Android Studio error when in Build .apk -Multiple dex files define

I have an Android app completely made and tested. When I generate build apk I get the following error:

Information:Gradle tasks [:app:assembleDebug]
Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Lcom/loopj/android/http/AsyncHttpResponseHandler;
Error:com.android.dex.DexException: Multiple dex files define Lcom/loopj/android/http/AsyncHttpResponseHandler;
Error:  at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:661)
Error:  at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:616)
Error:  at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:598)
Error:  at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
Error:  at com.android.dx.merge.DexMerger.merge(DexMerger.java:198)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:61)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:36)
Error:  at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
Error:  at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
Error:  at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
Error:  at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
Error:  at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Lcom/loopj/android/http/BaseJsonHttpResponseHandler;
Error:com.android.dex.DexException: Multiple dex files define Lcom/loopj/android/http/BaseJsonHttpResponseHandler;
Error:  at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:661)
Error:  at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:616)
Error:  at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:598)
Error:  at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
Error:  at com.android.dx.merge.DexMerger.merge(DexMerger.java:198)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:61)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:36)
Error:  at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
Error:  at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
Error:  at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
Error:  at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
Error:  at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Error:Execution failed for task ':app:transformDexArchiveWithDexMergerForDebug'.
> com.android.build.api.transform.TransformException: com.android.dex.DexException: Multiple dex files define Lcom/loopj/android/http/BaseJsonHttpResponseHandler;

Can someone help me? I really need to generate the APK.

My build.gradle is as follows:

apply plugin: 'com.android.application'

android {
compileSdkVersion 25
buildToolsVersion '26.0.2'
defaultConfig {
    applicationId "com.NanoStima.AndroidClient"
    minSdkVersion 19
    targetSdkVersion 22
        multiDexEnabled true
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

repositories {
mavenCentral()
}

dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.1.1'
testCompile 'junit:junit:4.12'
compile files('libs/activation.jar')
compile files('libs/additionnal.jar')
compile files('libs/mail.jar')

}

dependencies {
compile 'com.google.android.gms:play-services:9.2.0'
compile 'com.google.android.gms:play-services-location:9.2.0'
compile 'com.facebook.android:facebook-android-sdk:4.26.0'
compile 'com.android.support:multidex:1.0.1'

}

 dependencies {
//   compile 'com.github.scribejava:scribejava-apis:3.2.0'
compile 'com.loopj.android:android-async-http:1.4.4'
compile group: 'org.mindrot', name: 'jbcrypt', version: '0.3m'



}


dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:25.0.1'
compile 'com.android.support:design:25.0.1'
}