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docker部署ActiveMQ并整合到Spring Boot ActiveMQ是由Apache基金会采用Java语言开发的一个开源的消息中间件，完美的遵循JMS规范。ActiveMQ易于实现高级场景，而且只需要付出低消耗。被誉为消息中间件的“瑞士军刀”。常用来处理高并发请求的流量削峰、事务处理。本文，我们通过docker部署ActiveMQ，然后结合ActiveMQ的queue及topic模式，分别介绍在spring boot中的应用。通过docker安装ActiveMQ搜索可用的ActiveMQdocker search activemq我这里下载评星最高的webcenter/activemq下载docker镜像docker pull webcenter/activemq运行dockerdocker run -d --name activemq -p 61616:61616 -p 8161:8161 webcenter/activemq检查是否运行成功打开http://139.198.172.114:8161/，出现以下页面可以点击Manage ActiveMQ broker，默认用户名、密码都是adminSpring Boot整合ActiveMQActiveMQ在实际企业开发中主要有两种模式：点对点模式（Queue）和发布订阅模式（Topic）Queue模式Queue模式即队列（先进先出），消息提供者生产消息发布到Queue中，然后消费者从Queue中取出，并消费消息。这里需要注意的是，消息被消费者消费之后，Queue不再存储，所以消息只能被消费一次。Queue支持存在多个消息消费者，但是对一个消息而言，只会有一个消费者可以消费。创建Spring Boot项目并添加依赖<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-activemq</artifactId> </dependency> <dependency> <groupId>org.apache.activemq</groupId> <artifactId>activemq-pool</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>定义常量Constants.javapublic class Constants { public final static String QUEUEMESSAGE = "queue"; }添加配置类ActiveMQConfig.java@Configuration public class ActiveMQConfig { @Bean public Queue queue(){ return new ActiveMQQueue(Constants.QUEUEMESSAGE); } }创建消息提供者@RestController public class ProducerController { @Resource private JmsMessagingTemplate jmsMessagingTemplate; @Resource private Queue queue; @RequestMapping("/sendQueueMessage/{msg}") public String sendQueueMessage(@PathVariable("msg") String msg) { this.jmsMessagingTemplate.convertAndSend(queue, msg); return msg; } }配置ActiveMQ修改项目配置文件，配置ActiveMQspring.activemq.broker-url=tcp://139.198.172.114:61616 #接收所有消息 spring.activemq.packages.trust-all=true创建消息消费者Consumer.java@Component @Slf4j public class Consumer { @JmsListener(destination = Constants.QUEUEMESSAGE) public void receiveQueueMessage1(String message) { if (null != message) { log.info("收到queue报文1：" + message); } } @JmsListener(destination = Constants.QUEUEMESSAGE) public void receiveQueueMessage2(String message) { if (null != message) { log.info("收到queue报文2：" + message); } } }测试我们访问http://localhost:8083/sendQueueMessage/123，可以查看控制台输出信息可以看到，虽然我们提供了两个消费者，但是实际上只有一个消费者消费成功。Topic模式消息提供者将消息发布到Topic中，同时有多个消费者（订阅者）消费该消息，与Queue模式不同，发布到Topic消息会被所有的订阅者消费。Topic模式与Queue模式类似，我们这里基于Queue模式的代码进行修改。修改配置类ActiveMQConfig.java增加Topic的Bean，修改后代码如下@Configuration public class ActiveMQConfig { @Bean public Queue queue(){ return new ActiveMQQueue(Constants.QUEUEMESSAGE); } @Bean public Topic topic(){ return new ActiveMQTopic(Constants.TOPICMESSAGE); } }修改消息消费者@RestController public class ProducerController { @Resource private JmsMessagingTemplate jmsMessagingTemplate; @Resource private Queue queue; @Resource private Topic topic; @RequestMapping("/sendQueueMessage/{msg}") public String sendQueueMessage(@PathVariable("msg") String msg) { this.jmsMessagingTemplate.convertAndSend(queue, msg); return msg; } @RequestMapping("/sendTopicMessage/{msg}") public String sendTopicMessage(@PathVariable("msg") String msg) { this.jmsMessagingTemplate.convertAndSend(topic, msg); return msg; } }修改消费者@Component @Slf4j public class Consumer { @JmsListener(destination = Constants.QUEUEMESSAGE) public void receiveQueueMessage1(String message) { if (null != message) { log.info("收到queue报文1：" + message); } } @JmsListener(destination = Constants.QUEUEMESSAGE) public void receiveQueueMessage2(String message) { if (null != message) { log.info("收到queue报文2：" + message); } } @JmsListener(destination = Constants.TOPICMESSAGE) public void receiveTopicMessage1(String message) { if (null != message) { log.info("收到topic报文1：" + message); } } @JmsListener(destination = Constants.TOPICMESSAGE) public void receiveTopicMessage2(String message) { if (null != message) { log.info("收到topic报文2：" + message); } } }修改项目配置文件通过spring.jms.pub-sub-domain=true配置启用Topic。server.port=8083 spring.activemq.broker-url=tcp://139.198.172.114:61616 #接收所有消息 spring.activemq.packages.trust-all=true #配置使用topic spring.jms.pub-sub-domain=true测试访问http://localhost:8083/sendTopicMessage/123,查看控制台。可以看到两个订阅者都输出了消息。ActiveMQ监控我们通过http://139.198.172.114:8161/admin/topics.jsp,也可以查看服务器的信息 -
使用docker部署dubbo/dubbox并实现服务提供者、消费者 实现目标基于centos 7，通过docker打包部署dubbox（2.8.4），并实现简单的服务提供者与消费者。前置条件服务器安装JDK1.8并正确配置环境变量开发环境安装JDK1.8并正确配置环境变量开发环境安装maven并正确配置环境变量（建议使用阿里云仓库）安装zookeeperZooKeeper 是 Apache 软件基金会的一个软件项目，它为大型分布式计算提供开源的分布式配置服务、同步服务和命名注册。下载压缩包下载压缩包curl -O https://www.apache.org/dyn/closer.lua/zookeeper/zookeeper-3.7.0/apache-zookeeper-3.7.0-bin.tar.gz解压压缩包tar -zxvf apache-zookeeper-3.7.0-bin.tar.gz修改zookeeper配置文件进入zookeeper配置文件所在目录cd /home/apache-zookeeper-3.7.0-bin/conf修改配置文件cp zoo_sample.cfg zoo.cfg运行zookeepercd /home/apache-zookeeper-3.7.0-bin/bin ./zkServer.sh start检查zookeeper运行状态cd /home/apache-zookeeper-3.7.0-bin/bin ./zkServer.sh statusdubbox打包Dubbox 是一个分布式服务框架，其前身是阿里巴巴开源项目Dubbo ，被国内电商及互联网项目中使用，后期阿里巴巴停止了该项目的维护，当当网便在Dubbo基础上进行优化，并继续维护，为了与原有的Dubbo区分，故将其命名为Dubbox。Dubbox 致力于提供高性能和透明化的RPC远程服务调用方案，以及SOA服务治理方案。简单的说，dubbox就是个服务框架，如果没有分布式的需求，其实是不需要用的，只有在分布式的时候，才有dubbox这样的分布式服务框架的需求，并且本质上是个服务调用的东东，说白了就是个远程服务调用的分布式框架。dubbox没有提供打包好的jar包或者war包，我们需要自己在github下载源码并编译。下载dubbox源码dubbox代码下载地址：https://github.com/dangdangdotcom/dubbox编译代码进入dubbox代码文件见，执行打包命令mvn install -D maven.test.skip=true打包完成后，在dubbo-admin\target中能看到一个dubbo-admin-2.8.4.war修改dubbox配置文件我们用压缩软件打开dubbo-admin-2.8.4.war，打开WEB-INF\dubbo.properties，修改zookeeper地址及对应用户密码，如下：dubbo.registry.address=zookeeper://IP地址:2181 dubbo.admin.root.password=root dubbo.admin.guest.password=guest注意修改成自己zookeeper对应的ip地址 war包修改完成后备用。安装docker我们通过docker部署dubbox。更新yumyum -y update安装依赖 yum install -y yum-utils device-mapper-persistent-data lvm2安装dockeryum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo yum install docker-ce-18.06.0.ce-3.el7启动docker并配置开机启动systemctl start docker systemctl enable docker配置docker为国内源vi /etc/docker/daemon.json输入以下内容{ "registry-mirrors": ["http://hub-mirror.c.163.com", "https://docker.mirrors.ustc.edu.cn"] }通过docker部署dubbox我们这里自己打包一个docker，并部署dubbox创建文件夹创建一个文件夹/home/makedocker,用于存储Dockerfile以及war包。mkdir /home/makedocker cd /home/makedocker将war包上传到/home/makedocker制作Dockerfilevi Dockerfile并输入以下内容FROM registry.cn-hangzhou.aliyuncs.com/shuodao/tomcat-8.5.27 MAINTAINER Laughing COPY dubbo.war /usr/tomcat/webapps/ EXPOSE 8080/tcp打包dockerdocker build -t tomcat-dubbo .启动dockerdocker run -d -p 8888:8080 --name tomcat-dubbo tomcat-dubbo查看docker运行状态docker ps显示以下内容，代表docker运行成功查看dubbox运行状态打开http://139.198.172.114:8888/dubbo，系统要求输入密码，密码为dubbo.properties中配置的密码，输入完成后，正常打开界面如下实现dubbox服务我们创建一个用户服务，作为服务提供者，判断用户是否登录。一个商品服务，作为服务消费者，调用用户是否登录的接口。实现通用服务接口创建一个maven项目，提供基本的接口定义。pom.xml内容如下<?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> <groupId>cc.lisen</groupId> <artifactId>dubbo-common</artifactId> <version>1.0-SNAPSHOT</version> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> </project>创建接口package cc.lisen.dubbo.common.service; /** * 博客：https://lisen.cc * Description: * * @Author: 李森的博客 * DateTime: 2021-07-19 20:20 */ public interface RpcUserService { boolean checkUserLogin(String userName); }将代码部署到本地maven仓库由于我们没有远程maven仓库，所以我们将jar包install到本地仓库。在代码根目录，执行以下命令，打包到本地仓库。mvn install -D maven.test.skip=true实现服务提供者创建服务提供者。pom.xml如下<?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>2.5.2</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>cc.lisen</groupId> <artifactId>dubbo-provider</artifactId> <version>0.0.1-SNAPSHOT</version> <name>dubbo-provider</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.8.4</version> </dependency> <dependency> <groupId>io.dubbo.springboot</groupId> <artifactId>spring-boot-starter-dubbo</artifactId> <version>1.0.0</version> </dependency> <dependency> <groupId>cc.lisen</groupId> <artifactId>dubbo-common</artifactId> <version>1.0-SNAPSHOT</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <includeSystemScope>true</includeSystemScope> <excludes> <exclude> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </exclude> </excludes> </configuration> </plugin> </plugins> </build> </project>实现接口package cc.lisen.dubboprovider.service; import cc.lisen.dubbo.common.service.RpcUserService; import org.springframework.stereotype.Service; /** * 博客：https://lisen.cc * Description: * * @Author: 李森的博客 * DateTime: 2021-07-19 19:56 */ @Service @com.alibaba.dubbo.config.annotation.Service(interfaceClass = RpcUserService.class) public class RpcUserServiceImpl implements RpcUserService{ @Override public boolean checkUserLogin(String userName){ return "admin".equals(userName); } } 修改配置文件配置dubboserver.port=8081 #dubbo提供者的别名，只是个标识 spring.dubbo.application.name=dubbo-provider #zookeeper地址 spring.dubbo.registry.address=zookeeper://139.198.172.114:2181 #dubbo协议 spring.dubbo.protocol.name=dubbo #dubbo端口号 spring.dubbo.protocol.port=20880 #这是你要发布到dubbo的接口所在包位置 spring.dubbo.scan=cc.lisen.dubboprovider.service测试运行项目，然后我们打开dubbo服务端，查看是否注册成功。实现服务消费者创建服务消费者。pom.xml如下<?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>2.5.2</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>cc.lisen</groupId> <artifactId>dubbo-provider</artifactId> <version>0.0.1-SNAPSHOT</version> <name>dubbo-provider</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.8.4</version> </dependency> <dependency> <groupId>io.dubbo.springboot</groupId> <artifactId>spring-boot-starter-dubbo</artifactId> <version>1.0.0</version> </dependency> <dependency> <groupId>cc.lisen</groupId> <artifactId>dubbo-common</artifactId> <version>1.0-SNAPSHOT</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <includeSystemScope>true</includeSystemScope> <excludes> <exclude> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </exclude> </excludes> </configuration> </plugin> </plugins> </build> </project> 创建商品服务package cc.lisen.dubboprovider.service; /** * 博客：https://lisen.cc * Description: * * @Author: 李森的博客 * DateTime: 2021-07-19 20:36 */ public interface GoodService { boolean checkUserLogin(String userName); }创建商品服务类，调用用户登录判断接口package cc.lisen.dubboprovider.service.impl; import com.alibaba.dubbo.config.annotation.Reference; import cc.lisen.dubbo.common.service.RpcUserService; import cc.lisen.dubboprovider.service.GoodService; import org.springframework.stereotype.Service; /** * 博客：https://lisen.cc * Description: * * @Author: 李森的博客 * DateTime: 2021-07-19 19:56 */ @Service public class GoodServiceImpl implements GoodService { @Reference private RpcUserService rpcUserService; @Override public boolean checkUserLogin(String userName) { return rpcUserService.checkUserLogin(userName); } } 测试消费者服务是否正常注册测试创建商品销售接口package cc.lisen.dubboprovider.controller; import cc.lisen.dubboprovider.service.GoodService; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; /** * 博客：https://lisen.cc * Description: * * @Author: 李森的博客 * DateTime: 2021-07-19 20:40 */ @RestController public class GoodController { @Resource private GoodService goodService; @GetMapping("sell/good") public boolean sellGood(){ return goodService.checkUserLogin("admin"); } }
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使用Hystrix实现微服务的熔断处理 Hystrix是Netflix开源的一个延迟和容错库，用于隔离访问远程系统、服务或者第三方库，防止级联失效，从而提升系统的可用性与容错性。Hystrix基本使用添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix</artifactId> <version>2.2.8.RELEASE</version> </dependency>为启动类增加@EnableHystrix注解，从而为项目启用断路器支持@SpringBootApplication @EnableFeignClients @EnableHystrix public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } }修改方法，增加容错能力 @GetMapping("/user/{id}") @HystrixCommand(fallbackMethod = "findByIdFallback", commandProperties = { @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000"), @HystrixProperty(name = "metrics.rollingStats.timeInMilliseconds", value = "10000") }, threadPoolProperties = { @HystrixProperty(name = "coreSize", value = "1"), @HystrixProperty(name = "maxQueueSize", value = "10") }) public User findById(@PathVariable Long id) { return userFeignClient.findById(id); } public User findByIdFallback(Long id, Throwable throwable) { log.info(throwable.getMessage()); User user = new User(); user.setName("默认用户"); return user; }测试我们断开此时的服务提供者，访问方法，可以看到进入了容错方法，并获取到了异常信息。feign集成hystrix{message type="info" content="关于soring Cloud版本提示"/}一定要注意Spring Cloud版本问题，Spring Cloud 2020 后，开启feign的hystrix支持需要在配置文件配置如下feign: circuitbreaker: enabled: true早期版本的Spring Cloud需要配置如下feign: hystrix: enabled: true为feign添加回退通过fallback添加回退通过fallback添加回退，不能获取回退原因。@FeignClient(name = "microservice-provider-user",fallback = UserFeignClientCallback.class) public interface UserFeignClient { /** * 使用Feign自带的注解 @RequestLine * @param id * @return */ @RequestLine("GET /{id}") User findById(@Param("id") Long id); } @Slf4j @Component class UserFeignClientCallback implements UserFeignClient{ /** * 使用Feign自带的注解 @RequestLine * * @param id * @return */ @Override public User findById(Long id) { User user = new User(); user.setName("默认用户"); return user; } }通过fallbackFactory添加回退fallbackFactory是fallback的升级版本，能够获取到回退原因。@FeignClient(name = "microservice-provider-user",fallbackFactory = UserFeignClientCallbackFactory.class) public interface UserFeignClient { /** * 使用Feign自带的注解 @RequestLine * @param id * @return */ @RequestLine("GET /{id}") User findById(@Param("id") Long id); } @Slf4j @Component class UserFeignClientCallbackFactory implements FallbackFactory<UserFeignClient> { @Override public UserFeignClient create(Throwable cause) { return new UserFeignClient() { @Override public User findById(Long id) { log.info(cause.getMessage()); User user = new User(); user.setName("默认用户"); return user; } }; } }温馨提示 日志最好放到各个fallback方法中，而不要放到create方法中，否则在引用启动时，会打印日志。feign项目中Hystrix的监控首先需要添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix</artifactId> <version>2.2.8.RELEASE</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency>启动类添加@EnableHystrix@SpringBootApplication @EnableFeignClients @EnableHystrix public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } }修改配置文件，暴漏地址management: endpoints: web: exposure: include: hystrix.stream测试打开地址http://localhost:8081/actuator/hystrix.stream使用hystrix-dashboard可视化监控项目我们刚才项目监控时，返回的都是Json数据，通过hystrix-dashboard我们可以实现可视化的监控。添加hystrix-dashboard依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId> <version>2.2.8.RELEASE</version> </dependency>在启动类添加@EnableHystrixDashboard注解@SpringBootApplication @EnableFeignClients @EnableHystrix @EnableHystrixDashboard public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } }修改配置文件配置文件添加hystrix: dashboard: proxy-stream-allow-list: "*"如果不添加，监控会提示Unable to connect to Command Metric Stream.测试打开http://localhost:8081/hystrix,监控地址输入http://localhost:8081/actuator/hystrix.stream,title随便输入即可。点击Monitor Stream，然后访问任意的接口，系统输出界面如下
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Spring Cloud 使用Feign实现声明式Rest调用 Feign是Netflix开发的声明式、模块化的HTTP客户端。Feign可以帮我们更加便捷、优雅的调用HTTP API。在Spring Cloud中，使用Feign非常简单，创建一个接口，并在接口上添加一些注解，代码就完成了。基本使用添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> 增加配置文件配置文件与之前类似，不再赘诉。server: port: 8081 eureka: instance: prefer-ip-address: false client: service-url: defaultZone: http://peer1:8761/eureka,http://peer2:8762/eureka spring: application: name: microservice-consumer-movie修改启动类，增加@EnableFeignClients@SpringBootApplication @EnableFeignClients public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } }增加Feign接口/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-18 12:52 */ @FeignClient(name = "microservice-provider-user") public interface UserFeignClient { @RequestMapping(value = "{id}",method = RequestMethod.GET) User findById(@PathVariable Long id); } 调用@RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; // @Resource // private RestTemplate restTemplate; @Resource private UserFeignClient userFeignClient; // @Resource // private LoadBalancerClient loadBalancerClient; @GetMapping("/user-instance") public List<ServiceInstance> showInfo() { return discoveryClient.getInstances("microservice-provider-user"); } @GetMapping("/user/{id}") public User findById(@PathVariable Long id) { // return restTemplate.getForObject("http://microservice-provider-user/"+id, User.class); return userFeignClient.findById(id); } // @GetMapping("log/microservice-provider-user") // public ServiceInstance userLog() { // return loadBalancerClient.choose("microservice-provider-user"); // } }基于代码Feign自定义配置创建配置类创建Feign的配置类UserFeignConfig，需要注意的是，该类不能添加@Configuration注解，如果添加了@Configuration注解，那么该类不能在主应用程序的@ComponentScan注解扫描包内。/** * 博客：https://lisen.cc * Description:feign配置文件 * * @Author: 香草物语 * DateTime: 2021-07-18 15:39 */ public class UserFeignConfig { /** * 将契约改成Feign原生的契约，这样就可以使用Feign自带的注解了 * @return */ @Bean public Contract feignContract(){ return new Contract.Default(); } }修改Feign接口/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-18 12:52 */ @FeignClient(name = "microservice-provider-user",configuration = UserFeignConfig.class) public interface UserFeignClient { /** * 使用Feign自带的注解 @RequestLine * @param id * @return */ @RequestLine("GET /{id}") User findById(@Param("id") Long id); }测试@RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; // @Resource // private RestTemplate restTemplate; @Resource private UserFeignClient userFeignClient; // @Resource // private LoadBalancerClient loadBalancerClient; @GetMapping("/user-instance") public List<ServiceInstance> showInfo() { return discoveryClient.getInstances("microservice-provider-user"); } @GetMapping("/user/{id}") public User findById(@PathVariable Long id) { // return restTemplate.getForObject("http://microservice-provider-user/"+id, User.class); return userFeignClient.findById(id); } // @GetMapping("log/microservice-provider-user") // public ServiceInstance userLog() { // return loadBalancerClient.choose("microservice-provider-user"); // } }再次访问http://localhost:8081/user/1，查看输出全局配置以上我们是根据服务进行配置的，我们也可以进行全局配置。在启动类中添加@EnableFeignClients注解@SpringBootApplication @EnableFeignClients(defaultConfiguration = UserFeignConfig.class) public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } } 使用属性自定义Feign配置配置指定名称的Feign Client修改配置文件server: port: 8081 eureka: instance: prefer-ip-address: false client: service-url: defaultZone: http://peer1:8761/eureka,http://peer2:8762/eureka spring: application: name: microservice-consumer-movie feign: client: config: microservice-provider-user: contract: feign.Contract.Default修改Feign接口@FeignClient(name = "microservice-provider-user") public interface UserFeignClient { /** * 使用Feign自带的注解 @RequestLine * @param id * @return */ @RequestLine("GET /{id}") User findById(@Param("id") Long id); }配置全局Feign Client修改配置文件，将指定名称的Feign Client改成default即可。server: port: 8081 eureka: instance: prefer-ip-address: false client: service-url: defaultZone: http://peer1:8761/eureka,http://peer2:8762/eureka spring: application: name: microservice-consumer-movie feign: client: config: default: contract: feign.Contract.DefaultFeign对压缩的支持可以通过以下配置对请求或相应进行压缩。feign: compression: request: enabled: true mime-types: text/xml,application/xml,application/json min-request-size: 2048 response: enabled: true配置Feign日志feign: client: config: default: contract: feign.Contract.Default logging-level: full compression: request: enabled: true mime-types: text/xml,application/xml,application/json min-request-size: 2048 response: enabled: true logging: level: cc.lisen.microserviceconsumermovie.service.UserFeignClient: debug
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Spring Cloud 服务消费者通过ribbon调用服务提供者 在Spring Cloud Eureka配置集群中，我们介绍了Eureka集群部署的方式。在[pring Cloud Eureka消费者获取服务者信息](https://lisen.cc/back/spring-cloud-eureka-consumer-access-to-service-provider-information.html)中，我们介绍了Eureka集群部署的方式，)中，我们介绍了Eureka服务消费者获取服务提供者信息的方式。这篇文章，我通过ribbon的方式，介绍服务消费者调用服务提供者的方式。服务提供者代码无需改动，我们只基于microservice-consumer-movie增加调用服务提供者的相关代码。基本调用方式修改启动类主要是提供RestTemplate相关Bean，增加@LoadBalanced注解使其具备负载均衡能力。@SpringBootApplication public class MicroserviceConsumerMovieApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceConsumerMovieApplication.class, args); } @Bean @LoadBalanced //基于rest+ribbon的调用方式需要加此注解 public RestTemplate restTemplate(){ return new RestTemplate(); } }调用@RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; @Resource private RestTemplate restTemplate; @GetMapping("/user-instance") public List<ServiceInstance> showInfo(){ return discoveryClient.getInstances("microservice-provider-user"); } @GetMapping("/user/{id}") public User findById(@PathVariable Long id){ return restTemplate.getForObject("http://microservice-provider-user/"+id, User.class); } }其他配置其他配置比如依赖、配置文件，请参考之前的文章。测试访问http://localhost:8081/user/1,正确返回用户信息负载均衡算法Ribbon是Netflix发布的负载均衡器，他有助于控制HTTP和TCP客户端的行为。Ribbon默认为我们提供了很多负载均衡算法，比如轮询、随机等，我们也可为Ribbon实现自定义的轮询算法。使用默认轮询算法测试启动两个客户端还是使用前面的用户服务，我们启动两个服务提供者。java -jar microservice-simple-provider-user-0.0.1-SNAPSHOT.jar --server.port=9001 java -jar microservice-simple-provider-user-0.0.1-SNAPSHOT.jar --server.port=9002此时查看Eureka Server可以查看注册的服务，如下编写测试代码，查看服务信息/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-17 22:11 */ @RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; @Resource private RestTemplate restTemplate; @Resource private LoadBalancerClient loadBalancerClient; @GetMapping("/user-instance") public List<ServiceInstance> showInfo(){ return discoveryClient.getInstances("microservice-provider-user"); } @GetMapping("/user/{id}") public User findById(@PathVariable Long id){ return restTemplate.getForObject("http://microservice-provider-user/"+id, User.class); } @GetMapping("log/microservice-provider-user") public ServiceInstance userLog(){ return loadBalancerClient.choose("microservice-provider-user"); } }多次访问http://localhost:8081/log/microservice-provider-user,查看输出信息可以看到，服务会依次调用9001、9002端口，也就是通过轮询的方式，依次访问两个服务提供者。Ribbon自定义配置很多场景下，可以根据需要自定义Ribbon的配置，例如修改Ribbon负载均衡器规则等。Spring Cloud允许通过Java代码或属性自定义Ribbon的配置。使用代码自定义Ribbon配置使用Ribbon时一定要注意版本的问题，不然会各种报错。springcloud 2020.0.1 版本之后 删除了eureka中的ribbon，替代ribbon的是spring cloud自带的LoadBalancer，默认使用的是轮询的方式。先说一下我这边使用的组件的版本信息：Spring Boot 2.5.2Spring Cloud 2020.0.3添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency>{message type="success" content="无需添加ribbon依赖，eureka-client中已包含"/}配置文件配置文件与上面配置一致，不再单独说明。server: port: 8081 eureka: instance: prefer-ip-address: false client: service-url: defaultZone: http://peer1:8761/eureka,http://peer2:8762/eureka spring: application: name: microservice-consumer-movie自定义轮询规则PeachLoadBalancer.java/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-18 11:54 */ public class PeachLoadBalancer implements ReactorServiceInstanceLoadBalancer { private static final Log log = LogFactory.getLog(PeachLoadBalancer.class); final AtomicInteger position;//请求的次数 final String serviceId; //服务名称 用于提示报错信息的 private int flag = 0; //自己定义的计数器 //两个参数的构造方法 需要服务名称和实例提供者 这个在方法中传递进来 public PeachLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider, String serviceId) { //如果不传人请求次数就自己初始化 反正每次都+1 this(new Random().nextInt(1000), serviceId,serviceInstanceListSupplierProvider); } public PeachLoadBalancer(int seedPosition, String serviceId, ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider) { this.position = new AtomicInteger(seedPosition); this.serviceId = serviceId; this.serviceInstanceListSupplierProvider = serviceInstanceListSupplierProvider; } ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider; @Override public Mono<Response<ServiceInstance>> choose(Request request) { //从服务提供者中获取到当前request请求中的serviceInstances并且遍历 ServiceInstanceListSupplier supplier = serviceInstanceListSupplierProvider .getIfAvailable(NoopServiceInstanceListSupplier::new); return supplier.get(request).next() .map(serviceInstances -> processInstanceResponse(supplier, serviceInstances)); } private Response<ServiceInstance> processInstanceResponse(ServiceInstanceListSupplier supplier, List<ServiceInstance> serviceInstances) { Response<ServiceInstance> serviceInstanceResponse = getInstanceResponse(serviceInstances); if (supplier instanceof SelectedInstanceCallback && serviceInstanceResponse.hasServer()) { ((SelectedInstanceCallback) supplier).selectedServiceInstance(serviceInstanceResponse.getServer()); } return serviceInstanceResponse; } private Response<ServiceInstance> getInstanceResponse(List<ServiceInstance> instances) { if (instances.isEmpty()) { if (log.isWarnEnabled()) { log.warn("No servers available for service: " + serviceId); } return new EmptyResponse(); } //pos是当前请求的次数 这样可以自定义负载均衡的切换 这个每次+1的操作是复制的 最好是不删 int pos = Math.abs(this.position.incrementAndGet()); if (pos%4==0){ //是4的倍数就切换 flag += 1; } if (flag >= instances.size()){ flag = 0; } //主要的就是这句代码设置负载均衡切换 ServiceInstance instance = instances.get(flag); return new DefaultResponse(instance); } }增加轮询配置/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-18 11:21 */ public class CustomLoadBalancerConfiguration { @Bean ReactorLoadBalancer<ServiceInstance> randomLoadBalancer(Environment environment, LoadBalancerClientFactory loadBalancerClientFactory) { String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME); return new PeachLoadBalancer(loadBalancerClientFactory .getLazyProvider(name, ServiceInstanceListSupplier.class), name); } }配置轮询对应的服务/** * 博客：https://lisen.cc * Description:使用RibbonClient为特定name的Ribbon Client自定义配置 * 使用@RibbonClient的configuration，指定Ribbon的配置类 * * @Author: 香草物语 * DateTime: 2021-07-18 10:16 */ @Configuration @LoadBalancerClient(name = "microservice-provider-user",configuration = CustomLoadBalancerConfiguration.class) public class MyRibbonConfig { @Bean @LoadBalanced //基于rest+ribbon的调用方式需要加此注解 public RestTemplate restTemplate() { return new RestTemplate(); } }测试/** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-17 22:11 */ @RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; @Resource private RestTemplate restTemplate; @Resource private LoadBalancerClient loadBalancerClient; @GetMapping("/user-instance") public List<ServiceInstance> showInfo(){ return discoveryClient.getInstances("microservice-provider-user"); } @GetMapping("/user/{id}") public User findById(@PathVariable Long id){ return restTemplate.getForObject("http://microservice-provider-user/"+id, User.class); } @GetMapping("log/microservice-provider-user") public ServiceInstance userLog(){ return loadBalancerClient.choose("microservice-provider-user"); } }多次访问http://localhost:8081/log/microservice-provider-user，可以查看端口号，判断是否根据配置的轮询规则分别访问9001和9002端口。
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Spring Cloud Eureka消费者获取服务者信息 在Spring Cloud Eureka配置集群中，我们介绍了Eureka集群部署的方式，这篇文章，我们继续编写服务的提供者及服务的消费者。服务提供者我们创建microservice-simple-provider-user工程，作为服务的提供者。添加依赖<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency>添加配置文件spring: application: name: microservice-provider-user eureka: client: service-url: default-zone: http://peer1:8761/eureka,http://peer2:8762/eureka instance: prefer-ip-address: true metadata-map: my-metadata: 自定义元数据创建用户实体User.java@Data public class User { private Long id; private String userName; private String name; private Integer age; private BigDecimal balance; }创建服务提供者@RestController public class UserController { @GetMapping("{id}") public User findById(@PathVariable Long id){ User user = new User(); user.setId(id); user.setName("zhangsan"); user.setName("张三"); user.setAge(31); user.setBalance(new BigDecimal(300)); return user; } }服务消费者我们创建microservice-consumer-movie工程，作为服务的消费者。添加依赖 <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency>添加配置文件spring: application: name: microservice-provider-user eureka: client: service-url: default-zone: http://peer1:8761/eureka,http://peer2:8762/eureka instance: prefer-ip-address: true metadata-map: my-metadata: 自定义元数据我们通过metadata-map可以自定义元数据。测试获取服务提供者信息import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.discovery.DiscoveryClient; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import javax.annotation.Resource; import java.util.List; /** * 博客：https://lisen.cc * Description: * * @Author: 香草物语 * DateTime: 2021-07-17 22:11 */ @RestController public class MovieController { @Resource private DiscoveryClient discoveryClient; @GetMapping("/user-instance") public List<ServiceInstance> showInfo(){ return discoveryClient.getInstances("microservice-provider-user"); } }我们访问http://localhost:8081/user-instance，可以获取到服务提供者的详细信息[{ "scheme": "http", "host": "192.168.3.48", "port": 8080, "metadata": { "management.port": "8080", "my-metadata": "自定义元数据" }, "secure": false, "uri": "http://192.168.3.48:8080", "serviceId": "MICROSERVICE-PROVIDER-USER", "instanceId": "DESKTOP-PPDVS3E:microservice-provider-user", "instanceInfo": { "instanceId": "DESKTOP-PPDVS3E:microservice-provider-user", "app": "MICROSERVICE-PROVIDER-USER", "appGroupName": null, "ipAddr": "192.168.3.48", "sid": "na", "homePageUrl": "http://192.168.3.48:8080/", "statusPageUrl": "http://192.168.3.48:8080/actuator/info", "healthCheckUrl": "http://192.168.3.48:8080/actuator/health", "secureHealthCheckUrl": null, "vipAddress": "microservice-provider-user", "secureVipAddress": "microservice-provider-user", "countryId": 1, "dataCenterInfo": { "@class": "com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo", "name": "MyOwn" }, "hostName": "192.168.3.48", "status": "UP", "overriddenStatus": "UNKNOWN", "leaseInfo": { "renewalIntervalInSecs": 30, "durationInSecs": 90, "registrationTimestamp": 1626531693579, "lastRenewalTimestamp": 1626531693579, "evictionTimestamp": 0, "serviceUpTimestamp": 1626531693579 }, "isCoordinatingDiscoveryServer": false, "metadata": { "management.port": "8080", "my-metadata": "自定义元数据" }, "lastUpdatedTimestamp": 1626531693579, "lastDirtyTimestamp": 1626531693019, "actionType": "ADDED", "asgName": null } }]
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Spring Cloud Eureka配置集群 Eureka Server可以通过运行多个实例并通过相互注册的方式实现高可用性的部署。Eureka Server实例会彼此通过增量同步的方式同步信息，确保节点数据之间的一致性。配置hosts由于我这里部署到同一个电脑上，因此需要配置hosts，以便进行服务之间的区分。win电脑hosts文件位于：C:\Windows\System32\drivers\etc\hostsMac及Linux电脑hosts文件位于：/etc/hosts在hosts文件末尾增加以下内容：C:\Windows\System32\drivers\etc配置服务提供者分别创建两个Spring Boot应用，分别为microservice-discovery-eureka、microservice-discovery-eureka-ha，代表两个服务提供者工程。添加依赖两个工程，同时添加以下依赖。<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId> </dependency>修改启动类两个工程的启动类，分别添加@EnableEurekaServer注解。@SpringBootApplication @EnableEurekaServer public class MicroserviceDiscoveryEurekaApplication { public static void main(String[] args) { SpringApplication.run(MicroserviceDiscoveryEurekaApplication.class, args); } }microservice-discovery-eureka配置文件如下spring: application: name: microservice-discovery-eureka server: port: 8761 eureka: instance: hostname: peer1 appname: microservice-discovery-eureka prefer-ip-address: false client: serviceUrl: defaultZone: http://peer2:8762/eureka # false表示不向注册中心注册自己 register-with-eureka: true # false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务 fetch-registry: truemicroservice-discovery-eureka-ha配置文件如下spring: application: name: microservice-discovery-eureka server: port: 8762 eureka: instance: hostname: peer2 appname: microservice-discovery-eureka client: serviceUrl: defaultZone: http://peer1:8761/eureka # false表示不向注册中心注册自己 register-with-eureka: true # false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务 fetch-registry: true可以看到，两个工程通过相互注册的方式，实现集群。配置文件，需要注意以下内容:hostname需要不同appname必须保持一致defaultZone需要使用我们配置的IP映射，而不是使用IP
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spring boot 通过actuator监控应用程序 Spring Boot Actuator提供了很多的监控端点，可以帮助实现对程序内部运行情况监控，比如监控状况、Bean加载情况、环境变量、日志信息、线程信息等。我们可以使用http://{ip}/{port}/actuator/{endpoint}的形式访问这些端点。这些端点大部分是GET方法，当然也有POST方法，比如shutdown。actuator提供的部分端点如下表所示序号端点描述HTTP方法1conditions(老版本为autoconfig）显示自动配置的信息GET2beans显示应用程序所有的Spring beanGET3configprops显示所有@ConfigurationPropertiesGET4threaddump（老版本为dump）显示线程活动快照GET5env显示所有的环境变量GET6health显示应用程序的健康指标，如需显示详情，需要在配置文件配置management.endpoint.health.show-details=alwaysGET7info显示应用信息。GET8mappings显示所有@RequestMapping的路径列表GET9metrics显示应用的度量标准信息GET10shutdown关闭应用，默认关闭，需要在配置文件配置management.endpoint.shutdown=true开启POST11loggers显示日志信息GET12heapdump下载应用程序堆栈信息GET部分配置文件如下，具体内容看注释management: endpoint: beans: enabled: true health: # 显示详细信息 show-details: always shutdown: enabled: true endpoints: web: exposure: # 配置暴漏的端点 include: '*'
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Spring Boot Yaml文件配置特殊字符 Spring Boot中我们一般使用yaml作为配置文件，yaml都是通过键值对的形式，一般情况下，我们的键值都是字母、数字之类的，但是偶尔的，我们可能使用到特殊字符。比如，有时候我们设置actuator时，可以设置暴漏的网址，我们可能为了方便，就直接设置所有的网址，也就是设置*，但是如果直接设置，启动时会报错。对于这种特殊字符，我们可以通过'将特殊字符包裹起来，如下management: endpoint: beans: enabled: true health: # 显示详细信息 show-details: always endpoints: web: exposure: include: '*'
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el-table隐藏顶部复选框 有时候我们使用el-table的选择框时，如果涉及修改、删除时，可能一次只允许用户选择一条，这样的话，如果使用顶部的全选复选框就不合适了。我们可以提供两种方式，一种是隐藏顶部的复选框，另一种是将顶部复选框改成文字，禁止点击。多选框那一列加label-class-name <el-table v-loading="loading" :data="assetClass.assetClassPropertyList" row-key="propertyId" :row-class-name="rowClassName" @selection-change="handleSelectionChange" ref="table"> <el-table-column type="index" width="50" align="center" label="序号"/> <el-table-column type="selection" width="50" align="center" label-class-name="DisabledSelection"/> <el-table-column prop="propertyName" label="属性名称" show-overflow-tooltip align="center"> <template slot-scope="scope"> <el-input v-model="scope.row.propertyName" size="mini" maxlength="64" :show-word-limit="true"></el-input> </template> </el-table-column> <el-table-column prop="isRequired" label="是否必填" :formatter="isRequiredFormatter" width="100"> <template slot-scope="scope"> <el-switch v-model="scope.row.isRequired" active-value="Y" inactive-value="N" ></el-switch> </template> </el-table-column> </el-table>style加样式隐藏顶部复选框<style scoped> /*表格全选框去除空框*/ .el-table >>> .DisabledSelection .cell .el-checkbox__inner { display: none; position: relative; } </style>将顶部复选框改成汉字<style scoped> /*表格全选框去除空框*/ .el-table >>> .DisabledSelection .cell .el-checkbox__inner { display: none; position: relative; } /*表格全选框改为：选择*/ .el-table >>> .DisabledSelection .cell:before { content: "选择"; position: absolute; left: 7px; } </style>
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安卓ListView的item中含有EditText，动态添加item时EditText值的保存 EditText是ListView的item，ListView的item可以动态添加，从而让用户动态输入一些内容。ListView是依靠Adapter将View和数据联系起来的，实现动态添加item的效果，比较简单，只需数据源再加一个条目，比如list.add（…），然后Adapter调用notifyDataSetChanged方法刷新View即可。到这里，我们的关注点来了，我们最终是需要获取ListView中所有EditText的值，保存到本地或者提交至服务器的，那么如何做到呢？我们知道，ListView的每个item都对应着一个实体类对象，显然，这个实体类有一个属性，用于保存EditText的值，在Adapter的getView（）中，又用于EditText值的显示。所以我们需要实刻保存EditText的值到这个实体类对象的属性里，不然当我们调用notifyDataSetChanged刷新视图后会发现，EditText的值为空或者错乱。正如下图的效果：要时刻保存EditText的值，我们需要给EditText设置一个文字改变时的监听器（addTextChangedListener），当文字发生改变后，我们获取EditText的值并存于itemObject的某个属性中。这里千万要脚下留心，在EditText调用setText之前，一定要把textChangedListener移除掉，否则setText后又会多次调用监听器里面的方法，造成值的清空。解决方法是每次getView时先remove掉监听器，再setText，最后再add监听器。适配器的代码如下：import android.content.Context; import android.text.Editable; import android.text.TextUtils; import android.text.TextWatcher; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.EditText; import java.util.List; /** * Created by zengd on 2016/8/17 0017. */ public class ListViewAdapter extends BaseAdapter { private List<ItemBean> mData; private Context mContext; public ListViewAdapter(Context mContext, List<ItemBean> mData) { this.mContext = mContext; this.mData = mData; } @Override public int getCount() { return mData.size(); } @Override public Object getItem(int position) { return mData.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; if (convertView == null) { convertView = LayoutInflater.from(mContext).inflate(R.layout.item_edittext, null); holder = new ViewHolder(convertView); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } final ItemBean itemObj = mData.get(position); if (holder.editText.getTag() instanceof TextWatcher) { holder.editText.removeTextChangedListener((TextWatcher) holder.editText.getTag()); } holder.editText.setText(itemObj.getText()); TextWatcher watcher = new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { } @Override public void afterTextChanged(Editable s) { if (TextUtils.isEmpty(s)) { itemObj.setText(""); } else { itemObj.setText(s.toString()); } } }; holder.editText.addTextChangedListener(watcher); holder.editText.setTag(watcher); return convertView; } private class ViewHolder { private EditText editText; public ViewHolder(View convertView) { editText = (EditText) convertView.findViewById(R.id.edit_text); } } }由于我的实际项目中item里有三个EditText，在这里我简化成只有一个EditText。再多个EditText也是同理实现的。
