Pulp dental entities and components

The Hibernate jargon, an entity is an autonomous object in the persistent Hibernate mechanism that can be manipulated independently of other objects. On the other hand, a component is subordinate to an entity and can only be manipulated with respect to that entity. For example, an Album object can represent an entity; But the Tracks object associated with the Album objects would represent a component of the Album entity if it is assumed that the tracks can only be saved or extracted from the database by the Album object. Unlike J2EE, Hibernate can switch databases

Pulp dental system Hibernate provides transparent persistence

Hibernate provides transparent persistence for older Java objects (POJOs). The only strict requirement for a persistent class is a constructor without argument, not necessarily public. Appropriate behavior in some applications also requires special attention to the equals () and hashCode () methods. [1]

Data object collections are typically stored in Java collection classes, such as implementations of the Set and List interfaces. Java generics, introduced in Java 5, are supported. Hibernate can be configured for collections associated with lazy load. The lazy load is the default value from Hibernate 

Associated objects can be configured to cascade operations from one to another. For example, a parent Album object can be configured to cascade its backup and / or delete operation on its child Track objects.

Pulp dental system uses Hibernate Query Language

Hibernate provides a SQL-inspired language called Hibernate Query Language (HQL) that allows you to write SQL-like queries against Hibernate data objects. Criteria Queries are provided as an object-oriented alternative to HQL. Criteria The query is used to modify objects and provide restriction for objects.

 HQL (Hibernate Query Language) is the object-oriented version of SQL. It generates queries that are independent of the database, so that it is not necessary to write database-specific queries. Without this functionality, modifying the database would require modification of individual SQL queries, resulting in maintenance problems.

Pulp dental system mapping data framework

Mapping Java classes to database tables is implemented by configuring an XML file or by using Java annotations. When using an XML file, Hibernate can generate skeleton source code for persistence classes. This is an auxiliary character when annotations are used. Hibernate can use the XML file or Java annotations to maintain the schema of the database.

There are facilities for organizing one-to-many and several-to-many relationships between classes. In addition to handling associations between objects, Hibernate can also manage reflexive associations in which an object has a one-to-many relationship with other instances of the class type.

Hibernate supports mapping of custom value types. This makes possible the following scenarios:

Replacing the default SQL type when mapping a column to a property.

Mapping Java Enums to columns as if they were regular properties.

Mapping a single property across multiple columns.

Definition: Objects in an object-oriented application follow OOP principles, while background objects follow the principles of standardization of the database, resulting in different representation requirements. This problem is called "object relational impedance mismatch". Mapping is a way to solve the object-relational incompatibility problem.

Mapping informs the ORM tool of the Java class object to store in which database table.

Pulp dental system hibernate application development

Hibernate ORM (Hibernate in brief) is an object-relational mapping tool for the Java programming language. It provides a framework for mapping an object-oriented domain model to a relational database. Hibernate solves the problem of object-relational impedance incompatibility by replacing direct and persistent access to databases with high-level object management functions.

Hibernate is free software that is distributed under the General Public License Lesser GNU 2.1.

The main feature of Hibernate is the mapping of Java classes to database tables and mapping of Java data types to SQL data types. Hibernate also provides data retrieval and retrieval services. It generates SQL calls and frees the developer from manual manipulation and object conversion from the result set.

Pulp dental system spring batch

Spring Batch is a framework for batch processing that provides reusable functions that are essential in processing large volumes of records, including:

Logging / Tracing

Transaction Management

Employment Processing Statistics

Boost employment

It also provides more advanced technical services and capabilities that enable high-volume, high-performance batch jobs through optimization and partitioning techniques. Spring Batch is a framework for batch processing - performing a series of jobs. In Spring Batch, a job consists of several steps and each step consists of a READ-PROCESS-WRITE task or a tasklet.

For the "READ-PROCESS-WRITE" process, this means "reading" the resource data (csv, xml or database), "process" and "write" on other resources (csv, xml and database ). For example, a step can read data from a CSV file, process it, and write it to the database. Spring Batch provides many classes to read / write CSV, XML and database.

For the tasklet task, this means performing a single task, such as deleting resources after or before a step is started or completed.

And the steps can be chained together to function as a job.

Pulp dental system Model-View-Controller Frame

The Spring framework has its own MVC Web application framework, which was not originally intended. The developers of Spring decided to write their own web framework as a reaction to what they perceived as the bad design of the (then) popular Jakarta Struts Web framework, Other frames available. In particular, they found that there was insufficient separation between the presentation and request processing layers and between the application processing layer and the model

Like Struts, Spring MVC is a query-based framework. The framework defines the policy interfaces for all responsibilities that must be addressed by a modern demand-driven framework. The goal of each interface is to be simple and clear so that it is easy for Spring MVC users to write their own implementations if they wish. MVC paves the way for a cleaner front end code. All interfaces are tightly coupled to the Servlet API. This tight coupling to the Servlet API is perceived by some as a failure on the part of Spring's developers to provide high-level abstraction for Web applications [citation needed]. However, this coupling ensures that the functionality of the Servlet API remains available to developers while providing a high abstraction framework to facilitate work with said API.

The DispatcherServlet class is the front-end controller  of the framework and is responsible for delegating control to the different interfaces during the execution phases of an HTTP request.

The most important interfaces defined by Spring MVC and their responsibilities are listed below:

Controller: Between Model and View to handle incoming requests and redirect to the correct answer. It acts as a gateway that directs incoming information. It switches between the entry in the model or the view.

HandlerAdapter: Running objects that handle incoming requests

HandlerInterceptor: Incoming query interception comparable but not equal to Servlet filters (use is optional and not controlled by DispatcherServlet).

HandlerMapping: selection of objects that handle incoming requests (managers) according to any attribute or condition internal or external to these requests

LocaleResolver: resolution and optionally saving the locale of an individual user

MultipartResolver: makes it easy to work with file downloads by wrapping incoming requests

View: Responsible for returning a response to the client. Some requests can go directly to the view without going to the template part; Others can go through all three.

ViewResolver: Select a view based on a logical name for the view (use is not strictly required)

Each strategy interface above has an important responsibility within the overall framework. The abstractions offered by these interfaces are powerful, to allow a set of variations in their implementations, Spring MVC embeds with implementations of all these interfaces and together offers a set of features on top of the Servlet API. However, developers and vendors are free to write other implementations. Spring MVC uses the Java interface java.util.Map as a data-oriented abstraction for the model where the keys are supposed to be string values.

The ease of testing the implementations of these interfaces seems to be an important advantage of the high level of abstraction offered by Spring MVC. DispatcherServlet is tightly coupled to the control container's spring inversion to configure application web layers. However, Web applications can use other parts of the Spring Framework, including the container, and choose not to use Spring MVC.

Pulp dental system Transaction Management Framework

The Spring transaction management framework provides an abstraction mechanism to the Java platform. His abstraction is capable of:

Working with local and global transactions (the local transaction does not require an application server)

Working with nested transactions

Working with backup points

Working in almost all environments of the Java platform

By comparison, JTA supports only nested transactions and global transactions, and requires an application server (and in some cases also deploying applications to an application server)

.

The Spring Framework embeds a PlatformTransactionManager for a number of transaction management strategies:

Transactions managed on a JDBC connection

Managed Transactions on Object-Relational Mapping Work Units

Transactions managed via JTA TransactionManager and UserTransaction

Transactions managed on other resources, such as object databases

Next to this abstraction mechanism, the framework also provides two ways to add transaction management to applications:

Programmatically, using Spring TransactionTemplate

Configuratively, using metadata like XML or Java annotations (@Transactional, etc.)

With the Spring data access framework - which integrates the transaction management framework - it is possible to configure a transactional system through configuration without having to rely on JTA or EJB. The transactional framework also integrates with messaging and caching engines.

Pulp dental System uses Spring Application Development

Pulp Dental System Data Access Frame

Spring's data access framework addresses the common challenges developers encounter when working with databases in applications. Support is provided for all popular Java data access frameworks: JDBC, iBatis / MyBatis, Hibernate, JDO, JPA, Oracle TopLink, Apache OJB and Apache Cayenne, among others.

For all these supported frameworks, Spring provides these features

Resource management - automatic acquisition and release of database resources

Exception handling - translation of the data access exception to a data access hierarchy Spring

Participation in transactions - transparent participation in current transactions

Unpacking resources - retrieving database objects from connection pool envelopes

Abstraction for BLOB and CLOB manipulation

All of these features are available when you use Spring model classes provided for each supported infrastructure. Critics have said that these template classes are intrusive and offer no advantage over using (for example) the Hibernate API directly. [17] [not in the given citation] In response, Spring developers have made it possible to use the Hibernate and JPA APIs directly. However, this requires transparent transaction management because the application code no longer assumes responsibility for obtaining and closing database resources and does not support exception translation.

With Spring's transaction management, its data access framework offers a flexible abstraction to work with data access frameworks. Spring Framework does not have a common data access API; Instead, the total power of the supported APIs is retained intact. Spring Framework is the only framework available in Java that provides managed data access environments outside of an application server or container.

When using Spring to manage transactions with Hibernate, the following beans can be configured:

·        data source like com.mchange.v2.c3p0.ComboPooledDataSource or org.apache.commons.dbcp.BasicDataSource

·       SessionFactory as org.springframework.orm.hibernate3.LocalSessionFactoryBean with a DataSource attribute

·         HibernateProperties like org.springframework.beans.factory.config.PropertiesFactoryBean

·          TransactionManager like org.springframework.orm.hibernate3.HibernateTransactionManager with a SessionFactory attribute