添加jar文件后的Android Studio preDexDebug

Question

我有一個自己的框架，我用於課堂上的任務（學校課程，而不是Java類），我把它變成了一個.jar文件，這樣每當我對框架進行更改時，我都可以拖放它進入Android Studio。 在過去的5個左右的類任務中，一切都運行良好，現在突然間，在點擊運行后解析我的.jar時，我遇到了preDexDebug failed錯誤。 我在一個空白項目上測試了這個。 該項目共有2個.jar s：Gson和我自己的jar。 在我拉入我自己的.jar之后，它打印出preDexDebug failed ...我已經在這兩個preDexDebug failed ，我不知道我能做些什么來解決這個問題...

我已經嘗試重建，清理，檢查gradle.build是否有重復項，多次復制項目，以及多次編譯和復制.jar 。

Ubuntu x64與64位Oracle JDK 1.8.0_31。 使用與JDK捆綁在一起的Java

Android Studio輸出：

Configuration on demand is an incubating feature.
:app:preBuild UP-TO-DATE
:app:preDebugBuild UP-TO-DATE
:app:compileDebugNdk UP-TO-DATE
:app:checkDebugManifest
:app:preReleaseBuild UP-TO-DATE
:app:prepareComAndroidSupportAppcompatV72103Library UP-TO-DATE
:app:prepareComAndroidSupportSupportV42103Library UP-TO-DATE
:app:prepareDebugDependencies
:app:compileDebugAidl UP-TO-DATE
:app:compileDebugRenderscript UP-TO-DATE
:app:generateDebugBuildConfig UP-TO-DATE
:app:generateDebugAssets UP-TO-DATE
:app:mergeDebugAssets UP-TO-DATE
:app:generateDebugResValues UP-TO-DATE
:app:generateDebugResources UP-TO-DATE
:app:mergeDebugResources UP-TO-DATE
:app:processDebugManifest UP-TO-DATE
:app:processDebugResources UP-TO-DATE
:app:generateDebugSources UP-TO-DATE
:app:compileDebugJava
:app:preDexDebug
AGPBI: {"kind":"SIMPLE","text":"UNEXPECTED TOP-LEVEL EXCEPTION:","position":{},"original":"UNEXPECTED TOP-LEVEL EXCEPTION:"}
AGPBI: {"kind":"SIMPLE","text":"com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)","position":{},"original":"com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:472)","position":{},"original":"\tat com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:472)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)","position":{},"original":"\tat com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)","position":{},"original":"\tat com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)","position":{},"original":"\tat com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.processClass(Main.java:704)","position":{},"original":"\tat com.android.dx.command.dexer.Main.processClass(Main.java:704)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)","position":{},"original":"\tat com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.access$300(Main.java:83)","position":{},"original":"\tat com.android.dx.command.dexer.Main.access$300(Main.java:83)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)","position":{},"original":"\tat com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)","position":{},"original":"\tat com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)","position":{},"original":"\tat com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)","position":{},"original":"\tat com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.processOne(Main.java:632)","position":{},"original":"\tat com.android.dx.command.dexer.Main.processOne(Main.java:632)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)","position":{},"original":"\tat com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)","position":{},"original":"\tat com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.run(Main.java:246)","position":{},"original":"\tat com.android.dx.command.dexer.Main.run(Main.java:246)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.dexer.Main.main(Main.java:215)","position":{},"original":"\tat com.android.dx.command.dexer.Main.main(Main.java:215)"}
AGPBI: {"kind":"SIMPLE","text":"\tat com.android.dx.command.Main.main(Main.java:106)","position":{},"original":"\tat com.android.dx.command.Main.main(Main.java:106)"}
AGPBI: {"kind":"SIMPLE","text":"...while parsing reactor/communications/ClientEndpointTCP.class","position":{},"original":"...while parsing reactor/communications/ClientEndpointTCP.class"}
AGPBI: {"kind":"SIMPLE","text":"1 error; aborting","position":{},"original":"1 error; aborting"}

Answer 1

事實證明Android SDK尚不支持Java 8（或者沿着這些方面的東西）。 在我的桌面上安裝Oracle JDK 7，並重新編譯我的.jar完全解決了這個問題。

最重要的部分是在產生的錯誤的第二行：“ bad class file magic (cafebabe) or version (0034.0000) ”。 對於52，0x34是十六進制，這意味着二進制文件的目標是支持Java 8的JRE，但Android Studio的系統要求表明需要JDK 7

切換到Oracle JDK 7的步驟：

1. 從Oracle網站下載JDK .tar
2. 解壓到/opt/內容
3. sudo update-alternatives --install /bin/java java /opt/jdk*version*/jre/bin/java 1023
4. sudo update-alternatives --install /bin/javac javac /opt/jdk*version*/bin/javac 1023
5. sudo update-alternatives --install /bin/jar jar /opt/jdk*version*/bin/jar 1023

https://askubuntu.com/questions/56104/how-can-i-install-sun-oracles-proprietary-java-jdk-6-7-8-or-jre