1. 使用new關鍵字建立物件

Student stu = new Student();

2. 使用Class類的newInstance方法（反射機制）

// 呼叫無參的構造器建立物件
Student stu = (Student) Class.forName("Student類全限定名").newInstance();　

Student stu = Student.class.newInstance();

3. 使用Constructor類的newInstance方法（反射機制）

class Student {
    private int id;
    
    public
 
 Student(Integer id) {
        this.id = id;
    }
}

// 可以呼叫有引數的和私有的建構函式
Constructor<Student> constructor = Student.class.getConstructor(Integer.class);
       
Student stu = constructor.newInstance(123);

4. 使用Clone方法建立物件

class Student implements Cloneable {

    @Override
    public Object clone
 
() throws CloneNotSupportedException {
        return super.clone();
    }
}

5. 使用(反)序列化機制建立物件

class Student implements Serializable {
   private int id;

   public Student(Integer id) {
       this.id = id;
   }
}

Student stu = new Student(123);

// 寫物件
ObjectOutputStream output = new ObjectOutputStream
 
(new FileOutputStream("student.bin"));
output.writeObject(stu);
output.close();

// 讀物件
ObjectInputStream input = new ObjectInputStream(new FileInputStream("student.bin"));
Student stu = (Student) input.readObject();
System.out.println(stu);