public class DeepCopy {          /**          * 深层拷贝          *           * @param <T>          * @param obj          * @return          * @throws Exception          */          public static <T> T copy(T obj) throws Exception {              //是否实现了序列化接口，即使该类实现了，他拥有的对象未必也有...              if(Serializable.class.isAssignableFrom(obj.getClass())){                  //如果子类没有继承该接口，这一步会报错                  try {                      return copyImplSerializable(obj);                  } catch (Exception e) {                      //这里不处理，会运行到下面的尝试json                  }              }              //如果序列化失败，尝试json序列化方式              if(hasJson()){                  try {                      return copyByJson(obj);                  } catch (Exception e) {                      //这里不处理，下面返回null                  }              }              return null;          }          /**          * 深层拷贝 - 需要类继承序列化接口          * @param <T>          * @param obj          * @return          * @throws Exception          */          @SuppressWarnings("unchecked")          public static <T> T copyImplSerializable(T obj) throws Exception {              ByteArrayOutputStream baos = null;              ObjectOutputStream oos = null;              ByteArrayInputStream bais = null;              ObjectInputStream ois = null;              Object o = null;              //如果子类没有继承该接口，这一步会报错              try {                  baos = new ByteArrayOutputStream();                  oos = new ObjectOutputStream(baos);                  oos.writeObject(obj);                  bais = new ByteArrayInputStream(baos.toByteArray());                  ois = new ObjectInputStream(bais);                  o = ois.readObject();                  return (T) o;              } catch (Exception e) {                  throw new Exception("对象中包含没有继承序列化的对象");              } finally{                  try {                      baos.close();                      oos.close();                      bais.close();                      ois.close();                  } catch (Exception e2) {                      //这里报错不需要处理                  }              }          }          /**          * 是否可以使用json          * @return          */          private static boolean hasJson(){              try {                  Class.forName("net.sf.json.JSONObject");                  return true;              } catch (Exception e) {                  return false;              }          }          /**          * 深层拷贝 - 需要net.sf.json.JSONObject          * @param <T>          * @param obj          * @return          * @throws Exception          */          @SuppressWarnings("unchecked")          public static <T> T copyByJson(T obj) throws Exception {              return (T)JSONObject.toBean(JSONObject.fromObject(obj),obj.getClass());          }      }