为什么Groovy编译器显然生成1.5版本的Java？

经过一番翻找后,我构建了这段代码来读取该类的前导字节 – 请参阅/ http://en.wikipedia.org/wiki/Java_class_file#General_layout

(更改类的路径以匹配包名称)：

class CompilerVersionSupport {

  public static String getVersion() {
    String classAsPath = 'com/my/organisation/CompilerVersionSupport.class';
    InputStream stream = (new CompilerVersionSupport()).getClass().getClassLoader().getResourceAsStream(classAsPath);
    DataInputStream ins = new DataInputStream (stream)

    assert( ins.readUnsignedShort() == 0xcafe )    
    assert( ins.readUnsignedShort() == 0xbabe )
    int minor = ins.readUnsignedShort();
    int major = ins.readUnsignedShort();
    ins.close();
    int javaVersion = major - 44 
    return "1.$javaVersion"
    }     
}

麻烦的是,它返回1.5.

会发生什么事？

>查尔斯