PropertyUtils class of Apache commons beanutils library is very useful and provides you the ability to modify properties of Java object at runtime. PropertyUtils enables you to write highly configurable code where you can provide the name of bean properties and their values from configuration rather than coding in Java program and Apache PropertyUtils can set those properties on Java object at runtime. One popular example of how powerful PropertyUtils can be is display tag which provides a rich tabular display for JSP pages, it uses PropertyUtils class to get values of an object at runtime and then display it.