android studio在4.4或4.2手机系统出现java.lang.ClassNotFoundException的解决办法

android studio 设置 argeted SDK version 24 and minimum version 17 程序可以正常运行，在系统为7.0的手机上可以运行，但是运行在4.2的手机上出现如下错误

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{se.android/se.android.SplashScreenActivity}: java.lang.ClassNotFoundException: Didn't find class "se.android.SplashScreenActivity" on path: DexPathList[[zip file "/data/app/se.android-2.apk"],nativeLibraryDirectories=[/data/app-lib/se.android-2, /vendor/lib, /system/lib]]                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121)                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)                  at android.app.ActivityThread.access$800(ActivityThread.java:135)                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)                  at android.os.Handler.dispatchMessage(Handler.java:102)                  at android.os.Looper.loop(Looper.java:136)                  at android.app.ActivityThread.main(ActivityThread.java:5017)                  at java.lang.reflect.Method.invokeNative(Native Method)                  at java.lang.reflect.Method.invoke(Method.java:515)                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)                  at dalvik.system.NativeStart.main(Native Method)               Caused by: java.lang.ClassNotFoundException: Didn't find class "se.android.SplashScreenActivity" on path: DexPathList[[zip file "/data/app/se.android-2.apk"],nativeLibraryDirectories=[/data/app-lib/se.android-2, /vendor/lib, /system/lib]]                  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)                  at java.lang.ClassLoader.loadClass(ClassLoader.java:497)                  at java.lang.ClassLoader.loadClass(ClassLoader.java:457)                  at android.app.Instrumentation.newActivity(Instrumentation.java:1061)                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112)                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)                   at android.app.ActivityThread.access$800(ActivityThread.java:135)                   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)                   at android.os.Handler.dispatchMessage(Handler.java:102)                   at android.os.Looper.loop(Looper.java:136)                   at android.app.ActivityThread.main(ActivityThread.java:5017)                   at java.lang.reflect.Method.invokeNative(Native Method)                   at java.lang.reflect.Method.invoke(Method.java:515)                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)                   at dalvik.system.NativeStart.main(Native Method) 

解决办法：

defaultConfig {   multiDexEnabled true}depenencies {   compile 'com.android.support:multidex:1.0.1'}AndroidManifest.xml 中的application要实现MultiDexApplication这个类<applicationandroid:name="android.support.multidex.MultiDexApplication"></application>

设置完这三个地方就可以在4点几的手机上正常运行了