自定义限流注解LimitAnno
1、pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.6.RELEASE</version> <relativePath /> <!-- lookup parent from repository --> </parent> <groupId>com.meihaocloud</groupId> <artifactId>SpringbootMongodb</artifactId> <version>0.0.1</version> <name>SpringbootMongodb</name> <properties> <java.version>1.8</java.version> </properties> <dependencies> <!-- springboot 整合 log4j --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-logging</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-log4j</artifactId> <version>1.3.8.RELEASE</version> </dependency> <!--end springboot 整合 log4j --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-lang3</artifactId> <!-- <version>3.6</version> --> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> <!-- 须应用commons-pool2 ， 不然会报错 --> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>2.5.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.47</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
application.properties
server.port=80 #spring.redis.cluster.nodes=192.168.8.115:8001,192.168.8.115:8002,192.168.8.115:8003,192.168.8.115:8004,192.168.8.115:8005,192.168.8.115:8006 #spring.redis.lettuce.pool.max-active=8 #spring.redis.lettuce.pool.max-idle=8 #spring.redis.lettuce.pool.min-idle=0 #spring.redis.lettuce.pool.max-wait=1000ms spring.redis.jedis.pool.max-active=10 spring.redis.jedis.pool.max-idle=5 spring.redis.jedis.pool.min-idle=0 spring.redis.jedis.pool.max-wait=-1ms spring.redis.timeout=6000ms spring.redis.host=192.168.8.161 spring.redis.port=6379
2、相关代码
LimitAnno.java 注解类
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* @description 限流注解
*
* @Inherited：在使用此自定义注解时，如果注解在类上面时，子类会自动继承此注解，否则，子类不会继承此注解。这里一定要记住，使用Inherited声明出来的注解，只有在类上使用时才会有效，对方法，属性等其他无效。
* @Target：表示此注解可以放置的位置。常见的位置有：TYPE=枚举或注解上，FIELD=字段上，METHOD=方法上，PARAMETER=函数形参列表中，CONSTRUCTOR=构造函数上，LOCAL_VARIABLE=局部变量上 等等其他位置。
* @Retention：此注解的生命周期。常见的有：SOURCE=源码时期；CLASS=字节码时期（已编译）；RUNTIME=运行时期，通常是用这个的时候要多。
* @Documentd：生成注解文档。
*/
@Inherited
@Target(ElementType.METHOD)
@Documented
@Retention(RetentionPolicy.RUNTIME)
public @interface LimitAnno {
int limit() default 5 ; // 限流数量
int time() default 1 ; // 限流时间，单位秒
Class<?> fallbackClass() default LimitAnno.class ; // 限流后降级的类，不指定就是该Controller
String fallbackMethod() default "" ; // 限流后降级的方法, 参数和返回值类型必须和原方法一致
}注解切面：LimitAspect.java
import java.lang.reflect.Method;
import java.util.concurrent.TimeUnit;
import javax.annotation.Resource;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.reflect.MethodUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Component;
@Component
@Aspect
public class LimitAspect {
private static Log log = LogFactory.getLog(LimitAspect.class);
@Resource
private RedisTemplate<String, Object> redisTemplate;
@Pointcut("@annotation(com.meihaocloud.mongodb.redislock.LimitAnno)")
public void limitAspect() {
}
@Around("limitAspect()")
public Object limitAspectA(ProceedingJoinPoint pjp) throws Throwable {
// 参数名
Object[] args = pjp.getArgs();
Signature signature = pjp.getSignature();
if (!(signature instanceof MethodSignature)) {
return pjp.proceed(args);
}
MethodSignature methodSignature = (MethodSignature) signature;
Method method = methodSignature.getMethod();
LimitAnno limitAnno = method.getAnnotation(LimitAnno.class);
if (limitAnno == null) {
return pjp.proceed(args);
}
int limitCount = limitAnno.limit();
int limitTime = limitAnno.time();
Object bean = pjp.getTarget();
// 类名
String className = bean.getClass().getName();
// 方法名
String methodName = signature.getName();
// 根据类名、方法名、参数 生成key
String key = "limit_" + className + "_" + methodName;
Object result = null;
ValueOperations<String, Object> opsForValue = redisTemplate.opsForValue();
Integer count = null;
synchronized (log) { // 保证原子操作
count = (Integer) opsForValue.get(key);
log.info("count : " + count );
if (count == null || count == 0 || count < 0) {
opsForValue.set(key, 1, limitTime, TimeUnit.SECONDS);
// 执行方法主体，获取结果值
result = pjp.proceed(args);
} else if (count < limitCount) {
opsForValue.set(key, count + 1, limitTime, TimeUnit.SECONDS);
// 执行方法主体，获取结果值
result = pjp.proceed(args);
} else {
// 大于limitCount , 执行降级方法
Class<?> backClass = limitAnno.fallbackClass();
Object newInstance = backClass.newInstance();
if (!(newInstance instanceof LimitAnno)) { // 没有配置Class,默认就是该类
bean = newInstance;
}
String backMethod = limitAnno.fallbackMethod();
if (StringUtils.isNotBlank(backMethod)) { // 没有配置方法，就直接返回null
result = MethodUtils.invokeMethod(bean, backMethod, args);
}
// log.info(result + " ,拒绝访问： thread: " + Thread.currentThread().getId());
}
}
return result;
}
}3、controller
import java.util.concurrent.TimeUnit;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class RedisController {
private static Log log = LogFactory.getLog(LimitAspect.class);
@RequestMapping("/test")
@LimitAnno(limit = 10, fallbackMethod = "redisTestBack", fallbackClass = LimitCallback.class)
public String redisTest(HttpServletRequest request) {
String id = "1001";
// 业务处理
return "ok";
}
public String redisTestBack(HttpServletRequest request) {
// System.out.println("===================限流");
return "limit-error";
}
}LimitCallback.java
import javax.servlet.http.HttpServletRequest;
public class LimitCallback {
public String redisTestBack(HttpServletRequest request) {
// System.out.println("===================限流");
return "limit-error";
}
}
