SpringBoot从入门到精通教程（二十）- 分布式锁用法（基于Redis实现）

港控/mmm° 2021-10-15 03:18 393阅读 0赞

# 需求背景 #

> Springboot集成分布式锁实现：基于Redis实现。通过使用[Spring Integration][]它提供的全局锁实现，同时，它还提供了其他存储的分布式锁实现：如Gemfire，JDBC，Zookeeper等。

# 代码演示 #

**1. 项目目录结构：**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70][]

**2. pom.xml依赖组件**

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    	<modelVersion>4.0.0</modelVersion>
    
    	<parent>
    		<groupId>com.md</groupId>
    		<artifactId>spring-boot2-parent</artifactId>
    		<version>0.0.1-SNAPSHOT</version>
    		<relativePath>../pom.xml</relativePath>
    	</parent>
    
    	<artifactId>spring-boot2-distributed-lock</artifactId>
    	<packaging>jar</packaging>
    
    	<name>spring-boot2-distributed-lock</name>
    	<description>Spring Boot, MVC, Rest API for App</description>
    
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<java.version>1.8</java.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>net.sf.json-lib</groupId>
    			<artifactId>json-lib-ext-spring</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-integration</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.integration</groupId>
    			<artifactId>spring-integration-redis</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-data-redis</artifactId>
    		</dependency>
    	</dependencies>
    
    	<build>
    		<plugins>
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    		</plugins>
    	</build>
    
    </project>

**3. application.yml配置文件**

server:
       port: 9090
    spring:
       redis:
          host: localhost
          port: 7379
          password: a123456
          timeout: 10000
          max-wait: -1

注：这里我把默认redis的端口6379，改成了7379，同时增加了redis密码验证（教程），建议你也都这么做

**4. RedisLockConfiguration.java配置**

package com.md.demo;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.connection.RedisConnectionFactory;
    import org.springframework.integration.redis.util.RedisLockRegistry;
    
    @Configuration
    public class RedisLockConfiguration {
    	
    	@Bean
    	public RedisLockRegistry redisLockRegistry(RedisConnectionFactory redisConnectionFactory) {
    		return new RedisLockRegistry(redisConnectionFactory, "spring-boot");
    	}
    	
    }

# 案例演示 #

InitRest.java文件

package com.md.demo.rest;
    
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.locks.Lock;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.integration.redis.util.RedisLockRegistry;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    /**
     * @author Minbo
     */
    @RestController
    public class InitRest {
    
    	protected static Logger logger = LoggerFactory.getLogger(InitRest.class);
    
    	@Autowired
    	private RedisLockRegistry redisLockRegistry;
    
    	/**
    	 * http://localhost:9090/hello
    	 * 
    	 * @return
    	 */
    	@GetMapping("/hello")
    	public String hello() {
    		logger.info("hello");
    		return "Hello greetings from spring-boot2-distributed-lock";
    	}
    
    	/**
    	 * http://localhost:9090/test
    	 * 
    	 * @return
    	 */
    	@GetMapping("test")
    	public String test() throws InterruptedException {
    		Lock lock = this.redisLockRegistry.obtain("lock");
    		boolean b1 = lock.tryLock(3, TimeUnit.SECONDS);
    		logger.info("b1 is : {}", b1);
    
    		TimeUnit.SECONDS.sleep(5);
    
    		boolean b2 = lock.tryLock(3, TimeUnit.SECONDS);
    		logger.info("b2 is : {}", b2);
    
    		lock.unlock();
    		lock.unlock();
    		
    		return "success";
    	}
    }

访问接口：[http://localhost:9090/test][http_localhost_9090_test]

2019-08-28 23:02:51,189 [http-nio-9090-exec-3] [com.md.demo.MyHttpInterceptor] [INFO] (MyHttpInterceptor.java:38)- 请求参数, url: http://localhost:9090/test, method: GET, params: null
    2019-08-28 23:02:51,238 [http-nio-9090-exec-3] [com.md.demo.rest.InitRest] [INFO] (InitRest.java:44)- b1 is : true
    2019-08-28 23:02:56,285 [http-nio-9090-exec-3] [com.md.demo.rest.InitRest] [INFO] (InitRest.java:49)- b2 is : true

启动第二个实例，比如9091端口，并迅速访问两个实例的/test接口：[http://localhost:9091/test][http_localhost_9090_test]，会在第二个实例上看到日志：

2019-08-28 23:04:46,878 [http-nio-9091-exec-3] [com.md.demo.MyHttpInterceptor] [INFO] (MyHttpInterceptor.java:38)- 请求参数, url: http://localhost:9091/test, method: GET, params: null
    2019-08-28 23:04:50,016 [http-nio-9091-exec-3] [com.md.demo.rest.InitRest] [INFO] (InitRest.java:44)- b1 is : false
    2019-08-28 23:04:55,066 [http-nio-9091-exec-3] [com.md.demo.rest.InitRest] [INFO] (InitRest.java:49)- b2 is : true
    2019-08-28 23:04:55,113 [http-nio-9091-exec-3] [org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet]] [ERROR] (DirectJDKLog.java:182)- Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: You do not own lock at spring-boot:lock] with root cause
    java.lang.IllegalStateException: You do not own lock at spring-boot:lock
    	at org.springframework.integration.redis.util.RedisLockRegistry$RedisLock.unlock(RedisLockRegistry.java:297)
    	at com.md.demo.rest.InitRest.test(InitRest.java:52)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:498)
    	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
    	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:891)
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
    	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
    	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:96)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800)
    	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806)
    	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
    	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    	at java.lang.Thread.run(Thread.java:748)

说明第二个实例没有拿到锁了，即证明了分布式锁的存在

# 实现原理 #

可见源码：RedisLockRegistry.java文件

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70 1][]

# 完整源码下载 #

我的[Github源码地址：][Github]

[https://github.com/hemin1003/spring-boot-study/tree/master/spring-boot2-study/spring-boot2-parent/spring-boot2-distributed-lock][https_github.com_hemin1003_spring-boot-study_tree_master_spring-boot2-study_spring-boot2-parent_spring-boot2-distributed-lock]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70 2][]

# 参考资料 #

[Spring-integration官方仓库][Spring Integration]

[Springboot集成分布式缓存Redis][Springboot_Redis]

[【总结】SpringBoot2实现分布式锁][SpringBoot2]

# 下一章教程 #

[SpringBoot从入门到精通教程（二十一）- MongoDB集成用法][SpringBoot_- MongoDB]

# 该系列教程 #

[SpringBoot从入门到精通教程][SpringBoot]

至此，全部介绍就结束了

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[我的开源项目集Github][Github 1]

期望和大家***一起学习，一起成长***，共勉，O(∩\_∩)O谢谢

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![20180411181545874][]

[Spring Integration]: https://github.com/spring-projects/spring-integration
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70]: /images/20211015/b59ae7e44f7a44d3945bf5cd437b9c21.png
[http_localhost_9090_test]: http://localhost:9090/test
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70 1]: /images/20211015/b348b10e5411456f884d14a95584f87b.png
[Github]: https://github.com/hemin1003/spring-boot-study/tree/master/spring-boot2-study/spring-boot2-parent
[https_github.com_hemin1003_spring-boot-study_tree_master_spring-boot2-study_spring-boot2-parent_spring-boot2-distributed-lock]: https://github.com/hemin1003/spring-boot-study/tree/master/spring-boot2-study/spring-boot2-parent/spring-boot2-distributed-lock
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9oZW1pbi5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70 2]: /images/20211015/c6041aaf6dfc4b299fcbf78ae1b4d70e.png
[Springboot_Redis]: https://blog.csdn.net/hemin1003/article/details/96483538
[SpringBoot2]: https://blog.csdn.net/hemin1003/article/details/88812200
[SpringBoot_- MongoDB]: https://blog.csdn.net/hemin1003/article/details/99637830
[SpringBoot]: https://hemin.blog.csdn.net/column/info/40170
[Link 1]: http://heminit.com/about/
[Github 1]: https://github.com/hemin1003
[20180411181545874]: /images/20211015/86d7a1f13c774cda9394a22d4a425165.png