请求成功");
}
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