Androidstudio: completed with non-zero exit value2

I am learning how to use the hidden API these days and I know how to use classes.jar.
I have put this .jar class in the application module as a library.

When I run this application, I get

"Error: Execution completed for task ': app: dexDebug'.> Com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process command 'C: \ Program Files \ Java \ jdk1. 8.0_45 \ bin \ java.exe '' exited with non-zero exit value 2 "

I really hope someone can help me.

build.gradle:

apply plugin: 'com.android.application'
android {
    compileSdkVersion 19
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "com.android.wifidisplay"
    }

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

dependencies {
    compile files('classes-dex2jar.jar')
}