JAR包未加入APK程序-CFANZ编程社区

前段时间打包遇到了一个问题，jar包不能加入到apk包中。从Eclipse中完全可以，一旦放到服务器端进行打包就出现了问题。

使用ant debug -d得到的信息如下

[dx] trouble processing: [dx] bad class file magic (cafebabe) or version (0033.0000) [dx] ...while parsing com/solo/adsdk/network/a.class [dx] ...while processing com/solo/adsdk/network/a.class [dx] [dx] trouble processing: [dx] bad class file magic (cafebabe) or version (0033.0000) [dx] ...while parsing com/solo/adsdk/network/b.class [dx] ...while processing com/solo/adsdk/network/b.class [dx] [dx] trouble processing: [dx] bad class file magic (cafebabe) or version (0033.0000) [dx] ...while parsing com/solo/adsdk/network/AdsLoader.class [dx] ...while processing com/solo/adsdk/network/AdsLoader.class [dx] [dx] trouble processing: [dx] bad class file magic (cafebabe) or version (0033.0000) [dx] ...while parsing com/solo/adsdk/network/UrlConfig.class [dx] ...while processing com/solo/adsdk/network/UrlConfig.class

[dx] trouble processing:
       [dx] bad class file magic (cafebabe) or version (0033.0000)
       [dx] ...while parsing com/solo/adsdk/network/a.class
       [dx] ...while processing com/solo/adsdk/network/a.class
       [dx]
       [dx] trouble processing:
       [dx] bad class file magic (cafebabe) or version (0033.0000)
       [dx] ...while parsing com/solo/adsdk/network/b.class
       [dx] ...while processing com/solo/adsdk/network/b.class
       [dx]
       [dx] trouble processing:
       [dx] bad class file magic (cafebabe) or version (0033.0000)
       [dx] ...while parsing com/solo/adsdk/network/AdsLoader.class
       [dx] ...while processing com/solo/adsdk/network/AdsLoader.class
       [dx]
       [dx] trouble processing:
       [dx] bad class file magic (cafebabe) or version (0033.0000)
       [dx] ...while parsing com/solo/adsdk/network/UrlConfig.class
       [dx] ...while processing com/solo/adsdk/network/UrlConfig.class

相比到这里，原因不言则明，原来是jar包的编译版本比工程编译的版本不一致，真实的情况是前后比后者编译版本高。经过分析，jar包的编译环境是Java 7，而工程打包的编译环境是Java 6.

如何解决

解决这个问题也简单，不出如下做法

更换成Java 6编译出来的jar包
使用java 7 打包工程。

如何得知jar包编译版本

解压jar包

jar fx android-support-v4.jar

解压后查看当前目录，会多出一个文件夹，这里是名字为android的文件夹。

查看文件信息

11:52 $ file android/support/v4/net/ConnectivityManagerCompat.class android/support/v4/net/ConnectivityManagerCompat.class: compiled Java class data, version 49.0 (Java 1.5)