使用OpenCV4的java.lang.ClassNotFoundException

Question

我使用的是Ubuntu 18.04，Android Studio 3.4.1和OpenCV 4.1.0。 我使用OpenCV 4为Android中的对象检测编写了一些代码。 我生成了CameraActiviy.java以完成所有操作。此类从{p>扩展到AppCompactActivity

    import androidx.appcompat.app.AppCompatActivity;

并实现CvCameraViewListener2。

我试图找出问题所在的时间是一个星期。 我已经尝试过此解决方案MultiDexApplicton，此解决方案multidex android x，并且还使缓存/重新启动和清理构建无效。

这是活动的第一部分：

package org.med.objectsdetector;

import android.content.Context;
import android.content.res.AssetManager;
import android.os.Bundle;
import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.dnn.Dnn;
import org.opencv.dnn.Net;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.imgproc.Imgproc;

public class CameraActivity extends AppCompatActivity implements CvCameraViewListener2 {
private static final String TAG = "CameraActivity";
private static final int PERMISSIONS_REQUEST = 1;
private static final String PERMISSION_CAMERA = Manifest.permission.CAMERA;
private static List<String> classNames;
private Net net;
private CameraBridgeViewBase mOpenCvCameraView;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (!hasPermission())
        requestPermission();
    mOpenCvCameraView = findViewById(R.id.CameraView);
    mOpenCvCameraView.setVisibility(CameraBridgeViewBase.VISIBLE);
    mOpenCvCameraView.setCvCameraViewListener(this);
}

例外指向

    setContentView(R.layout.activity_main);

actity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CameraActivity">

<org.opencv.android.JavaCameraView
    android:id="@+id/CameraView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:visibility="visible" />

</androidx.constraintlayout.widget.ConstraintLayout>

我有以下异常堆栈：

Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$2>: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
    at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2561)
    at void androidx.appcompat.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:63)
    at java.lang.Object java.lang.reflect.Constructor.newInstance0(java.lang.Object[]) (Constructor.java:-2)
    at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:334)
    at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:647)
    at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:790)
    at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:730)
    at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:863)
    at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:824)
    at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:515)
    at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:423)
    at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:374)
    at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:707)
    at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:618)
    at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:540)
    at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:136)
    at void org.med.objectsdetector.CameraActivity.onCreate(android.os.Bundle) (CameraActivity.java:41)
    at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:7183)
    at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1220)
    at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2910)
    at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:3032)
    at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
    at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1696)
    at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:105)
    at void android.os.Looper.loop() (Looper.java:164)
    at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6944)
    at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
    at void com.android.internal.os.Zygote$MethodAndArgsCaller.run() (Zygote.java:327)
    at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:1374)
Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.View$OnUnhandledKeyEventListener" on path: DexPathList[[zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/base.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_dependencies_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_resources_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_0_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_1_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_2_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_3_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_4_apk.apk", zip file "/data/app/org.med.objectsdetector-AJQ55ulE9HajBBVOKEDc1A==/split_lib_slice_5_apk.apk", zip file "/data/app/org.med
    at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:93)
    at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:379)
    at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
    at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2561)
    at void androidx.appcompat.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:63)
    at java.lang.Object java.lang.reflect.Constructor.newInstance0(java.lang.Object[]) (Constructor.java:-2)
    at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:334)
    at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:647)
    at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:790)
    at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:730)
    at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:863)
    at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:824)
    at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:515)
    at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:423)
    at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:374)
    at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:707)
    at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:618)
    at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:540)
    at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:136)
    at void org.med.objectsdetector.CameraActivity.onCreate(android.os.Bundle) (CameraActivity.java:41)
    at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:7183)
    at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1220)
    at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2910)
    at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:3032)
    at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
    at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1696)
    at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:105)
    at void android.os.Looper.loop() (Looper.java:164)
    at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6944)
    at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
    at void com.android.internal.os.Zygote$MethodAndArgsCaller.run() (Zygote.java:327)
    at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:1374)

我无法扩展MultiDexApplication，因为我会丢失所有重写的功能。

编辑0

build.gradle（app）：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.0"
    defaultConfig {
        applicationId "org.med.objectsdetector"
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0-alpha03'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    implementation project(path: ':OpenCV')
    implementation 'com.android.support:multidex:1.0.3'
}

我忘记了“ CameraAtivity.java”中的权限请求部分。上面有更新代码。