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
Pulpdentalsystem
Wednesday, 8 March 2017
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.
Tuesday, 7 March 2017
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.
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