Hibernate gestion des exceptions

J'ai un peu "complexe" de la question.

Je suis en utilisant Hibernate/JPA, à effectuer des transactions avec un DB.

Je ne suis pas l'administrateur de la base, et un client consomme ma demande, un service web RESTful. Mon problème est que la DB est altérée (pas très souvent, mais il est toujours en évolution). Aussi, le client ne respecte pas toujours l'entrée de mon application (longueur, type, etc.). Lorsque cela arrive, Hibernate génère une exception. L'exception est difficile à traduire et lire le journal, parce qu'il a des exceptions imbriquées et se compose de beaucoup de texte: comme je l'ai dit, très difficile à comprendre.

Je veux savoir si il est possible de gérer les exceptions sur au niveau de l'entité, en jetant peut-être une exception personnalisée.

Je les remercie de votre patience et de votre aide à l'avance.

EDIT:

Au total, j'ai réussi à faire ce que je voulais, ne sais pas si c'est fait le droit chemin.

App.java

package com.mc;  

import org.hibernate.Session;  
import com.mc.stock.Stock;  
import com.mc.util.HibernateUtil;  
import javax.persistence.EntityManager;  

public class App {  

    public static void main(String[] args) {  
        Set<ConstraintViolation<Stock>> violations;
        validator = Validation.buildDefaultValidatorFactory().getValidator();
        Scanner scan = new Scanner(System.in);

        EntityManager em = null;

        System.out.println("Hibernate one to many (Annotation)");
        Session session = HibernateUtil.getSessionFactory().openSession();

        session.beginTransaction();


        Stock stock = new Stock();
        String nextLine = scan.nextLine();
        stock.setStockCode(nextLine.toString());
        nextLine = scan.nextLine();
        stock.setStockName(nextLine.toString());


        violations = validator.validate(stock);
        if (violations.size() > 0) {
            StringBuilder excepcion = new StringBuilder();
            for (ConstraintViolation<Stock> violation : violations) {
                excepcion.append(violation.getMessageTemplate());
                excepcion.append("\n");
            }
            System.out.println(excepcion.toString());
        }
        session.save(stock);
        session.getTransaction().commit();
    }  
}  

FieldMatch.java

package com.mc.constraints;  

import com.mc.constraints.impl.FieldMatchValidator;  

import javax.validation.Constraint;  
import javax.validation.Payload;  
import java.lang.annotation.Documented;  
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;  
import static java.lang.annotation.ElementType.TYPE;  
import java.lang.annotation.Retention;  
import static java.lang.annotation.RetentionPolicy.RUNTIME;  
import java.lang.annotation.Target;  

@Target({TYPE, ANNOTATION_TYPE})  
@Retention(RUNTIME)  
@Constraint(validatedBy = FieldMatchValidator.class)  
@Documented  
public @interface FieldMatch {  

    String message() default "{constraints.fieldmatch}";  

    Class<?>[] groups() default {};  

    Class<? extends Payload>[] payload() default {};  

    String first();  

    String second();  

    @Target({TYPE, ANNOTATION_TYPE})  
    @Retention(RUNTIME)  
    @Documented  
    @interface List {  

        FieldMatch[] value();  
    }  
}  

FieldMatchValidator.java

package com.mc.constraints.impl;  

import javax.validation.ConstraintValidator;  
import javax.validation.ConstraintValidatorContext;  
import com.mc.constraints.FieldMatch;  
import org.apache.commons.beanutils.BeanUtils;  

public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object> {  

    private String firstFieldName;  
    private String secondFieldName;  

    @Override  
    public void initialize(final FieldMatch constraintAnnotation) {  
        firstFieldName = constraintAnnotation.first();  
        secondFieldName = constraintAnnotation.second();  
    }  

    @Override  
    public boolean isValid(final Object value, final ConstraintValidatorContext context) {  
        try {  
            final Object firstObj = BeanUtils.getProperty(value, firstFieldName);  
            final Object secondObj = BeanUtils.getProperty(value, secondFieldName);  

            return firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);  
        } catch (final Exception ignore) {  
            //ignore  
        }  
        return true;  
    }  
}  

Stock.java

package com.mc.stock;  
import com.mc.constraints.FieldMatch;  
import java.io.Serializable;  
import java.util.HashSet;  
import java.util.Set;  
import javax.persistence.Basic;  
import javax.persistence.Column;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.GenerationType;  
import javax.persistence.Id;  
import javax.persistence.NamedQueries;  
import javax.persistence.NamedQuery;  
import javax.persistence.OneToMany;  
import javax.persistence.SequenceGenerator;  
import javax.persistence.Table;  
import javax.xml.bind.annotation.XmlRootElement;  
import javax.xml.bind.annotation.XmlTransient;  
import org.hibernate.annotations.Cascade;  
import org.hibernate.annotations.CascadeType;  
import org.hibernate.validator.constraints.Length;  
@Entity  
@Table(name = "STOCK")  
@XmlRootElement  
@NamedQueries({  
@NamedQuery(name = "Stock.findAll", query = "SELECT s FROM Stock s"),  
@NamedQuery(name = "Stock.findByStockId", query = "SELECT s FROM Stock s WHERE s.stockId = :stockId"),  
@NamedQuery(name = "Stock.findByStockCode", query = "SELECT s FROM Stock s WHERE s.stockCode = :stockCode"),  
@NamedQuery(name = "Stock.findByStockName", query = "SELECT s FROM Stock s WHERE s.stockName = :stockName")})  
@FieldMatch.List({  
@FieldMatch(first = "stockCode", second = "stockName", message = "Code and Stock must have same value")  
})  
public class Stock implements Serializable {  
private static final long serialVersionUID = 1L;  
@Id  
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seq_stock_id")  
@SequenceGenerator(name = "seq_stock_id", sequenceName = "seq_stock_id", initialValue = 1, allocationSize = 1)  
@Basic(optional = false)  
@Column(name = "STOCK_ID", unique = true, nullable = false)  
private Integer stockId;  
@Column(name = "STOCK_CODE")  
private String stockCode;  
@Length(min = 1, max = 20, message = "{wrong stock name length}")  
@Column(name = "STOCK_NAME")  
private String stockName;  
public Stock() {  
}  
public Stock(Integer stockId) {  
this.stockId = stockId;  
}  
public Integer getStockId() {  
return stockId;  
}  
public void setStockId(Integer stockId) {  
this.stockId = stockId;  
}  
public String getStockCode() {  
return stockCode;  
}  
public void setStockCode(String stockCode) {  
this.stockCode = stockCode;  
}  
public String getStockName() {  
return stockName;  
}  
public void setStockName(String stockName) {  
this.stockName = stockName;  
}  
@Override  
public int hashCode() {  
int hash = 0;  
hash += (stockId != null ? stockId.hashCode() : 0);  
return hash;  
}  
@Override  
public boolean equals(Object object) {  
//TODO: Warning - this method won't work in the case the id fields are not set  
if (!(object instanceof Stock)) {  
return false;  
}  
Stock other = (Stock) object;  
if ((this.stockId == null && other.stockId != null) || (this.stockId != null && !this.stockId.equals(other.stockId))) {  
return false;  
}  
return true;  
}  
@Override  
public String toString() {  
return "com.mc.stock.Stock[ stockId=" + stockId + " ]";  
}  
}  

HibernateUtil.java

package com.mc.util;  
import org.hibernate.SessionFactory;  
import org.hibernate.cfg.Configuration;  
public class HibernateUtil {  
private static final SessionFactory sessionFactory = buildSessionFactory();  
private static SessionFactory buildSessionFactory() {  
try {  
//Create the SessionFactory from hibernate.cfg.xml  
return new Configuration().configure().buildSessionFactory();  
} catch (Throwable ex) {  
//Make sure you log the exception, as it might be swallowed  
System.err.println("Initial SessionFactory creation failed." + ex);  
throw new ExceptionInInitializerError(ex);  
}  
}  
public static SessionFactory getSessionFactory() {  
return sessionFactory;  
}  
public static void shutdown() {  
//Close caches and connection pools  
getSessionFactory().close();  
}  
}  

Oracle DB Structure

CREATE TABLE stock  
(  
STOCK_ID  NUMBER(5)  NOT NULL ,  
STOCK_CODE  VARCHAR2(10)  NULL ,  
STOCK_NAME  VARCHAR2(20)  NULL   
);  
ALTER TABLE stock  
add CONSTRAINT PK_STOCK_ID  PRIMARY KEY (STOCK_ID);  
create sequence seq_stock_id   
start with 1   
increment by 1   
nomaxvalue;