Gradle Javadoc fails with “error: package … does n

问题:

Our Gradle build script fails when building Javadocs for Android Studio project for a library we develop, with errors like:

/MY_LOCAL_PATH/MyClass.java:5: error: package com.google.gson does not exist import com.google.gson.Gson;

Details:

We are building an Android library with Gradle, and want to build the Javadocs for it.

The Android Studio project is configured to require a Maven dependency for GSON, although I'm guessing it would happen with every dependency whose lib file is not provided explicitly.

One of our classes, of course, imports com.google.gson.

Here is our Gradle script:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.1.0'

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

allprojects {
    repositories {
        jcenter()
    }
}

apply plugin: 'com.android.library'

android {
    compileSdkVersion 19
    buildToolsVersion '21.1.2'
    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 19
        versionCode 8000
        versionName "0.8.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    productFlavors {
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.google.code.gson:gson:2.2.4'
}

And the task that's expected to build the docs (based on this question):

task generateJavaDocs(type:Javadoc) {
  source = 'src/main/java/com'

  ext.androidJar = "${android.sdkDirectory}/platforms/${android.compileSdkVersion}/android.jar"
  classpath = files(source) + files(ext.androidJar)

  options.memberLevel = JavadocMemberLevel.PUBLIC
  include '**/*.java'
  exclude '**/BuildConfig.java'
  exclude '**/R.java'
}

When reaching this task, Gradle fails with these errors:

/MY_LOCAL_PATH/MyClass.java:5: error: package com.google.gson does not exist import com.google.gson.Gson;

/MY_LOCAL_PATH/MyClass.java:6: error: package com.google.gson does not exist import com.google.gson.JsonParseException;

/MY_LOCAL_PATH/MyClass.java:7: error: package com.google.gson does not exist import com.google.gson.JsonSyntaxException;

/MY_LOCAL_PATH/MyClass.java:8: error: package com.google.gson.reflect does not exist import com.google.gson.reflect.TypeToken;

Anyone has a thoughts on how to solve this?

Thanks!