Interpret the technical principles of the Commons Beanutils framework in the Java class library

Commons Beanutils is a sub -item in the Apache Commons project. It provides a set of tools and methods to simplify attribute copy between Java objects and operates object attributes.It enables developers to more easily copy data from one JavaBean to another JavaBean, and can dynamically obtain, set and convert JavaBean's attribute values. The technical principles of commons beanutils are as follows: 1. Reflective mechanism: Beanutils uses Java's reflection mechanism to obtain and set the attributes of JavaBean.By reflection, it can dynamically access and operate the attributes, methods and constructors of the Java class. 2. Properties copy: Beanutils provides a CopyProperties () method, which can copy the attributes of one JavaBean's attribute value to the same name in another JavaBean.It automatically finds the corresponding GETTER and Setter methods based on the attribute name, and uses reflex to obtain and set the attribute value. For example, assuming that there are two JavaBean class Person and User, they have the same attributes (such as name, Age, etc.), you can use Beanutils.copyProperties () method to copy the attribute value of one object to another object: Person person = new Person("John", 25); User user = new User(); BeanUtils.copyProperties(user, person); System.out.println (user.getName ()); // Output "John" System.out.println (user.getage ()); // Output "25" 3. Attribute acquisition and settings: Beanutils provides getproperty () and setproperty () methods, which can dynamically obtain and set the attribute values of JavaBean.Use the getproperty () method to obtain the attribute value through the attribute name, and use the setproperty () method to set the attribute value through the attribute name. User user = new User(); String name = BeanUtils.getProperty(user, "name"); BeanUtils.setProperty(user, "age", 30); 4. Attribute conversion: Beanutils provides some tool methods for type conversion.It can automatically convert the type of type according to the type of the target attribute and convert the value of the source to the target type. For example, assuming that there is a string "25", you can use Beanutils tool method to convert it to an integer type: String ageString = "25"; int age = BeanUtils.convert(ageString, int.class); System.out.println (Age); // Output 25 To sum up, the Commons Beanutils framework provides a set of tool categories and methods for simplifying Java object attribute copy and operation by using the Java's reflection mechanism.It can dynamically obtain, set and convert the attribute values of JavaBean, greatly simplify the work of developers and improve the flexibility and maintenance of the code.