Chapter 3 Design to PostgreSql or from database to file system. As an example, a DXP’s application authenticates a user by utilizing the database but it is later decided to go for SSO (single sign-on) using LDAP and SAML. It would be safe if the user were using DAO to access data from the database, as the user only needs to make changes on the data access layer. Java-based projects use JPA and hibernate framework to access data from the databases. You can access data from files, data lakes, NoSQL databases, SQL databases, etc., as shown in Figure 3-18. Figure 3-18. Data Middleware Layer Middleware is an infrastructure that helps to deploy and manage complex business applications. Components of a DXP’s applications may be developed using various programming languages, protocols, and frameworks. Middleware provides the services and helps in implementing NFRs (Figure 3-19) such as transaction concurrency transaction monitoring, security authentication and authorization, transaction logging, transaction auditing, and distributed processing. Figure 3-19. Middleware components 87