"transformClassesWithDexForDebug" error while generating apk in Android Studio
<p>We have been developing an phonegap-cordova project in eclipse. Recently we are tying to integrate firebase push message in our app so we migrate to android studio 1.5.
Project is ok .... no problem with building or compiling. But when we try to generate an singed apk then we are getting the following error.</p>

<p>**Error:Execution failed for task ':transformClassesWithDexForDebug'.</p>

<blockquote>
  <p>com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_31\bin\java.exe'' finished with non-zero exit value 1**</p>
</blockquote>

<p>our build.gradle file is given bellow -</p>

<pre><code>apply plugin: 'android'
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.5.0'        //Add this line
        classpath 'com.google.gms:google-services:3.0.0'
    }
   }
repositories {
    mavenCentral()
}
task wrapper(type: Wrapper) {
    gradleVersion = '2.8'
}
ext {
    apply from: 'CordovaLib/cordova.gradle'
    // The value for android.compileSdkVersion.
    if (!project.hasProperty('cdvCompileSdkVersion')) {
        cdvCompileSdkVersion = null;
    }
    // The value for android.buildToolsVersion.
    if (!project.hasProperty('cdvBuildToolsVersion')) {
        cdvBuildToolsVersion = null;
    }
    // Sets the versionCode to the given value.
    if (!project.hasProperty('cdvVersionCode')) {
        cdvVersionCode = null
    }
    // Sets the minSdkVersion to the given value.
    if (!project.hasProperty('cdvMinSdkVersion')) {
        cdvMinSdkVersion = null
    }
    // Whether to build architecture-specific APKs.
    if (!project.hasProperty('cdvBuildMultipleApks')) {
        cdvBuildMultipleApks = null
    }
    // .properties files to use for release signing.
    if (!project.hasProperty('cdvReleaseSigningPropertiesFile')) {
        cdvReleaseSigningPropertiesFile = null
    }
    // .properties files to use for debug signing.
    if (!project.hasProperty('cdvDebugSigningPropertiesFile')) {
        cdvDebugSigningPropertiesFile = null
    }
    // Set by build.js script.
    if (!project.hasProperty('cdvBuildArch')) {
        cdvBuildArch = null
    }
    // Plugin gradle extensions can append to this to have code run at the end.
    cdvPluginPostBuildExtras = []
}
// PLUGIN GRADLE EXTENSIONS START
// PLUGIN GRADLE EXTENSIONS END
def hasBuildExtras = file('build-extras.gradle').exists()
if (hasBuildExtras) {
    apply from: 'build-extras.gradle'
}
// Set property defaults after extension .gradle files.
if (ext.cdvCompileSdkVersion == null) {
    ext.cdvCompileSdkVersion = privateHelpers.getProjectTarget()
}
if (ext.cdvBuildToolsVersion == null) {
    ext.cdvBuildToolsVersion = privateHelpers.findLatestInstalledBuildTools()
}
if (ext.cdvDebugSigningPropertiesFile == null &amp;&amp; file('debug-signing.properties').exists()) {
    ext.cdvDebugSigningPropertiesFile = 'debug-signing.properties'
}
if (ext.cdvReleaseSigningPropertiesFile == null &amp;&amp; file('release-signing.properties').exists()) {
    ext.cdvReleaseSigningPropertiesFile = 'release-signing.properties'
}
// Cast to appropriate types.
ext.cdvBuildMultipleApks = cdvBuildMultipleApks == null ? false : cdvBuildMultipleApks.toBoolean();
ext.cdvMinSdkVersion = cdvMinSdkVersion == null ? null : Integer.parseInt('' + cdvMinSdkVersion)
ext.cdvVersionCode = cdvVersionCode == null ? null : Integer.parseInt('' + cdvVersionCode)
def computeBuildTargetName(debugBuild) {
    def ret = 'assemble'
    if (cdvBuildMultipleApks &amp;&amp; cdvBuildArch) {
        def arch = cdvBuildArch == 'arm' ? 'armv7' : cdvBuildArch
        ret += '' + arch.toUpperCase().charAt(0) + arch.substring(1);
    }
    return ret + (debugBuild ? 'Debug' : 'Release')
}
// Make cdvBuild a task that depends on the debug/arch-sepecific task.
task cdvBuildDebug
cdvBuildDebug.dependsOn {
    return computeBuildTargetName(true)
}
task cdvBuildRelease
cdvBuildRelease.dependsOn {
    return computeBuildTargetName(false)
}
task cdvPrintProps &lt;&lt; {
    println('cdvCompileSdkVersion=' + cdvCompileSdkVersion)
    println('cdvBuildToolsVersion=' + cdvBuildToolsVersion)
    println('cdvVersionCode=' + cdvVersionCode)
    println('cdvMinSdkVersion=' + cdvMinSdkVersion)
    println('cdvBuildMultipleApks=' + cdvBuildMultipleApks)
    println('cdvReleaseSigningPropertiesFile=' + cdvReleaseSigningPropertiesFile)
    println('cdvDebugSigningPropertiesFile=' + cdvDebugSigningPropertiesFile)
    println('cdvBuildArch=' + cdvBuildArch)
    println('computedVersionCode=' + android.defaultConfig.versionCode)
    android.productFlavors.each { flavor -&gt;
        println('computed' + flavor.name.capitalize() + 'VersionCode=' + flavor.versionCode)
    }
}
android {
    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
            jniLibs.srcDirs = ['libs']
        }
    }
    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 22
        multiDexEnabled true
        versionCode cdvVersionCode ?: Integer.parseInt("" + privateHelpers.extractIntFromManifest("versionCode") + "0")
        applicationId privateHelpers.extractStringFromManifest("package")
        if (cdvMinSdkVersion != null) {
            minSdkVersion cdvMinSdkVersion
        }
    }
    lintOptions {
      abortOnError false;
    }
    compileSdkVersion cdvCompileSdkVersion
    buildToolsVersion cdvBuildToolsVersion
    if (Boolean.valueOf(cdvBuildMultipleApks)) {
        productFlavors {
            armv7 {
                versionCode defaultConfig.versionCode + 2
                ndk {
                    abiFilters "armeabi-v7a", ""
                }
            }
            x86 {
                versionCode defaultConfig.versionCode + 4
                ndk {
                    abiFilters "x86", ""
                }
            }
            all {
                ndk {
                    abiFilters "all", ""
                }
            }
        }
    } else if (!cdvVersionCode) {
      def minSdkVersion = cdvMinSdkVersion ?: privateHelpers.extractIntFromManifest("minSdkVersion")
      // Vary versionCode by the two most common API levels:
      // 14 is ICS, which is the lowest API level for many apps.
      // 20 is Lollipop, which is the lowest API level for the updatable system webview.
      if (minSdkVersion &gt;= 20) {
        defaultConfig.versionCode += 9
      } else if (minSdkVersion &gt;= 14) {
        defaultConfig.versionCode += 8
      }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    if (cdvReleaseSigningPropertiesFile) {
        signingConfigs {
            release {
                // These must be set or Gradle will complain (even if they are overridden).
                keyAlias = ""
                keyPassword = "__unset" // And these must be set to non-empty in order to have the signing step added to the task graph.
                storeFile = null
                storePassword = "__unset"
            }
        }
        buildTypes {
            release {
                signingConfig signingConfigs.release
            }
        }
        addSigningProps(cdvReleaseSigningPropertiesFile, signingConfigs.release)
    }
    if (cdvDebugSigningPropertiesFile) {
        addSigningProps(cdvDebugSigningPropertiesFile, signingConfigs.debug)
    }
}
dependencies {
   // compile fileTree(dir: 'libs', include: '*.jar')
   // compile files('libs/android-support-v4.jar')
    compile files('libs/library-1.0.16.jar')
    // SUB-PROJECT DEPENDENCIES START
    debugCompile project(path: "CordovaLib", configuration: "debug")
    releaseCompile project(path: "CordovaLib", configuration: "release")
    // SUB-PROJECT DEPENDENCIES END
    compile 'com.google.firebase:firebase-core:9.4.0'
    compile 'com.google.firebase:firebase-messaging:9.4.0'
}
def promptForReleaseKeyPassword() {
    if (!cdvReleaseSigningPropertiesFile) {
        return;
    }
    if ('__unset'.equals(android.signingConfigs.release.storePassword)) {
        android.signingConfigs.release.storePassword = privateHelpers.promptForPassword('Enter key store password: ')
    }
    if ('__unset'.equals(android.signingConfigs.release.keyPassword)) {
        android.signingConfigs.release.keyPassword = privateHelpers.promptForPassword('Enter key password: ');
    }
}
gradle.taskGraph.whenReady { taskGraph -&gt;
    taskGraph.getAllTasks().each() { task -&gt;
        if (task.name == 'validateReleaseSigning') {
            promptForReleaseKeyPassword()
        }
    }
}
def addSigningProps(propsFilePath, signingConfig) {
    def propsFile = file(propsFilePath)
    def props = new Properties()
    propsFile.withReader { reader -&gt;
        props.load(reader)
    }
    def storeFile = new File(props.get('key.store') ?: privateHelpers.ensureValueExists(propsFilePath, props, 'storeFile'))
    if (!storeFile.isAbsolute()) {
        storeFile = RelativePath.parse(true, storeFile.toString()).getFile(propsFile.getParentFile())
    }
    if (!storeFile.exists()) {
        throw new FileNotFoundException('Keystore file does not exist: ' + storeFile.getAbsolutePath())
    }
    signingConfig.keyAlias = props.get('key.alias') ?: privateHelpers.ensureValueExists(propsFilePath, props, 'keyAlias')
    signingConfig.keyPassword = props.get('keyPassword', props.get('key.alias.password', signingConfig.keyPassword))
    signingConfig.storeFile = storeFile
    signingConfig.storePassword = props.get('storePassword', props.get('key.store.password', signingConfig.storePassword))
    def storeType = props.get('storeType', props.get('key.store.type', ''))
    if (!storeType) {
        def filename = storeFile.getName().toLowerCase();
        if (filename.endsWith('.p12') || filename.endsWith('.pfx')) {
            storeType = 'pkcs12'
        } else {
            storeType = signingConfig.storeType // "jks"
        }
    }
    signingConfig.storeType = storeType
}
for (def func : cdvPluginPostBuildExtras) {
    func()
}
// This can be defined within build-extras.gradle as:
//     ext.postBuildExtras = { ... code here ... }
if (hasProperty('postBuildExtras')) {
    postBuildExtras()
}
//Add this line
//apply plugin: 'com.google.gms.google-services'
apply plugin: com.google.gms.googleservices.GoogleServicesPlugin
</code></pre>

<p>Kindly someone help us how to resolve this problem so that we can generate a signed apk.</p>