class文件转dex文件错误Caused by: com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe)...

C:\>javac HelloWorld.java

C:\>dx --dex --output=HelloWorld.dex HelloWorld.class

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.RuntimeException: Exception parsing classes
        at com.android.dx.command.dexer.Main.processClass(Main.java:752)
        at com.android.dx.command.dexer.Main.processFileBytes(Main.java:718)
        at com.android.dx.command.dexer.Main.access$1200(Main.java:85)
        at com.android.dx.command.dexer.Main$FileBytesConsumer.processFileBytes(Main.java:1645)
        at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:170)
        at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
        at com.android.dx.command.dexer.Main.processOne(Main.java:672)
        at com.android.dx.command.dexer.Main.processAllFiles(Main.java:574)
        at com.android.dx.command.dexer.Main.runMonoDex(Main.java:311)
        at com.android.dx.command.dexer.Main.run(Main.java:277)
        at com.android.dx.command.dexer.Main.main(Main.java:245)
        at com.android.dx.command.Main.main(Main.java:106)
Caused by: com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000)
        at com.android.dx.cf.direct.DirectClassFile.parse0(DirectClassFile.java:472)
        at com.android.dx.cf.direct.DirectClassFile.parse(DirectClassFile.java:406)
        at com.android.dx.cf.direct.DirectClassFile.parseToInterfacesIfNecessary(DirectClassFile.java:388)
        at com.android.dx.cf.direct.DirectClassFile.getMagic(DirectClassFile.java:251)
        at com.android.dx.command.dexer.Main.parseClass(Main.java:764)
        at com.android.dx.command.dexer.Main.access$1500(Main.java:85)
        at com.android.dx.command.dexer.Main$ClassParserTask.call(Main.java:1684)
        at com.android.dx.command.dexer.Main.processClass(Main.java:749)
        ... 11 more
1 error; aborting

原因：如果你在执行class文件转dex文件时出现了这个错误，那么可能你的jdk版本高于1.6导致。

办法：在你编译时使用javac -target 1.6 -source 1.6 HelloWorld.java，而不是javac HelloWorld.java，指定编译版本为1.6，编译class文件。