static final public int MAGIC = 0xCAFEBABE;
// 传递C:\code\hacks\research\com\generationjava\Hack.class
// 假定存在这样一个类
public String getFullyQualifiedName(String filename) throws IOException {
String name = null;
try {
DataInputStream in = new
DataInputStream(new FileInputStream(filename));
if(in.readInt() != MAGIC) {
// 不是一个.class文件
thrownew IOException("Not a class file");
}