Could not find common.jar (android.arch.core:common:1.0.0). Searched in the following locations:

在我解决Could not find com.android.tools.build:gradle:3.0.1这个问题，也就是刚刚写的博客之后，又出现了个Could not find com.android.tools.build:gradle:3.0.1的问题，其实解决方法也很简单，如下：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()//添加到这里
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()//添加到这里
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

在中文注释处添加google()即可，但请注意：google()必须在最上方。