BeanUtils

BeanUtils is a Java utility library that provides methods for working with JavaBeans. JavaBeans are Java classes that follow a specific design pattern, typically having private fields with public getter and setter methods. The BeanUtils library simplifies common tasks such as copying properties between JavaBeans, converting property values, and accessing nested properties.

One of the core functionalities of BeanUtils is its property manipulation capabilities. It allows developers to easily copy all properties from one bean to another, provided the property names and types are compatible. This can save significant boilerplate code that would otherwise be required to manually set each property. The library also supports copying properties selectively, enabling fine-grained control over which properties are transferred.

BeanUtils also offers robust type conversion features. It can automatically convert property values from one data type to another, such as converting a String to an Integer or a Date to a String. This is particularly useful when dealing with data from various sources, like user input or configuration files, which may need to be mapped to the appropriate types within Java objects.

Furthermore, the library provides support for accessing and manipulating nested properties. This means you can interact with properties of objects that are themselves properties of other objects, using a dot notation similar to how it's done in many scripting languages. For example, you could access a user's address city through a notation like "user.address.city". This feature enhances the convenience of working with complex object graphs.

The BeanUtils library is part of the Apache Commons project and is widely used in Java development for its utility in handling JavaBeans.