Android：java.lang.NoClassDefFoundError

Question

我正在嘗試使用JTransforms庫來計算Android應用程序（使用最新的Android Studio）中的數學函數（DoubleFFT_1D）。我正在使用JTransforms website提供的.jar文件，並將其導入到項目中。我已經嘗試了JTransforms修訂版2.4和3.1。代碼編譯沒有錯誤，但是當我得到實際的方法調用，我得到了以下錯誤消息：

09-07 17:30:11.369 E/JavaBinder: *** Uncaught remote exception! (Exceptions are not yet supported across processes.) 
           java.lang.NoClassDefFoundError: Failed resolution of: Lorg/jtransforms/fft/DoubleFFT_1D; 
            at com.algoint.libzante.AutoCorrelation.compute(AutoCorrelation.java:66) 
            at com.algoint.libzante.EstimateACF.estimateInSamplePeriods(EstimateACF.java:104) 
            at <snip> 
com.algoint.zante.BluetoothLeService.broadcastUpdate(BluetoothLeService.java:348) 
            at com.algoint.zante.BluetoothLeService.access$700(BluetoothLeService.java:50) 
            at com.algoint.zante.BluetoothLeService$1.onCharacteristicChanged(BluetoothLeService.java:243) 
            at android.bluetooth.BluetoothGatt$1.onNotify(BluetoothGatt.java:438) 
            at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:399) 
            at android.os.Binder.execTransact(Binder.java:453) 
            Caused by: java.lang.ClassNotFoundException: Didn't find class "org.jtransforms.fft.DoubleFFT_1D" on path: DexPathList[[dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_9-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_8-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_7-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_6-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_5-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_4-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_3-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_2-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_1-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_0-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-json_simple-1.1_9ec115b071c72fb6edf2028f7a57e4ae60bb5a65-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-dropbox-android-sdk-1.5.4_74a0c4010a6328c8c6443241412fa9c5c398a9ab-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-achartengine-1.1.0_0238cc7eb0f70b6065b267fb6df8a8f6b48a5319-classes.dex"],nativeLibraryDirectories=[/data/app/com.algoint.zante-2/lib/arm64, /vendor/lib64, /system/lib64]] 
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) 
            at com.android.tools.fd.runtime.IncrementalClassLoader$DelegateClassLoader.findClass(IncrementalClassLoader.java:90) 
            at java.lang.ClassLoader.loadClass(ClassLoader.java:511) 
            at java.lang.ClassLoader.loadClass(ClassLoader.java:469) 
            at com.algoint.libzante.AutoCorrelation.compute(AutoCorrelation.java:66)  
            at com.algoint.libzante.EstimateACF.estimateInSamplePeriods(EstimateACF.java:104)  
            at <snip> 
com.algoint.zante.BluetoothLeService.broadcastUpdate(BluetoothLeService.java:348)  
            at com.algoint.zante.BluetoothLeService.access$700(BluetoothLeService.java:50)  
            at com.algoint.zante.BluetoothLeService$1.onCharacteristicChanged(BluetoothLeService.java:243)  
            at android.bluetooth.BluetoothGatt$1.onNotify(BluetoothGatt.java:438)  
            at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:399)  
            at android.os.Binder.execTransact(Binder.java:453)  
            Suppressed: java.lang.ClassNotFoundException: Didn't find class "org.jtransforms.fft.DoubleFFT_1D" on path: DexPathList[[zip file "/data/app/com.algoint.zante-2/base.apk"],nativeLibraryDirectories=[/data/app/com.algoint.zante-2/lib/arm64, /vendor/lib64, /system/lib64]] 
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) 
            at java.lang.ClassLoader.loadClass(ClassLoader.java:511) 
            at java.lang.ClassLoader.loadClass(ClassLoader.java:504) 
              ... 12 more 
             Suppressed: java.lang.ClassNotFoundException: Didn't find class "org.jtransforms.fft.DoubleFFT_1D" on path: DexPathList[[dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_9-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_8-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_7-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_6-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_5-classes.dex", dex file "/data/data/com.algoint.zante/files/instant-run/dex/slice-slice_4-classes.dex", dex file "/data/data/com. 

我已經導入jtransforms作爲源文件如下：

import org.jtransforms.fft.DoubleFFT_1D; 

與正確的gradle這個條目：

apply plugin: 'java' 
dependencies { 
    compile fileTree(dir: 'libs', include: ['*.jar']) 
    compile files('libs/JTransforms-3.1-with-dependencies.jar') 
} 

和相應的Android工作室依賴性關係設置：

的項目編譯沒有一個錯誤，並在下面的線拋出和錯誤：

int n = 2 * nextPow2(x.length); 
// Twice the number of elements are required: real and imaginary parts of the FFT are stored consecutively 
double[] f = new double[2 * n]; 
System.arraycopy(x, 0, f, 0, x.length); 
// FFT 
DoubleFFT_1D fft = new DoubleFFT_1D((long) n); // ERROR ON THIS LINE 
// Use "full" to avoid more machinations with symmetry 
fft.realForwardFull(f); 

n個時引發錯誤的值是1024和x的長度是500。 我發現這個錯誤同時包含：「JTransforms-2.4.jar」和「JTransforms-3.1-with-dependencies.jar」。我認爲原始項目是在Maven編譯的，這是否有所作爲？ 你能推薦任何解決方案嗎？ 謝謝。

Answer 1

最終，我找到了一個解決方案。我忽略了.jar文件，並直接將源代碼編譯到項目中。步驟： - 拉爲Jtransforms， 完整的Git倉庫 - ，將它從一個Maven項目的搖籃項目（「gradle這個初始化」）， - 進口它作爲一個模塊到我的項目，然後 - 編譯它
。 我在刪除所有原始.jar文件（埋在目錄中）時遇到了一些麻煩，但是一旦我完成了該項目編譯並運行良好。