引入了阿里的播放器：flutter_aliplayer:^5.4.9
android打包时出现下面错误

* What went wrong:
A problem occurred configuring project ':flutter_aliplayer'.
> Could not resolve all dependencies for configuration ':flutter_aliplayer:classpath'.
   > Using insecure protocols with repositories, without explicit opt-in, is unsupported. Switch Maven repository 'maven(http://maven.aliyun.com/nexus/content/repositories/releases)' to redirect to a secure protocol (like HTTPS) or allow insecure protocols. See https://docs.gradle.org/7.4/dsl/org.gradle.api.artifacts.repositories.UrlArtifactRepository.html#org.gradle.api.artifacts.repositories.UrlArtifactRepository:allowInsecureProtocol for more details. 
> Failed to notify project evaluation listener.
   > Could not get unknown property 'android' for project ':flutter_aliplayer' of type org.gradle.api.Project.
   > Could not get unknown property 'android' for project ':flutter_aliplayer' of type org.gradle.api.Project.

gradle7.0之后使用http就会报错，处理方法就是添加allowInsecureProtocol = true

maven {
      allowInsecureProtocol = true
      url ...
}

或者 在.gradle目录下 init.gradle 文件中添加allowInsecureProtocol的全局判断

allprojects {
    repositories {
        def REPOSITORY_URL = 'http://127.0.0.1:8081/repository/maven-public/'
        all { ArtifactRepository repo ->
            if (repo instanceof MavenArtifactRepository) {
                def url = repo.url.toString()
                if (url.startsWith('https://repo1.maven.org/maven2') || url.startsWith('https://jcenter.bintray.com/')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $REPOSITORY_URL."
                    remove repo
                }
            }
        }
        maven { ArtifactRepository repo ->
            // 判断属性是否存在，之后再设置
            if(repo.metaClass.hasProperty(repo, 'allowInsecureProtocol')){
                allowInsecureProtocol true
            }
            url REPOSITORY_URL
        }
    }
}

。。。但是发现没有地方使用http://maven.aliyun.com/nexus/content/repositories/releases这个地址
真的是苦逼了好久。。。
最后在阿里云上找到源码下载
找到了gradle-wrapper.properties文件然后看到了gradle6.5版本
这个时候突然就顿悟了。。立即点开build.gradle
果然有一行http

 maven { url "http://maven.aliyun.com/nexus/content/repositories/releases" }

Q.E.D.