Gradle 构建错误：无法从 https://repo1.maven.org/maven2/io/fabric/tools/gradle/maven-metadata.xml 加载 Maven 元数据

我在Android工作室中收到一个gradle构建错误，如下所示：

    Error:A problem occurred configuring project ':MyApp'.
    Could not resolve all dependencies for configuration ':MyApp:classpath'.
    Could not resolve io.fabric.tools:gradle:1.+.     
Required by:
    sw-android:MyApp:unspecified
    Failed to list versions for io.fabric.tools:gradle.
        Unable to load Maven meta-data from     
    https://repo1.maven.org/maven2/io/fabric/tools/gradle/maven-metadata.xml.
     Could not GET 'https://repo1.maven.org/maven2/io/fabric/tools/gradle/maven-metadata.xml'.
    peer not authenticated
        Failed to list versions for io.fabric.tools:gradle.
        Unable to load Maven meta-data from  
        http://maven.fabric.io/public/io/fabric/tools/gradle/maven-metadata.xml.
        Could not GET http://maven.fabric.io/public/io/fabric/tools/gradle/maven-metadata.xml'.
        peer not authenticated

我发现“https”标签无法下载Maven URL，因此我在build.gradle文件中将https更改为http。此外，我检查了所有的gradle设置并手动修改了路径C：\Users\Ashfaque1.AndroidStudio\config\options\中的另一.xml文件，但它仍然采取了 https://repo1.maven.org/maven2/io/fabric/tools/gradle/maven-metadata.xml。此外，一旦我点击浏览器的此链接，我就会得到404异常，但错误 http://maven.fabric.io/public/io/fabric/tools/gradle/maven-metadata.xml 中的第二个URL，我能够成功点击并在我的系统中正确下载元数据文件。无法理解问题所在，我需要更改设置才能下载元数据文件。请建议我是否需要更改任何设置或从中获取此URL的位置 https://repo1.maven.org/maven2//io/fabric/tools/gradle/maven-metadata.xml

我的 build.gradle 文件如下：

    apply plugin: 'com.android.application'
    apply plugin: 'io.fabric'

    buildscript {
    repositories {
        mavenCentral()
        maven { url 'http://maven.fabric.io/public' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.1.0'
        classpath 'io.fabric.tools:gradle:1.+'
    }
    }

    repositories {
        mavenCentral()
        maven { url 'http://maven.fabric.io/public' }
    }

    dependencies {
    compile 'com.android.support:multidex:1.0.0'
    compile fileTree(dir: 'libs',include: '*.jar')
    compile project(':DeviceService')
    compile project(':RatioCommon')
    compile project(':SlidingMenu:library')   
    compile project(':SmartViewLibrary:SmartView')
    compile project(':SmartViewLibrary:OpenAccess')
    compile('com.crashlytics.sdk.android:crashlytics:2.2.0@aar') {
        transitive = true;
    }
   }
   compileSdkVersion 21
   buildToolsVersion "21.1.2"

   defaultConfig {
        minSdkVersion 18
        targetSdkVersion 21


        // Enabling multidex support.
        multiDexEnabled true
    }

    dexOptions {
        javaMaxHeapSize "4g"
    }
   }