Several ways of instantiating objects in java

1) Create with new() of class

2) Created by the clone method, the class needs to implement the Cloneable interface
User user2 = (User) user1.clone();
3) Use the Class.forName method to obtain the class, and call the newinstance() method of the class

Class<?> cls =null;
User u = null;
try {
cls = Class.forName("com.dao.User");
u = (User)cls.newInstance();
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
}

4) After instantiating an object, serialize it, and then deserialize it, you can also get an object (used in remote communication scenarios)

try{
ObjectOutputStream out = new ObjectOutputStream (new FileOutputStream("D:/objectUser.txt"));
//序列化对象
out.writeObject(user1); //"Kong zi", "13800010001", "Greatwalk"
out.close();
//反序列化对象
ObjectInputStream in = new ObjectInputStream(new FileInputStream("D:/objectUser.txt"));
User user4 = (User) in.readObject();
System.out.println("反序列化user：" + user4);
in.close();
}
catch(ClassNotFoundException e ){
e.printStackTrace();
}
catch(FileNotFoundException e ){
e.printStackTrace();
}
catch(IOException e ){
e.printStackTrace();
}