接这这一篇redis分布式锁-java实现末尾，实现aop+自定义注解 实现分布式锁
1、为什么需要 声明式的分布式锁
编程式分布式锁每次实现都要单独实现，但业务量大功能复杂时，使用编程式分布式锁无疑是痛苦的，而声明式分布式锁不同，声明式分布式锁属于无侵入式，不会影响业务逻辑的实现。
我的为什么要用：使用简单，提升开发效率
2、怎么实现
使用spring aop + 自定义注解来实现
下面来看下spring boot + 自定义注解 如何实现一个声明式的分布式锁
3、看代码
第一步、引入aop 需要 jar包
<!-- SpringBoot AOP start -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
</dependency>
<!-- SpringBoot AOP end -->
第二步、@EnableAspectJAutoProxy 开启AOP
@EnableAspectJAutoProxy
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
第三步：自定义DistributionLock注解
import java.lang.annotation.*;
/**
* 通常 和com.example.demo.annotation.DistributionLockParam 注解配合使用，降低锁粒度
*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
public @interface DistributionLock {
/**
* 分布式锁key
*/
String key();
/**
* 尝试获得锁的时间（单位：毫秒），默认值：5000毫秒
*
* @return 锁key过期时间
*/
long tryLockTime() default 5000;
/**
* 尝试获得锁后，持有锁的时间（单位：毫秒），默认值：60000毫秒
*
* @return
*/
long holdLockTime() default 60000;
/**
* 分布式锁key 的分隔符（默认 :）
*/
String delimiter() default ":";
}
第四步：自定义DistributionLockParam注解
/**
* 分布式锁参数
* 这个注解，是给DistributionLock用来控制锁粒度的
*/
@Target({ElementType.PARAMETER, ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
public @interface DistributionLockParam {
}
第五步：定义分布式锁AOP配置第五步：定义分布式锁AOP配置
import com.example.demo.annotation.DistributionLock;
import com.example.demo.annotation.DistributionLockParam;
import com.example.demo.entity.Resp;
import com.example.demo.redisLock.LockParam;
import com.example.demo.redisLock.RedisLock;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
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.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
/**
* 对springboot中aop切面编程的测试
*/
//切面类
@Aspect
@Component
@Slf4j
@Order(Ordered.HIGHEST_PRECEDENCE)
public class RedisAopAspect {
public RedisAopAspect(){
log.info("分布锁 aop init");
}
/***
* 定义切入点
*/
@Pointcut("execution(@com.example.demo.annotation.DistributionLock * *(..))")
public void pointCut(){
}
@Around(value = "pointCut()")
public Object aroundMethod(ProceedingJoinPoint pjp) {
MethodSignature signature = (MethodSignature) pjp.getSignature();
Method method = signature.getMethod();
/////////////////////AOP 能取得的信息 start////////////////////////
// log.info("目标方法名为:{}",pjp.getSignature().getName());
// log.info("目标方法所属类的简单类名:{}" , pjp.getSignature().getDeclaringType().getSimpleName());
// log.info("目标方法所属类的类名:{}", pjp.getSignature().getDeclaringTypeName());
// log.info("目标方法声明类型:{}" , Modifier.toString(pjp.getSignature().getModifiers()));
// log.info("目标方法返回值类型:{}" , method.getReturnType());
// //获取传入目标方法的参数
// Object[] args = pjp.getArgs();
// for (int i = 0; i < args.length; i++) {
// log.info("第{}个参数为:{}" ,(i + 1) , args[i]);
// }
// log.info("被代理的对象:{}" , pjp.getTarget());
// log.info("代理对象自己:{}" , pjp.getThis());
/////////////////////AOP 能取得的信息 end////////////////////////
//取得注解对象数据
DistributionLock lock = method.getAnnotation(DistributionLock.class);
//分布式锁实际的key
String lockKey = getRealDistributionLockKey(pjp,lock);
//创建分布式锁对象 start
LockParam lockParam = new LockParam(lockKey,lock.tryLockTime(),lock.holdLockTime());
RedisLock redisLock = new RedisLock(lockParam);
//创建分布式锁对象 end
//获取锁
Boolean holdLock = redisLock.lock();
log.info("lockKey:{} holdLock：{} ",lockKey,holdLock);
if(Boolean.FALSE.equals(holdLock)){
//获取锁失败后，处理返回结果
return handleAcquireLockFailReturn(pjp);
}
try {
return pjp.proceed();
} catch (Throwable e) {
e.printStackTrace();
throw new RuntimeException(e.getMessage());
}finally {
if(redisLock!=null){
Boolean unlock = redisLock.unlock();
log.info("释放锁：unlock {}",unlock);
}
}
}
/**
* 分布式锁获取失败，处理方法
* @param pjp
* @return
*/
public Object handleAcquireLockFailReturn(ProceedingJoinPoint pjp){
MethodSignature signature = (MethodSignature) pjp.getSignature();
Method method = signature.getMethod();
Class returnType = method.getReturnType();
//通常每个公司都有自己的统一的返回对象，Resp.class可以根据自己现有的
if(returnType.equals(Resp.class) ){
log.info("返回值类型 Resp");
return Resp.buildFail("业务处理繁忙，请稍后重试");
}
throw new RuntimeException("获取锁失败");
}
/**
* 加了DistributionLockParam注解参数值，按照顺序返回list
* @param pjp
* @return
*/
public List<Object> getDistributionLockParamList(ProceedingJoinPoint pjp){
ArrayList<Object> distributionLockParamList = null;
MethodSignature signature = ((MethodSignature) pjp.getSignature());
//得到拦截的方法
Method method = signature.getMethod();
//获取方法参数注解，返回二维数组是因为某些参数可能存在多个注解
Annotation[][] parameterAnnotations = method.getParameterAnnotations();
// log.info("parameterAnnotations:{}",parameterAnnotations);
//获取全部参数
Object[] objects = pjp.getArgs();
for(int i = 0; i < parameterAnnotations.length; i++){
for(Annotation a: parameterAnnotations[i]){
if(a.annotationType() == DistributionLockParam.class){
//初始化distributionLockParamList
if(distributionLockParamList==null){
distributionLockParamList = new ArrayList();
}
//获得参数值
Object o = objects[i];
distributionLockParamList.add(o);
}
}
}
return distributionLockParamList;
}
/**
* 加了DistributionLockParam注解参数值，拼接成字符串
* @param pjp
* @param lock
* @return
*/
public String getDistributionLockParamStr(ProceedingJoinPoint pjp,DistributionLock lock){
List<Object> distributionLockParamList = getDistributionLockParamList(pjp);
if(distributionLockParamList!=null && distributionLockParamList.size()>0){
StringBuffer sb = new StringBuffer();
for (int i = 0; i < distributionLockParamList.size(); i++) {
Object param = distributionLockParamList.get(i);
sb.append(lock.delimiter());
sb.append(param);
}
return sb.toString();
}
return "";
}
/**
* 返回分布式锁key完整的key
* @param pjp
* @param lock
* @return
*/
public String getRealDistributionLockKey(ProceedingJoinPoint pjp,DistributionLock lock){
String distributionLockParamStr = getDistributionLockParamStr(pjp,lock);
return lock.key().concat(distributionLockParamStr);
}
}
LockParam和RedisLock类已经在 【redis分布式锁-java实现】文章里面有，这里就不贴出来了
Service 使用例子
import com.example.demo.entity.Resp;
public interface IOrderService {
Resp updateOrder(String orderCode, Integer userId, Integer status);
}
import com.example.demo.annotation.DistributionLock;
import com.example.demo.annotation.DistributionLockParam;
import com.example.demo.entity.Resp;
import com.example.demo.service.IOrderService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
@Slf4j
@Service
public class OrderServiceImpl implements IOrderService {
@Override
@DistributionLock(key = "updateOrderSatus",tryLockTime = 1000)
public Resp updateOrder(@DistributionLockParam String orderCode, Integer userId, Integer status){
try {
log.info("updateOrder 处理业务 start");
Thread.sleep(1000*10);
log.info("updateOrder 处理业务 end");
} catch (InterruptedException e) {
e.printStackTrace();
}
return Resp.buildSuccess("修改订单状态成功");
}
}
collection调用service
import com.example.demo.entity.Resp;
import com.example.demo.service.IOrderService;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiImplicitParams;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@Slf4j
@RestController
@RequestMapping(value = "/v1/test")
public class TestController {
@Autowired
IOrderService orderService;
@ApiOperation(value = "修改订单状态")
@ApiImplicitParams({
@ApiImplicitParam(name = "orderCode", value = "订单编号", paramType = "query"),
@ApiImplicitParam(name = "userId", value = "用户ID", paramType = "query"),
@ApiImplicitParam(name = "status", value = "订单状态 1：未发货 2：已发货 3：完成", paramType = "query"),
})
@RequestMapping(value = "/updateOrderStatus", method = RequestMethod.PUT)
public Resp updateOrderStatus(@RequestParam(value = "orderCode")String orderCode,
@RequestParam(value = "userId")Integer userId,
@RequestParam(value = "status")Integer status){
log.info("updateOrderStatus reqParam:orderCode:{},userId:{},status:{}",orderCode,userId,status);
return orderService.updateOrder(orderCode,userId,status);
}
}
4、浏览器swagger调用
5、下面调用一次这个接口，控制台打印的日志
Connected to the target VM, address: '127.0.0.1:63200', transport: 'socket'
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.5.0)
2021-05-25 23:13:10.967 INFO 57853 --- [ main] com.example.demo.DemoApplication : No active profile set, falling back to default profiles: default
2021-05-25 23:13:11.993 INFO 57853 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-05-25 23:13:12.000 INFO 57853 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-05-25 23:13:12.000 INFO 57853 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.46]
2021-05-25 23:13:12.066 INFO 57853 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-05-25 23:13:12.066 INFO 57853 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1059 ms
2021-05-25 23:13:12.119 INFO 57853 --- [ main] com.example.demo.config.RedisAopAspect : 分布锁 aop init
2021-05-25 23:13:12.694 INFO 57853 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-05-25 23:13:12.695 INFO 57853 --- [ main] d.s.w.p.DocumentationPluginsBootstrapper : Context refreshed
2021-05-25 23:13:12.705 INFO 57853 --- [ main] d.s.w.p.DocumentationPluginsBootstrapper : Found 1 custom documentation plugin(s)
2021-05-25 23:13:12.715 INFO 57853 --- [ main] s.d.s.w.s.ApiListingReferenceScanner : Scanning for api listing references
2021-05-25 23:13:12.880 INFO 57853 --- [ main] com.example.demo.DemoApplication : Started DemoApplication in 2.249 seconds (JVM running for 2.777)
2021-05-25 23:13:12.882 INFO 57853 --- [ main] o.s.b.a.ApplicationAvailabilityBean : Application availability state LivenessState changed to CORRECT
2021-05-25 23:13:12.883 INFO 57853 --- [ main] o.s.b.a.ApplicationAvailabilityBean : Application availability state ReadinessState changed to ACCEPTING_TRAFFIC
2021-05-25 23:19:58.582 INFO 57853 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2021-05-25 23:19:58.582 INFO 57853 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2021-05-25 23:19:58.583 INFO 57853 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 1 ms
2021-05-25 23:20:11.970 INFO 57853 --- [nio-8080-exec-2] c.e.demo.controller.TestController : updateOrderStatus reqParam:orderCode:1,userId:2,status:3
2021-05-25 23:20:11.996 INFO 57853 --- [nio-8080-exec-2] com.example.demo.config.RedisAopAspect : lockKey:updateOrderSatus:1 holdLock：true
2021-05-25 23:20:12.000 INFO 57853 --- [nio-8080-exec-2] c.e.demo.service.impl.OrderServiceImpl : updateOrder 处理业务 start
2021-05-25 23:20:22.005 INFO 57853 --- [nio-8080-exec-2] c.e.demo.service.impl.OrderServiceImpl : updateOrder 处理业务 end
2021-05-25 23:20:22.007 INFO 57853 --- [nio-8080-exec-2] com.example.demo.config.RedisAopAspect : 释放锁：unlock true
spring boot启动类：com.example.demo.DemoApplication
swagger 地址：http://127.0.0.1:8080/swagger-ui.html
其他：
如果声明式的分布式锁想实现可重入机制，可以把new RedisLock(lockParam)，替换成这篇文章的 redis分布式锁-可重入锁 就能实现了
代码我已经上传到gitee上了，大家可以下载玩一下，记得star一下