添加exoplayer 2.9.6之后，我遇到了gradle错误，但未构建应用程序。
错误
AGPBI: {"kind":"error","text":"Error converting bytecode to dex:\nCause: Dex cannot parse version 52 byte code.\nThis is caused by library dependencies that have been compiled using Java 8 or above.\nIf you are using the \u0027java\u0027 gradle plugin in a library submodule add \ntargetCompatibility \u003d \u00271.7\u0027\nsourceCompatibility \u003d \u00271.7\u0027\nto that submodule\u0027s build.gradle file.","sources":[{}],"original":"UNEXPECTED TOP-LEVEL EXCEPTION:\njava.lang.RuntimeException: Exception parsing classes\n\tat com.android.dx.command.dexer.Main.processClass(Main.java:775)\n\tat com.android.dx.command.dexer.Main.processFileBytes(Main.java:741)\n\tat com.android.dx.command.dexer.Main.access$1200(Main.java:88)\n\tat com.android.dx.command.dexer.Main$FileBytesConsumer.processFileBytes(Main.java:1683)\n\tat com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)\n\tat com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)\n\tat com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)\n\tat com.android.dx.command.dexer.Main.processOne(Main.java:695)\n\tat com.android.dx.command.dexer.Main.processAllFiles(Main.java:560)\n\tat com.android.dx.command.dexer.Main.runMultiDex(Main.java:376)\n\tat com.android.dx.command.dexer.Main.run(Main.java:290)\n\tat com.android.builder.internal.compiler.DexWrapper.run(DexWrapper.java:54)\n\tat com.android.builder.core.DexByteCodeConverter.lambda$dexInProcess$0(DexByteCodeConverter.java:173)\n\tat java.util.concurrent.FutureTask.run(FutureTask.java:266)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)\n\tat java.lang.Thread.run(Thread.java:745)\nCaused by: com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)\n\tat com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:476)\n\tat com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)\n\tat com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)\n\tat com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)\n\tat com.android.dx.command.dexer.Main.parseClass(Main.java:787)\n\tat com.android.dx.command.dexer.Main.access$1600(Main.java:88)\n\tat com.android.dx.command.dexer.Main$ClassParserTask.call(Main.java:1722)\n\tat com.android.dx.command.dexer.Main.processClass(Main.java:773)\n\t... 16 more\n","tool":"Dex"}AGPBI: {"kind":"error","text":"Error converting bytecode to dex:\nCause: Dex cannot parse version 52 byte code.\nThis is caused by library dependencies that have been compiled using Java 8 or above.\nIf you are using the \u0027java\u0027 gradle plugin in a library submodule add \ntargetCompatibility \u003d \u00271.7\u0027\nsourceCompatibility \u003d \u00271.7\u0027\nto that submodule\u0027s build.gradle file.","sources":[{}],"original":"UNEXPECTED TOP-LEVEL EXCEPTION:\njava.lang.RuntimeException: Exception parsing classes\n\tat com.android.dx.command.dexer.Main.processClass(Main.java:775)\n\tat com.android.dx.command.dexer.Main.processFileBytes(Main.java:741)\n\tat com.android.dx.command.dexer.Main.access$1200(Main.java:88)\n\tat com.android.dx.command.dexer.Main$FileBytesConsumer.processFileBytes(Main.java:1683)\n\tat com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)\n\tat com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)\n\tat com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)\n\tat com.android.dx.command.dexer.Main.processOne(Main.java:695)\n\tat com.android.dx.command.dexer.Main.processAllFiles(Main.java:587)\n\tat com.android.dx.command.dexer.Main.runMultiDex(Main.java:376)\n\tat com.android.dx.command.dexer.Main.run(Main.java:290)\n\tat com.android.builder.internal.compiler.DexWrapper.run(DexWrapper.java:54)\n\tat com.android.builder.core.DexByteCodeConverter.lambda$dexInProcess$0(DexByteCodeConverter.java:173)\n\tat java.util.concurrent.FutureTask.run(FutureTask.java:266)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)\n\tat java.lang.Thread.run(Thread.java:745)\nCaused by: com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)\n\tat com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:476)\n\tat com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)\n\tat com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)\n\tat com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)\n\tat com.android.dx.command.dexer.Main.parseClass(Main.java:787)\n\tat com.android.dx.command.dexer.Main.access$1600(Main.java:88)\n\tat com.android.dx.command.dexer.Main$ClassParserTask.call(Main.java:1722)\n\tat com.android.dx.command.dexer.Main.processClass(Main.java:773)\n\t... 16 more\n","tool":"Dex"}
AGPBI: {"kind":"error","text":"2 errors; aborting","sources":[{}]}
:app:transformClassesWithDexForDebug FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformClassesWithDexForDebug'.
> com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.ide.common.process.ProcessException: Return code 1 for dex process
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.