Question

我尝试了jnaerator SimpleMeaningfulExample （http://code.google.com/p/jnaerator/wiki/SimpleMeaningfulExample）和得到：

$ java -jar jnaerator-0.9.2.jar -library Test Test.h -o . -v
Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad
version number in .class file
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:280)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:374)

...在Mac OS X 10.5.8和Ubuntu 8.04上都运行Java 1.5.0_20。

我在Mac OS X上切换到1.6.0_15并再次尝试并获得：

$ java -jar jnaerator-0.9.2.jar -library Test Test.h -o . -v
Auto-configuring parser...
Nov 20, 2009 5:12:43 PM com.ochafik.lang.jnaerator.JNAeratorConfigUtils getProp
INFO: [environment] JNAERATOR_INCLUDE_PATH=.:/usr/include
Nov 20, 2009 5:12:43 PM com.ochafik.lang.jnaerator.JNAeratorConfigUtils getProp
INFO: [environment] JNAERATOR_FRAMEWORKS_PATH=/System/Library/Frameworks/CoreServices.framework/Versions/Current/Frameworks:/System/Library/Frameworks/ApplicationServices.framework/Versions/Current/Frameworks:/System/Library/Frameworks:/Library/Frameworks:/Local/Library/Frameworks/:/Users/dspitzer/Library/Frameworks
os.arch = x86_64
Nov 20, 2009 5:12:43 PM com.ochafik.lang.jnaerator.JNAerator jnaerate
INFO: Include path : 
        .
        /usr/include
Parsing native headers...
Writing preprocessor output to '_jnaerator.preprocessed.c'
Writing preprocessor macros to '_jnaerator.macros.cpp'
line 0:-1 Failed to match any alternative with token [@-1,0:0='<no text>',<-1>,0:-1]
         File: null:0
        Input: 
         Rule: 1501:1: castExpr returns [Expression expr] : ( '(' tr= mutableTypeRef ')' inner= castExpr | e= unaryExpr );
        Stack: []

line 0:-1 Failed to match any alternative with token [@-1,0:0='<no text>',<-1>,0:-1]
         File: null:0
        Input: 
         Rule: 1501:1: castExpr returns [Expression expr] : ( '(' tr= mutableTypeRef ')' inner= castExpr | e= unaryExpr );
        Stack: []

line 0:-1 Failed to match any alternative with token [@-1,0:0='<no text>',<-1>,0:-1]
         File: null:0
        Input: 
         Rule: 1501:1: castExpr returns [Expression expr] : ( '(' tr= mutableTypeRef ')' inner= castExpr | e= unaryExpr );
        Stack: []

Now parsing 1 text blocks
Normalizing parsed code...
Generating libraries...
JNAeration failed !
java.lang.NullPointerException
        at com.ochafik.lang.jnaerator.TypeConversion.convertExpressionToJava(TypeConversion.java:1391)
        at com.ochafik.lang.jnaerator.TypeConversion.convertExpressionToJava(TypeConversion.java:1223)
        at com.ochafik.lang.jnaerator.DeclarationsConverter.convertVariablesDeclaration(DeclarationsConverter.java:1087)
        at com.ochafik.lang.jnaerator.DeclarationsConverter.convertVariablesDeclaration(DeclarationsConverter.java:1134)
        at com.ochafik.lang.jnaerator.DeclarationsConverter.convertStruct(DeclarationsConverter.java:873)
        at com.ochafik.lang.jnaerator.DeclarationsConverter.outputConvertedStruct(DeclarationsConverter.java:950)
        at com.ochafik.lang.jnaerator.DeclarationsConverter.convertStructs(DeclarationsConverter.java:1055)
        at com.ochafik.lang.jnaerator.JNAerator.generateLibraryFiles(JNAerator.java:1102)
        at com.ochafik.lang.jnaerator.JNAerator.jnaerationCore(JNAerator.java:1322)
        at com.ochafik.lang.jnaerator.JNAerator.jnaerate(JNAerator.java:700)
        at com.ochafik.lang.jnaerator.JNAerator$1.finished(JNAerator.java:613)
        at com.ochafik.lang.jnaerator.JNAeratorCommandLineArgs$ArgsParser.parse(JNAeratorCommandLineArgs.java:127)
        at com.ochafik.lang.jnaerator.JNAerator.main(JNAerator.java:256)

我做错了吗？

更新：我将问题发布到users@jna.dev.java.net（请参阅此主题：https://jna.dev.java.net/servlets/BrowseList?list=users&by=thread&from=2312620），并收到了来自JNAerator项目所有者Olivier Chafik的回复。总结一下：

我在JNAerator
他上传了一个固定的快照构建：http://jnaerator.sourceforge.net/maven/com/jnaerator/jnaerator/0.9.3-SNAPSHOT/
该版本运行得更好，但没有生成TestLibrary.java
我提交了一份错误报告：http://code.google.com/p/jnaerator/issues/detail?id=50

更新＃2： Olivier responded again在意识到缺少TestLibrary.java不是错误之后，因为默认情况下它嵌入在生成的Test.jar文件中。

Answer 1

嗯，你已经自己想出了问题。版本问题。

消息告诉你你的JRE不知道如何在jar中执行类，因为jar中的类有一个比JRE本身更新的版本。

jar文件可能是用java 1.6.x编译的。因此，当您尝试执行它时，JRE会抱怨UnsupportedClassVersionError: Bad version number，因为JRE的版本低于编译的源代码的JDK版本。并且JRE 1.5无法读取jar中类的较新类文件版本。

当您切换到Java 1.6.0_15时，用于运行jar文件的JDK的主要Java版本和用于运行jar的JRE版本是相同的（1.6.x）并且运行正常。

用于生成Java JNA包装器的jnaerator的SimpleMeaningfulExample将不起作用

1 个答案: