应用重新启动，由于 AndroidRuntime 异常而无法运行

Question

Gradle构建成功logcat显示E/AndroidRuntime:致命异常：main

--------Logcat错误---------

07-27 23:04:54.813 21702-21702/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.inoalexander.justjava, PID: 21702
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.inoalexander.justjava/com.example.inoalexander.justjava.mainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.inoalexander.justjava.mainActivity" on path: DexPathList[[zip file "/data/app/com.example.inoalexander.justjava-2/base.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_dependencies_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_0_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_1_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_2_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_3_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_4_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_5_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_6_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_7_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_8_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/com.example.inoalexander.justjava-2/lib/arm64, /system/lib64, /vendor/lib64]]
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2819)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2988)
at android.app.ActivityThread.-wrap14(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1631)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6682)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1534)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1424)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.inoalexander.justjava.mainActivity" on path: DexPathList[[zip file "/data/app/com.example.inoalexander.justjava-2/base.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_dependencies_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_0_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_1_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_2_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_3_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_4_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_5_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_6_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_7_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_8_apk.apk", zip file "/data/app/com.example.inoalexander.justjava-2/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/com.example.inoalexander.justjava-2/lib/arm64, /system/lib64, /vendor/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
at android.app.Instrumentation.newActivity(Instrumentation.java:1086)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2809)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2988) 
at android.app.ActivityThread.-wrap14(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1631) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6682) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1534) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1424) 

--------Java代码从这里开始-------

package com.example.inoalexander.justjava;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
/**
* This app displays an order form to order coffee.
*/
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/**
* This method is called when the order button is clicked.
*/
public void submitOrder(View view) {
display(1);
}
/**
* This method displays the given quantity value on the screen.
*/
private void display(int number) {
TextView quantityTextView = (TextView)            findViewById(R.id.quantity_text_view);
quantityTextView.setText("" + number);
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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"
android:orientation="vertical"
tools:context=".MainActivity">

--------XML代码从这里开始-------

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000000"
android:textSize="16sp"
android:layout_marginBottom="16dp"
android:layout_marginLeft="16dp"
android:text="Quantity" />
<TextView
android:id="@+id/quantity_text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000000"
android:textSize="16sp"
android:layout_marginLeft="16dp"
android:layout_marginBottom="16dp"
android:text="0" />
<Button
android:id="@+id/button_id"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_marginLeft="16dp"
android:text="Order"
android:onClick="submitOrder"/>


</LinearLayout>

我不确定，因为这是我创建的第一个不是卡片的应用程序之一。我不知道为什么它没有在我的手机上运行。我正在使用Galaxy Note 5来运行我的构建。

Gradle构建是成功的，没有给我任何错误，但当我尝试在设备上运行它时，它一直试图重新启动应用程序，直到它最终崩溃应用程序。我在这里看了一些答案，并被指示在android工作室中查看我的Logcat。

老实说，我甚至不知道是从Logcat开始的，也不知道它告诉我什么，我看到了这个错误的很多变化，但并不是我的Logcat中的每个错误都有一个特定的变化。

Answer 1

将multidex设置为应用程序级build.gradle文件，如下

android {
compileSdkVersion 27
useLibrary 'org.apache.http.legacy'
defaultConfig {
applicationId "com.core.######"
minSdkVersion 16
targetSdkVersion 27
versionCode 1
versionName "1.0"
multiDexEnabled true // here change
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
}

还添加了依赖

implementation 'com.android.support:multidex:1.0.3'

最后不要忘记清理和重建项目。

Answer 2

异常表示它正在尝试查找类mainActivity，但在您的代码中有MainActivity。

确保AndroidManifest.xml中的活动类名与您的代码相匹配。