Java对象的深度克隆

这个是非原创的，利用了Java的序列化使得简单的代码就完成了任务，但要注意这个方法性能不是最优的，比调用对象的clone()方法要慢4到10倍吧。

class SerialClone {
    public static  T clone(T x) {
        try {
            return cloneX(x);
        } catch (IOException e) {
            throw new IllegalArgumentException(e);
        } catch (ClassNotFoundException e) {
            throw new IllegalArgumentException(e);
        }
    }

    private static  T cloneX(T x) throws IOException, ClassNotFoundException {
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        CloneOutput cout = new CloneOutput(bout);
        cout.writeObject(x);
        byte[] bytes = bout.toByteArray();

        ByteArrayInputStream bin = new ByteArrayInputStream(bytes);
        CloneInput cin = new CloneInput(bin, cout);

        @SuppressWarnings("unchecked")
                T clone = (T) cin.readObject();
        return clone;
    }

    private static class CloneOutput extends ObjectOutputStream {
        Queue<Class> classQueue = new LinkedList<Class>();

        CloneOutput(OutputStream out) throws IOException {
            super(out);
        }

        @Override
        protected void annotateClass(Class c) {
            classQueue.add(c);
        }

        @Override
        protected void annotateProxyClass(Class c) {
            classQueue.add(c);
        }
    }

    private static class CloneInput extends ObjectInputStream {
        private final CloneOutput output;

        CloneInput(InputStream in, CloneOutput output) throws IOException {
            super(in);
            this.output = output;
        }

        @Override
        protected Class resolveClass(ObjectStreamClass osc)
                throws IOException, ClassNotFoundException {
            Class c = output.classQueue.poll();
            String expected = osc.getName();
            String found = (c == null) ? null : c.getName();
            if (!expected.equals(found)) {
                throw new InvalidClassException("Classes desynchronized: " +
                        "found " + found + " when expecting " + expected);
            }
            return c;
        }

        @Override
        protected Class resolveProxyClass(String[] interfaceNames)
                throws IOException, ClassNotFoundException {
            return output.classQueue.poll();
        }
    }
}