can't compile Android app with realm

Question

When I add the realm.io library to my Android app and try to run the app, I get this error during compilation:

Error:Execution failed for task ':compileDebugJava'. > java.lang.ClassCastException: com.sun.tools.javac.code.Symbol$ClassSymbol cannot be cast to javax.lang.model.element.PackageElement

This is my build.gradle:

buildscript {
repositories {
    mavenCentral()
    maven { url 'http://download.crashlytics.com/maven' }
}
dependencies {
    classpath 'com.android.tools.build:gradle:0.13.2'
    classpath 'com.crashlytics.tools.gradle:crashlytics-gradle:1.+'
    classpath 'com.jakewharton.hugo:hugo-plugin:1.1.0'
}
}

apply plugin: 'android'
apply plugin: 'crashlytics'
apply plugin: 'com.android.application'
apply plugin: 'hugo'

repositories {
mavenCentral()
jcenter()
maven { url 'http://download.crashlytics.com/maven' }
}

android {
compileSdkVersion 19
buildToolsVersion '19.1'

defaultConfig {
    minSdkVersion 14
    targetSdkVersion 19
}

buildTypes {
    release {
        runProguard false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
    }
}

packagingOptions {
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/NOTICE.txt'
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/NOTICE'
}

dexOptions {
        jumboMode = true
}

/*sourceSets {
    main {
        manifest.srcFile 'src/main/AndroidManifest.xml'
        java.srcDirs = ['src/main/java', 'src-gen/main/java']
        resources.srcDirs = ['src']
        aidl.srcDirs = ['src']
        renderscript.srcDirs = ['src']
        res.srcDirs = ['res']
        assets.srcDirs = ['assets']
    }
}*/
}

dependencies
    {
        compile project(':libraries:AndroidBootstrap')
        compile 'com.android.support:appcompat-v7:19.+'
        compile 'com.crashlytics.android:crashlytics:1.+'
        compile files('libs/naga-3_0.jar')
        compile files('libs/branch-1.1.1.jar')
        compile 'com.google.code.gson:gson:2.2.4'
        compile 'com.viewpagerindicator:library:2.4.1@aar'
        compile 'com.google.android.gms:play-services:5.0.89'
        compile 'de.greenrobot:eventbus:2.2.1'
        compile 'com.github.kevinsawicki:http-request:5.6'
        compile 'com.maxmind.geoip2:geoip2:0.9.0'
        compile 'com.squareup.retrofit:retrofit:1.4.1'
        compile 'com.squareup.picasso:picasso:2.3.4'
        compile 'de.hdodenhof:circleimageview:1.2.0'
        compile 'com.helpshift:android-aar:3.6.0'
        compile 'io.realm:realm-android:0.73.1'
        compile project(':facebook')
        repositories { maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' } }
        compile('com.segment.analytics.android:core:2.4.1@aar')
        {
            transitive = true
        }
    }

When I remove the realm dependency and code, the app compiles fine. I'm running Android Studio 0.8.14

Answer 1

The problem turned out to be that my realm models were nested classes, instead of top-level classes. Changing that fixed this problem.

Answer 2

You don't have the proper getters and setters for the fields in your model.