1. Nacos（服务注册与配置中心）
Nacos Server 安装：
```bash
# 下载 Nacos
wget https://github.com/alibaba/nacos/releases/download/2.2.0/nacos-server-2.2.0.tar.gz
# 解压并启动
tar -xzf nacos-server-2.2.0.tar.gz
cd nacos/bin
sh startup.sh -m standalone
```
服务注册：
```java
@SpringBootApplication
@EnableDiscoveryClient
public class UserServiceApplication {
public static void main(String[] args) {
SpringApplication.run(UserServiceApplication.class, args);
}
}
```
application.yml：
```yaml
spring:
application:
name: user-service
cloud:
nacos:
discovery:
server-addr: localhost:8848
namespace: dev
group: DEFAULT_GROUP
```
配置管理：
```yaml
spring:
cloud:
nacos:
config:
server-addr: localhost:8848
file-extension: yaml
namespace: dev
group: DEFAULT_GROUP
shared-configs:
- data-id: common-config.yaml
group: DEFAULT_GROUP
refresh: true
```
动态配置刷新：
```java
@RestController
@RefreshScope
public class ConfigController {
@Value("${app.name:default}")
private String appName;
@GetMapping("/config")
public String getConfig() {
return appName;
}
}
```
2. Sentinel（流量控制）
依赖：
```xml
com.alibaba.cloud
spring-cloud-starter-alibaba-sentinel
```
配置：
```yaml
spring:
cloud:
sentinel:
transport:
dashboard: localhost:8080
port: 8719
datasource:
flow:
nacos:
server-addr: localhost:8848
dataId: ${spring.application.name}-flow-rules
groupId: SENTINEL_GROUP
rule-type: flow
```
流量控制：
```java
@Service
public class UserService {
@SentinelResource(value = "getUser", blockHandler = "getUserBlockHandler")
public User getUser(Long id) {
return userRepository.findById(id)
.orElseThrow(() -> new UserNotFoundException(id));
}
public User getUserBlockHandler(Long id, BlockException ex) {
return new User(); // 降级处理
}
}
```
熔断降级：
```java
@SentinelResource(
value = "getUser",
fallback = "getUserFallback",
blockHandler = "getUserBlockHandler"
)
public User getUser(Long id) {
// 业务逻辑
}
public User getUserFallback(Long id, Throwable ex) {
// 降级处理
return new User();
}
```
3. RocketMQ（消息队列）
依赖：
```xml
com.alibaba.cloud
spring-cloud-starter-alibaba-rocketmq
```
配置：
```yaml
spring:
cloud:
stream:
rocketmq:
binder:
name-server: localhost:9876
bindings:
output:
producer:
group: user-service-group
```
消息发送：
```java
@Service
public class UserService {
private final RocketMQTemplate rocketMQTemplate;
public UserService(RocketMQTemplate rocketMQTemplate) {
this.rocketMQTemplate = rocketMQTemplate;
}
public void sendUserCreatedEvent(User user) {
rocketMQTemplate.convertAndSend("user-topic", user);
}
}
```
消息接收：
```java
@Component
@RocketMQMessageListener(
topic = "user-topic",
consumerGroup = "user-consumer-group"
)
public class UserEventListener implements RocketMQListener {
@Override
public void onMessage(User user) {
// 处理消息
System.out.println("Received user: " + user.getName());
}
}
```
4. Seata（分布式事务）
依赖：
```xml
com.alibaba.cloud
spring-cloud-starter-alibaba-seata
```
配置：
```yaml
spring:
cloud:
alibaba:
seata:
tx-service-group: my-tx-group
enabled: true
seata:
enabled: true
application-id: ${spring.application.name}
tx-service-group: my-tx-group
config:
type: nacos
nacos:
server-addr: localhost:8848
namespace: ""
group: SEATA_GROUP
registry:
type: nacos
nacos:
server-addr: localhost:8848
namespace: ""
group: SEATA_GROUP
```
使用 @GlobalTransactional：
```java
@Service
public class OrderService {
@GlobalTransactional
public void createOrder(Order order) {
// 1. 创建订单
orderRepository.save(order);
// 2. 扣减库存
productService.reduceStock(order.getProductId(), order.getQuantity());
// 3. 扣减余额
accountService.deductBalance(order.getUserId(), order.getAmount());
}
}
```
5. Dubbo（RPC 框架）
依赖：
```xml
com.alibaba.cloud
spring-cloud-starter-dubbo
```
配置：
```yaml
spring:
cloud:
dubbo:
application:
name: user-service
registry:
address: nacos://localhost:8848
protocol:
name: dubbo
port: 20880
```
服务提供者：
```java
@Service
@org.apache.dubbo.config.annotation.Service
public class UserServiceImpl implements UserService {
public User getUser(Long id) {
return userRepository.findById(id).orElseThrow();
}
}
```
服务消费者：
```java
@Service
public class OrderService {
@org.apache.dubbo.config.annotation.Reference
private UserService userService;
public Order createOrder(Long userId, Order order) {
User user = userService.getUser(userId);
// 创建订单逻辑
return order;
}
}
```
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