Hibernate exception handling

[Mark Hero]

I've got a little 'complex'(long) question.

I'm using Hibernate/JPA to make transactions with a DB.

I'm not the DBA, and a client consumes my application, a RESTful web service. My problem is that the DB is altered (not very often, but it still changes). Also, the client does not always respect input for my application (length, type, etc.). When this happens Hibernate throws an exception. The exception is difficult to translate and read from the log, because it has nested exceptions and consists of a lot of text: like I said, very difficult to understand.

I want to know if it's possible to handle exceptions on entity level, throwing maybe a customized exception.

I thank your patience and help in advance.

PD This is the structure of my test app, validating that two fields are equal:

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) {
		EntityManager em = null;

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

		session.beginTransaction();


		Stock stock = new Stock();
		stock.setStockCode("7053");
		stock.setStockName("7055");

		session.save(stock);



		session.getTransaction().commit();
		System.out.println("Done");


	}
}

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 should not be larger than 10 characters")
})
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 = "{zip.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();
    }
}

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;