Introduction to SSH framework in Java language

With the rapid development of the Internet and the popularization of informatization, Java has become one of the most popular development languages. The power and flexibility of Java allow it to be used to develop a variety of applications. From the development of small applications to large enterprise-level applications, Java has a wide range of applications. However, developing large applications requires processing large amounts of data and business logic, and this complexity makes development very difficult. At this time, we need a reliable framework to simplify the development process and improve code quality.

The SSH framework is one of the most commonly used frameworks in the Java language. The SSH framework is an integration of three open source frameworks, Struts2, Spring and Hibernate, hence the name "SSH".

Struts2: is a Web framework used to develop MVC (Model-View-Controller) architecture Web applications. Compared with the previous version of Struts, Struts2 has higher scalability and better performance, and can well meet the development needs of Web applications.

Spring: is an open source framework for building Java enterprise applications. The Spring framework provides a large number of functions, including dependency injection, AOP (aspect-oriented programming), containers, data access, transaction processing, etc. Therefore, the Spring framework is one of the most popular frameworks for Java enterprise development.

Hibernate: It is a Java persistence framework. It is an ORM (Object Relational Mapping) framework that is used to map Java objects into table structures in relational databases. The advantage of the Hibernate framework is that it allows developers to focus more on the development of business logic instead of underlying database operations.

The SSH framework adopts the advantages of these three frameworks while avoiding their shortcomings, and ultimately builds a fully functional development framework. Next, we will introduce the specific functions of each framework in the SSH framework one by one.

Struts2 Framework

The SSH framework is a key part of the SSH framework because it provides an MVC framework for web applications. MVC is a commonly used software architecture method that divides an application into three parts, namely Model, View and Controller. Model represents the data and business logic of the application, View represents the interface of the application, and Controller is responsible for coordinating the interaction between Model and View.

The Action class in the Struts2 framework is the role of the Controller. It is responsible for processing user requests and sending the results to the View part. All requests are handled by the Action proxy class in the Struts2 framework, which is responsible for processing user requests and sending the results to the client.

Another important component of the Struts2 framework is the interceptor. Interceptor is an AOP technology that allows us to further process the request before all Actions are executed. For example, we can log all requests in an interceptor, or perform certain actions before user authentication.

Spring Framework

The Spring framework is another key part of the SSH framework, which provides highly configurable IoC (Inversion of Control) and AOP support. IoC is a programming model that decouples the components of an application and connects them together into a whole.

The IoC container in the Spring framework is an instance of ApplicatinContext, which can manage the creation, configuration and destruction of Beans. A bean is an object managed by the Spring container and can be any Java object. The Spring framework uses IoC containers to build dependencies between application objects, making the program more loosely coupled and easier to maintain and test.

Another important feature of the Spring framework is AOP. AOP is a programming paradigm that allows us to implement common functionality across multiple objects in an application. The Spring AOP framework integrates various concepts and tools required for AOP with the Spring IoC container, making AOP programs easier to implement and maintain.

Hibernate framework

The Hibernate framework is the third component of the SSH framework. It provides ORM technology to map Java objects to relational databases. Each table in the database is mapped to an entity class in the Java class, and each entity class has a data access object (DAO) associated with it, which is responsible for reading or writing data from the database.

Another important feature of the Hibernate framework is the second-level cache. The second-level cache in the Hibernate framework is an optional cache used to store entity objects read during a Hibernate session. This cache can significantly improve application performance because objects can be read directly from the cache at any time without having to perform a database query.

Summary

The SSH framework is a fully functional Java development framework that combines the advantages of the three frameworks Struts2, Spring and Hibernate. The Struts2 framework provides the MVC framework for web applications, the Spring framework provides IoC and AOP support, and the Hibernate framework provides ORM technology and optional second-level cache. Using the SSH framework, developers can take advantage of these powerful tools and frameworks to write high-quality, efficient Java applications.

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