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Example Spring 4 JPA – Data Access Exception Translating

spring example

Posted By: admin juin 26, 2019

This example presents the basic concept of translating data access exceptions in Spring.

The technologies used are :

    – Spring 4.3.18
    – H2 1.3
    – Lombok 1.18
    – JDK 1.80
    – Maven 3.3.9

You can convert this example to an Eclipse IDE project by going to folder where is the pom.xml is, and use the command :

mvn eclipse:eclipse

Inspired from « Beginning Spring » Mert Caliskan, Kenan Sevindik, Rod Johnson (Foreword by), Jürgen Höller (Foreword by).

pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>javaspringexamples.springJPA</groupId>
    <artifactId>springJPAExceptionTranslating</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
 
    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.3.18.RELEASE</version>
        </dependency>
 
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.18.RELEASE</version>
        </dependency>
 
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.1.Final</version>
        </dependency>
 
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>4.3.1.Final</version>
        </dependency>
 
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>1.3.175</version>
        </dependency>
    </dependencies>
</project>
Conf.java
package javaspringexamples.springJPA.ExceptionTranslating;
 
import java.util.HashMap;
import java.util.Map;
 
import javax.sql.DataSource;
 
import org.hibernate.jpa.HibernatePersistenceProvider;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
 
/**
 *
 * @author mounir.sahrani@gmail.com
 *
 */
@Configuration
public class Conf {
 
    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("org.h2.Driver");
        dataSource.setUrl("jdbc:h2:tcp://localhost/~/javaspringexamples");
        dataSource.setUsername("sa");
        dataSource.setPassword("");
        return dataSource;
    }
 
    private Map<String, ?> jpaProperties() {
        Map<String, String> jpaPropertiesMap = new HashMap<String, String>();
        jpaPropertiesMap.put("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
        jpaPropertiesMap.put("hibernate.hbm2ddl.auto", "update");
        return jpaPropertiesMap;
    }
 
    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();
        factoryBean.setPersistenceProviderClass(HibernatePersistenceProvider.class);
        factoryBean.setDataSource(dataSource());
        factoryBean.setPackagesToScan("javaspringexamples.springJPA.ExceptionTranslating");
        factoryBean.setJpaPropertyMap(jpaProperties());
        return factoryBean;
    }
 
    @Bean
    public PersonDAO personDao() {
        PersonDAOImpl dao = new PersonDAOImpl();
        return dao;
    }
 
    @Bean
    public static PersistenceExceptionTranslationPostProcessor persistenceExceptionTranslationPostProcessor() {
        PersistenceExceptionTranslationPostProcessor bean = new PersistenceExceptionTranslationPostProcessor();
        return bean;
    }
 
}
Main.java
package javaspringexamples.springJPA.ExceptionTranslating;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.dao.DataAccessException;
 
/**
 *
 * @author mounir.sahrani@gmail.com
 *
 */
public class Main {
 
    public static void main(String[] args) {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(Conf.class);
 
        PersonDAO dao = (PersonDAO) applicationContext.getBean("personDao");
        // Creating person object
        Person person = new Person();
        person.setFirstName(null);
        person.setLastName("KOLOBANE");
 
        // Spring handles different types of data access exceptions thrown from the data
        // access layer, and translates them into
        // org.springframework.dao.DataAccessException.
        try {
            // Saving person
            dao.save(person);
        } catch (DataAccessException dae) {
            System.out.println("Exception translated by Spring and handled");
        }
    }
}
Person.java
package javaspringexamples.springJPA.ExceptionTranslating;
 
import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
 
/**
 *
 * @author mounir.sahrani@gmail.com
 *
 */
@Entity
public class Person {
 
    @Id
    @GeneratedValue
    private Long id;
 
    @Basic(optional=false)
    private String firstName;
 
    private String lastName;
 
    public Long getId() {
        return id;
    }
 
    public String getFirstName() {
        return firstName;
    }
 
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
 
    public String getLastName() {
        return lastName;
    }
 
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}
PersonDAO.java
package javaspringexamples.springJPA.ExceptionTranslating;
 
/**
 *
 * @author mounir.sahrani@gmail.com
 *
 */
public interface PersonDAO {
    public void save(Person p);
}
PersonDAOImpl.java
package javaspringexamples.springJPA.ExceptionTranslating;
 
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.PersistenceUnit;
 
import org.springframework.stereotype.Repository;
 
/**
 *
 * @author mounir.sahrani@gmail.com
 *
 */
 
@Repository
public class PersonDAOImpl implements PersonDAO {
 
    @PersistenceUnit
    private EntityManagerFactory emf;
 
    public void save(Person p) {
        EntityManager em = emf.createEntityManager();
        EntityTransaction transaction = em.getTransaction();
        transaction.begin();
        em.persist(p);
        transaction.commit();
        em.close();
    }
}

Get the sources of the example from the following GitHub url

Or Download a .zip file