gradle报错：unable to find valid certification path to requested target

错误信息:

   > Could not resolve com.android.tools.build:gradle:4.0.1.
     Required by:
         project :
      > Could not resolve com.android.tools.build:gradle:4.0.1.
         > Could not get resource 'https://maven.aliyun.com/repository/public/com/android/tools/build/gradle/4.0.1/gradle-4.0.1.pom'.
            > Could not GET 'https://maven.aliyun.com/repository/public/com/android/tools/build/gradle/4.0.1/gradle-4.0.1.pom'.
               > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
      > Could not resolve com.android.tools.build:gradle:4.0.1.
         > Could not get resource 'https://maven.aliyun.com/repository/google/com/android/tools/build/gradle/4.0.1/gradle-4.0.1.pom'.
            > Could not GET 'https://maven.aliyun.com/repository/google/com/android/tools/build/gradle/4.0.1/gradle-4.0.1.pom'.
               > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

解决办法
尝试了各种办法，后来把我电脑的代理Charls关了，可以了！！！，说到底还是代理引起的
如果关了之后还没有起效，可以尝试把AndroidStudio重启一下，如果还有其他代理软件，也可以尝试关一下试试