使用Gradle构建项目时的注意事项

1、仓库配置

默认是到maven中央仓库进行下载依赖，由于maven中央仓库服务器在国外，速度可想而知。所以，国内开发者通常会设置优先从国内仓库（如阿里云）下载。

你可能认为，只要这样：

• with groovy

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

• with kotlin

  repositories {
      //...
      maven { setUrl("http://maven.aliyun.com/nexus/content/groups/public/") }
      //...
  }
  

结果：

* What went wrong:
Could not resolve all dependencies for configuration ':detachedConfiguration13'.
Using insecure protocols with repositories, without explicit opt-in, is unsupported. Switch Maven repository 'maven(http://maven.aliyun.com/nexus/content/groups/public/)' to redirect to a secure protocol (like HTTPS) or allow insecure protocols. See https://docs.gradle.org/7.0.2/dsl/org.gradle.api.artifacts.repositories.UrlArtifactRepository.html#org.gradle.api.artifacts.repositories.UrlArtifactRepository:allowInsecureProtocol for more details. 

what fk ? 没办法，看一下gradle的描述：doc

Specifies whether it is acceptable to communicate with a repository over an insecure HTTP connection.

For security purposes this intentionally requires a user to opt-in to using insecure protocols on case by case basis.

Gradle intentionally does not offer a global system/gradle property that allows a universal disable of this check.

大概意思就是：gradle为了安全考虑，防止他人冒充目标服务器，并在资源中植入恶意代码...所以默认禁用使用非官方的中央仓库（包括阿里云），如果你确认信任该仓库，需要你显示声明信任它。

所以你需要这样配置：

• with groovy

  repositories {
      //...
      maven { 
          allowInsecureProtocol = true
          url "http://maven.aliyun.com/nexus/content/groups/public/" 
      }
      //...
  }
  

• with kotlin

  repositories {
       //...
       maven { 
           isAllowInsecureProtocol = true
           setUrl("http://maven.aliyun.com/nexus/content/groups/public/") 
       }
       //...
  }