升级Gradle版本的Android APP时出现Filoreader升级问题

Question

我正在尝试将我的android应用程序升级为最新的Gradle版本，并想迁移android x，但是我面临的问题是，它始终向我显示此错误消息“未指定compileSdkVersion。请添加到build.gradle中模块：folioreader“。甚至我也尝试在filoreader的Gradle文件中手动添加Assign compileSdkVersion。

apply plugin: 'com.android.library'
apply from: '../config/quality/quality.gradle'
`enter code here`//apply plugin: 'com.github.dcendents.android-maven'
    
ext {
    bintrayRepo = 'maven'
    bintrayName = 'folioreader'
    
    publishedGroupId = 'com.folioreader'
    libraryName = 'FolioReader'
    artifact = 'folioreader'
    
    libraryDescription = 'An epub reader for Android'
    
    siteUrl = 'https://github.com/MobilionOSS/FolioReader-Android-M'
    gitUrl = 'https://github.com/MobilionOSS/FolioReader-Android-M.git'
    
    libraryVersion = '0.3.8.2'
    
    developerId = 'mobisystech'
    developerName = 'Folio Reader'
    developerEmail = 'mahavir@codetoart.com'
    
    licenseName = 'FreeBSD License'
    licenseUrl = 'https://en.wikipedia.org/wiki/FreeBSD_Documentation_License#License'
        allLicenses = ["FreeBSD"]
}
    
android {
    
    useLibrary 'org.apache.http.legacy'
    
    compileSdkVersion Integer.parseInt(project.ANDROID_TARGET_SDK_VERSION)
       // buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION
    
    defaultConfig {
        versionCode Integer.parseInt(project.VERSION_CODE)
        versionName project.VERSION_NAME
        minSdkVersion Integer.parseInt(project.ANDROID_MIN_SDK)
        targetSdkVersion Integer.parseInt(project.ANDROID_TARGET_SDK_VERSION)
    }
    
    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src/main/java']
            res.srcDirs = ['res']
        }
        test {
            java.srcDirs = ['src/test/java']
        }
    }
    
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    packagingOptions {
        exclude 'META-INF/ASL2.0'
        exclude 'META-INF/DEPENDENCIES.txt'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/dependencies.txt'
        exclude 'META-INF/LGPL2.1'
        exclude 'META-INF/services/javax.annotation.processing.Processor'
    }
    
    lintOptions {
        abortOnError false
    }

    checkstyle {
        ignoreFailures = true
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation project(':webViewMarker')

    final ANDROID_LIB_VERSION = '28.0.0'

    //noinspection GradleDependency
    implementation "com.android.support:appcompat-v7:$ANDROID_LIB_VERSION"
    implementation "com.android.support:recyclerview-v7:$ANDROID_LIB_VERSION"
    implementation "com.android.support:support-v4:$ANDROID_LIB_VERSION"
    implementation "com.android.support:design:$ANDROID_LIB_VERSION"

    implementation 'com.daimajia.swipelayout:library:1.2.0@aar'
    // r2-streamer
    final R2_STREAMER_VERSION = '0.1.4'

    implementation "org.readium:r2-fetcher:$R2_STREAMER_VERSION"
    implementation "org.readium:r2-parser:$R2_STREAMER_VERSION"
    implementation "org.readium:r2-server:$R2_STREAMER_VERSION"

    implementation 'org.greenrobot:eventbus:3.1.1'
}

/*apply from: '../folioreader/bintray/installv1.gradle'
apply from: '../folioreader/bintray/bintrayv1.gradle'*/