generalized java service using hibernate envers to audit changes done by user in database in web application - spring

Question

public class App
{
public static void main( String[] args )
{
//test insert
tx = session.beginTransaction();
System.out.println("Maven + Hibernate + MySQL");
// Session session = HibernateUtil.getSessionFactory().openSession();
//session.beginTransaction();
Stock stock = new Stock();
stock.setStockCode("7000");
stock.setStockName("z");
session.saveOrUpdate(stock);
}
Stock.java
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;
import javax.persistence.UniqueConstraint;
import com.warp.intercept.*;
/**
* Stock generated by hbm2java
*/
#Entity
#Table(name = "stock", catalog = "mkyong", uniqueConstraints = {
#UniqueConstraint(columnNames = "STOCK_NAME"),
#UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable, IAuditLog {
private Integer stockId;
private String stockCode;
private String stockName;
public Stock() {
}
public Stock(String stockCode, String stockName) {
this.stockCode = stockCode;
this.stockName = stockName;
}
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "STOCK_ID", unique = true, nullable = false)
public Integer getStockId() {
return this.stockId;
}
public void setStockId(Integer stockId) {
this.stockId = stockId;
}
#Column(name = "STOCK_CODE", unique = true, nullable = false, length = 10)
public String getStockCode() {
return this.stockCode;
}
public void setStockCode(String stockCode) {
this.stockCode = stockCode;
}
#Column(name = "STOCK_NAME", unique = true, nullable = false, length = 20)
public String getStockName() {
return this.stockName;
}
public void setStockName(String stockName) {
this.stockName = stockName;
}
I have a java web application, I want to create audit logs in database for all the database changes like(column changed, value changed in column, userid, timestamp and some other fields). I want to create a generalized service which has methods exposed for such operations and I can access them from any other component in the application. As far as I have read, this can be done through hibernate envers or Spring AOP. Can you please suggest and provde me with an example which I can utilize to extend it further.
P.S. : I don't want to use trigger based logging for auditing database changes
Suppose this is my entiity stock; I am performing some simple save operations on the stock thru hibernate. Suppose, I have a main method and I perform below mentioned operation

Answer 1

Well, I am not a Spring or Hibernate user, so I do not know what exactly you need to capture. But if it is just the setters of any #Entity-annotated class, the whole thing would basically look like this:
Driver application:
package de.scrum_master.app;
import org.hibernate.Session;
import org.hibernate.Transaction;
public class Application {
public static void main(String[] args) {
System.out.println("Maven + Hibernate + MySQL");
// Session session = HibernateUtil.getSessionFactory().openSession();
// Transaction tx = session.beginTransaction();
Stock stock = new Stock();
stock.setStockCode("7000");
stock.setStockName("z");
// session.saveOrUpdate(stock);
}
}
Auditing aspect:
package de.scrum_master.aspect;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
#Aspect
public class DBAuditAspect {
#Before("execution(public void set*(*)) && #target(javax.persistence.Entity) && args(setterArgument)")
public void entitySetterExecution(Object setterArgument, JoinPoint thisJoinPoint) {
System.out.println(thisJoinPoint + " - " + setterArgument);
}
}
Console output:
Maven + Hibernate + MySQL
execution(void de.scrum_master.app.Stock.setStockCode(String)) - 7000
execution(void de.scrum_master.app.Stock.setStockName(String)) - z
The more general question of how to set up and use Spring AOP is explained in the documentation, chapter 9. Aspect Oriented Programming with Spring.