spring boot 2.3.x升级到2.5.x遇到的问题

1. 由于spring security的漏洞，需要将5.5.x 版本升级至5.5.7及其以上，相应的spring boot 版本和 spring cloud版本也需要同步升级，下面是版本对照信息

spring boot 升级到 2.5.15 版本
spring cloud 升级到 2020.0.6 版本

2. 更换 security 依赖，spring security已经从 spring cloud 中独立出来，所以需要替换原先的依赖

       <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-security</artifactId>
        </dependency>

调整为：

       <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

3. 由于spring cloud 更换了负载均衡配置，弃用了ribbon，改用了 loadbalancer

nacos 中需要剔除 ribbon依赖

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <!--不使用Ribbon 进行客户端负载均衡-->
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

4. 跨域配置项变更，CorsRegistry 方法中的 allowedOrigins，需要改写为 allowedOriginPatterns，写法上也有所改变

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

import java.util.ArrayList;
import java.util.List;

@Configuration
public class CorsConfig extends WebMvcConfigurationSupport {
    private CorsConfiguration corsConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        corsConfiguration.setAllowCredentials(true);
        corsConfiguration.setMaxAge(3600L);
        return corsConfiguration;
    }

    @Override
    public void addCorsMappings(CorsRegistry registry) {

        registry.addMapping("/**")
                .allowedOriginPatterns("*")
                .allowCredentials(true)
                .allowedMethods("GET", "POST", "DELETE", "PUT")
                .maxAge(3600);
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", corsConfig());

        CorsConfiguration config = new CorsConfiguration();
        // 是否允许请求带有验证信息
        config.setAllowCredentials(true);

        // 允许访问的客户端域名
        // (springboot2.4以上的加入这一段可解决 allowedOrigins cannot contain the special value "*"问题)
        List<String> allowedOriginPatterns = new ArrayList<>();
        allowedOriginPatterns.add("*");
        config.setAllowedOriginPatterns(allowedOriginPatterns);

        // 设置访问源地址 config.addAllowedOrigin("*"); 设置访问源请求头
        config.addAllowedHeader("*");
        // 设置访问源请求方法
        config.addAllowedMethod("*");
        // 对接口配置跨域设置
        source.registerCorsConfiguration("/**", config);
        return new CorsFilter(source);
    }

    /**
     * 发现如果继承了WebMvcConfigurationSupport，则在yml中配置的相关内容会失效。 需要重新指定静态资源
     *
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**").addResourceLocations("classpath:/static/");
        registry.addResourceHandler("swagger-ui.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
        super.addResourceHandlers(registry);
    }
}

5. application.yml更换本地开发负载均衡调用方式，原先的ribbon写法弃用，改用 loadbalancer 写法

eureka:
  client:
    enabled: false

admin:
  ribbon:
    listOfServers: http://localhost:8081
    NIWSServerListClassName: com.netflix.loadbalancer.ConfigurationBasedServerList

更换为：

spring:
  cloud:
    #    spring升级后，本地开发feign调用方式
    discovery:
      client:
        simple:
          instances:
            admin:
              - instanceId: admin
                host: localhost
                port: 8081