网关
解决的问题：
-
自动路由，反向代理，负载均衡鉴权、监控
使用spring cloud gateway
路由匹配predicate 并到达指定位置
请求过来通过handler mapping来判断是否可以处理，能处理通过handler去处理，处理前经过一系列filter
gateway配置
id代表某一条规则 uri代表目的地 predicate代表路由规则，解析请求头、请求方法、请求时间、请求路径等请求参数才可路由到uri的目的地 filter代表过滤器，可在请求过程中额外添加参数使用：
1、添加依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
2、添加路由配置
spring:
cloud:
gateway:
routes:
- id: query_route # 规则id
uri: https://baidu.com # 目的地址
predicates:
- Query=url, baidu # 断言匹配，满足就跳转到目的地址
- id: qq_test
uri: https://qq.com
predicates:
- Query=url, qq
3、具体路由参考官方文档
踩坑：chrome 默认会把url失败后转为https开头，而一般本地请求都是http 导致请求出错
springcloud的gateway报以下错误
原因：
springcloud的版本和springboot的版本对应不上，可能因为springboot版本过低或者springcloud版本过高，去springcloud官网查看对应springboot版本重新依赖即可解决
报错版本：
springcloud：Greenwich.SR5 springboot：2.1.4
调整后版本：
springcloud：Greenwich.SR5 springboot：2.1.8（如果springboot版本大于等于2.2.0还是会报错）
java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.gateway.config.GatewayAutoConfiguration$NettyConfiguration] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@7b1d7fff] at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:507) ~[spring-core-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:404) ~[spring-core-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:389) ~[spring-core-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:447) ~[spring-core-5.1.6.RELEASE.jar:5.1.6.RELEASE] at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1705) ~[na:na] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:738) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:679) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:647) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1518) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:507) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:477) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:598) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:590) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1226) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE] at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:905) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:891) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:877) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:826) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE] at com.changgou.GatewayWebApplication.main(GatewayWebApplication.java:15) ~[classes/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.1.4.RELEASE.jar:2.1.4.RELEASE] Caused by: java.lang.NoClassDefFoundError: reactor/netty/http/client/HttpResponseDecoderSpec at java.base/java.lang.Class.getDeclaredMethods0(Native Method) ~[na:na] at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3167) ~[na:na] at java.base/java.lang.Class.getDeclaredMethods(Class.java:2310) ~[na:na] at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:489) ~[spring-core-5.1.6.RELEASE.jar:5.1.6.RELEASE] ... 26 common frames omitted Caused by: java.lang.ClassNotFoundException: reactor.netty.http.client.HttpResponseDecoderSpec at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583) ~[na:na] at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na] at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na] ... 30 common frames omitted Process finished with exit code 0
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
