Shulou(Shulou.com)06/01 Report--

1. The status of Hibernate in SSH

SSH serial number technology functions 1Struts application layer framework technology based on mvc mode! 2Spring creates objects, handles object dependencies, and integrates frameworks! 3Hibernate is based on the persistence layer framework (used by the data access layer)!

2. How is the code of the DAO layer written?

(1) manipulate XML data

(2) using Jdbc technology

A) the original jdbc operation, Connection/Statement/ResultSet

B) customize a persistence layer framework that encapsulates a common approach to dao

C) DbUtils component, lightweight dao component

D) Hibernate technology [hibernate finally executes jdbc code! ]

3. ORM and Hibernate

3.1Concepts of ORM

O, Object object

R, Realtion relationship (relational database: MySQL, Oracle …)

MMagneMapping mapping

ORM, object-relational mapping!

ORM, what's the problem?

Storage: save the data of an object directly to the database

Get: get an object directly from the database

To achieve the above 2 points, there must be a mapping!

3.2.The relationship between Hibernate and ORM

Hibernate is the implementation of ORM!

4. Three aspects of component learning

1. Source code, import jar file

2. Configure (.xml or .properties)

3 、 API

5. Getting started with Hibernate

Hibernate development steps

(1) download the source code

Version: hibernate-distribution-3.6.0.Final, download address as follows:

Https://sourceforge.net/projects/hibernate/files/hibernate3/3.6.0.Final/

Select the file of 141.0MB, which is in .zip format, while the following file is in .gz format.

After decompression, its source code is located in the hibernate-distribution-3.6.0.Final\ project\ core\ src directory

(2) introduce jar file

A) hibernate3.jar (core document)

Located in the hibernate-distribution-3.6.0.Final directory

B) required (6 jar that must be introduced)

Located in the hibernate-distribution-3.6.0.Final\ lib\ required directory

C) jpa directory

Located in the hibernate-distribution-3.6.0.Final\ lib\ jpa directory

D) Database driver package (I use mysql driver package)

(3) write objects and their mapping.

A) Employee.java object

Import java.util.Date;public class Employee {private int empId; private String empName; private Date workDate; public int getEmpId () {return empId;} public void setEmpId (int empId) {this.empId = empId;} public String getEmpName () {return empName } public void setEmpName (String empName) {this.empName = empName;} public Date getWorkDate () {return workDate;} public void setWorkDate (Date workDate) {this.workDate = workDate;}}

B) Mapping of Employee.hbm.xml objects (mapping file)

(.hbm may be an abbreviation for hibernate mapping)

(4) main configuration file src/hibernate.cfg.xml

A) Database connection configuration

B) load the mapping used (* .hbm.xml)

Com.mysql.jdbc.Driver jdbc:mysql:///test root root org.hibernate.dialect.MySQL5Dialect true true update

(5) testing

Package com.rk.hibernate.a_hello;import java.util.Date;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.classic.Session;public class App {public static void main (String [] args) {/ / object Employee emp = new Employee (); emp.setEmpName ("Zhang San") Emp.setWorkDate (new Date ()); / * * main idea: Configuration-- > SessionFactory-- > Session * details: Session-- > Transaction. Transaction must be created by session, otherwise it cannot be saved. * / / get the management class object Configuration config = new Configuration (); config.configure (); / / create the session factory object SessionFactory sessionFactory = config.buildSessionFactory () that loads the configuration file / / create session (representing a session connected to the database) Session session = sessionFactory.openSession (); / / Open transaction Transaction transaction = session.beginTransaction (); / / Save data session.save (emp) / / commit transaction transaction.commit (); / / close session.close (); sessionFactory.close (); System.out.println ("Over");}}

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