简介：
- 负载均衡框架，支持可插拔式的负载均衡规则
- 支持多种协议，如Http,UDP等
- 提供负载均衡的客户端(用在服务调用者client)
Ribbon子模块
ribbon-core
ribbon-eureka
ribbon-httpclient
负载均衡器组件
1、一个负载均衡器，至少提供以下功能
2、为了实现基本的负载均衡功能，Ribbon的负载均衡器有三大子模块
模拟@LoadBalanced原理
1、新建一个注解
package spring.cloud.spring_member.controller.locdbalaned; import org.springframework.beans.factory.annotation.Qualifier; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * 自定义负载均衡的注解 * * @param * @return * @date 2019-06-16 13:57 */ @Target({ElementType.FIELD,ElementType.PARAMETER,ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Qualifier public @interface MyLoadBalanced { } 2、注册RestTemplate实例到容器中，并加上自定义的注解
package spring.cloud.spring_member.controller.locdbalaned; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.MediaType; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; import java.awt.*; /** * 类的描述 TODO * * @author wangwei * @Date 2019-06-16 14:04 */ @RestController @Configuration public class MyController { @Bean @MyLoadBalanced RestTemplate tplA() { return new RestTemplate(); } @Bean @MyLoadBalanced RestTemplate tplB() { return new RestTemplate(); } @RequestMapping(value = "/call", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE) public String call() { RestTemplate tpl = tplA(); //被拦截器拦截，拦截器内部实现负载均衡 String json = tpl.getForObject("http://app-member-server/call", String.class); return json; } } 3、自定义拦截器，可以可以写负载均衡逻辑，todo
package spring.cloud.spring_member.controller.locdbalaned; import org.springframework.http.HttpRequest; import org.springframework.http.client.ClientHttpRequestExecution; import org.springframework.http.client.ClientHttpRequestInterceptor; import org.springframework.http.client.ClientHttpResponse; import java.io.IOException; /** * 自定义拦截器 * * @author wangwei * @Date 2019-06-16 14:08 */ public class MyInterceptor implements ClientHttpRequestInterceptor { @Override public ClientHttpResponse intercept(HttpRequest httpRequest, byte[] bytes, ClientHttpRequestExecution clientHttpRequestExecution) throws IOException { System.out.println("=========自定义拦截器"); System.out.println("=========" + httpRequest.getURI()); //可以在这里写负载均衡逻辑代码 return null; } } 4、定义配置类，给tpls自动装配restTemplate，并且给restTemplate的拦截器增加自定义的拦截器
package spring.cloud.spring_member.controller.locdbalaned; import org.springframework.beans.factory.SmartInitializingSingleton; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.client.ClientHttpRequestInterceptor; import org.springframework.web.client.RestTemplate; import java.util.Collections; import java.util.List; import java.util.stream.Collectors; /** * 定义配置类，给restTemplate的拦截器增加自定义的拦截器 * @Date 2019-06-16 14:01 */ @Configuration public class MyConfig { @Autowired(required = false) @MyLoadBalanced private List<RestTemplate> tpls = Collections.emptyList(); @Bean public SmartInitializingSingleton Ibinitalizing() { return new SmartInitializingSingleton() { @Override public void afterSingletonsInstantiated() { System.out.println(tpls.size()); for(RestTemplate restTemplate : tpls){ List<ClientHttpRequestInterceptor> interceptors = restTemplate.getInterceptors(); interceptors.add(new MyInterceptor()); restTemplate.setInterceptors(interceptors); } } }; } } 4、
文章来源: https://blog.csdn.net/m0_37668842/article/details/92381088