jGuard

If you are looking for an easy way to add security to your Java web applications, then jGuard is the library for you. This library offers both authentication and authorization mechanisms that are built over the stable and mature JAAS framework. It is part of the Java J2SE API and has been designed with flexibility in mind.

One of the best things about jGuard is that it offers several different ways to configure the authentication and authorization mechanisms. You can use a relational database, LDAP service or even XML files to set up the security for your application. This level of flexibility makes it easy to integrate jGuard with different types of applications and systems.

It is important to note that jGuard is developed, distributed and licensed under the terms of the GNU Library or Lesser General Public License (LGPL). This means that it can be used, modified and distributed freely as long as any modifications or extensions to the code are also released under the same license.

Overall, if you are looking for an easy-to-use, flexible and secure way to add authentication and authorization to your Java web applications, jGuard is definitely worth checking out.