Audit trail in hibernate with new and old values using an Interceptor - database

Question

I can easily log last modified date, modified by etc. However, I need old and new value to be logged too. In the interceptor, I can fire a select before postflush starts executing to get the value of the current record. Then I can run a diff between this record and the new one to see what changed and log that information as old and new values. Is there a better way?
The problem is my object to be modified can be really huge with references to other objects too. Doing a diff can be expensive.
-thanks

Answer 1

Overriding onFlushDirty of EmptyInterceptor(IInterceptor) gives you arrays previousState and currentState. You can use these two arrays to find the oldvalue and newvalue.
look at this example

Answer 2

Why not use audit tables and triggers?

Answer 3

You can try Envers , whichis now part of Hibernate: http://www.jboss.org/envers

Answer 4

I audit this way, but dates are ugly:
persistence.xml: property name="hibernate.ejb.interceptor" value="siapen.jpa.interceptor.MeuInterceptador" />
package siapen.jpa.interceptor;
import java.io.Serializable;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import org.apache.commons.lang3.ObjectUtils;
import org.hibernate.CallbackException;
import org.hibernate.EmptyInterceptor;
import org.hibernate.type.Type;
import siapen.model.BaseEntity;
public class MeuInterceptador extends EmptyInterceptor {
private static final long serialVersionUID = 7853236444153436270L;
private String strSQL = "";
String acao;
#SuppressWarnings("rawtypes")
BaseEntity entity;
String s = "";
#SuppressWarnings("unchecked")
// 1
public boolean onSave(Object obj, Serializable id, Object[] valores, String[] propertyNames, Type[] types)
throws CallbackException {
if (obj instanceof BaseEntity) {
entity = (BaseEntity) obj;
for (int i = 0; i < valores.length; i++) {
if (valores[i] != null && !valores[i].equals("")) {
s += propertyNames[i] + ":" + valores[i];
if (i != valores.length - 1) {
s += "___";
}
}
}
}
return false;
}
#SuppressWarnings("unchecked")
// 1
public boolean onFlushDirty(Object obj, Serializable id, Object[] valoresAtuais, Object[] valoresAnteriores,
String[] propertyNames, Type[] types) throws CallbackException {
if (obj instanceof BaseEntity) {
entity = (BaseEntity) obj;
for (int i = 0; i < valoresAtuais.length; i++) {
if (!ObjectUtils.equals(valoresAtuais[i], valoresAnteriores[i])) {
if (!s.equals("")) {
s += "___";
}
s += propertyNames[i] + "-Anterior:" + valoresAnteriores[i] + ">>>Novo:" + valoresAtuais[i];
}
}
}
return false;
}
#SuppressWarnings("unchecked")
// 1
public void onDelete(Object obj, Serializable id, Object[] state, String[] propertyNames, Type[] types) {
if (obj instanceof BaseEntity) {
entity = (BaseEntity) obj;
}
}
// CHAMADO ANTES DO COMMIT
// 2
#SuppressWarnings("rawtypes")
public void preFlush(Iterator iterator) {
}
// 3
public String onPrepareStatement(String sql) {
acao = "";
if (sql.startsWith("/* update")) {
acao = "update";
} else if (sql.startsWith("/* insert")) {
acao = "insert";
} else if (sql.startsWith("/* delete")) {
acao = "delete";
}
if (acao != null) {
strSQL = sql;
}
return sql;
}
// CHAMADO APÓS O COMMIT
// 4
#SuppressWarnings("rawtypes")
public void postFlush(Iterator iterator) {
if (acao != null) {
try {
if (acao.equals("insert")) {
AuditLogUtil audi = new AuditLogUtil();
audi.LogIt("Salvo", entity, s);
}
if (acao.equals("update")) {
AuditLogUtil audi = new AuditLogUtil();
audi.LogIt("Atualizado", entity, s);
}
if (acao.equals("delete")) {
AuditLogUtil audi = new AuditLogUtil();
audi.LogIt("Deletado", entity, "");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
strSQL = "";
s = "";
}
}
}
}

Answer 5

For those using Envers this can be easily implemented using custom Envers listeners. Also it'll be probably bit cleaner solution.
Implement custom evnvers integrator and register your listeners (look at envers docs )
Implement your Update/Insert listener
public class UpdateEnversListener extends EnversPostUpdateEventListenerImpl {
private static Logger log = LoggerFactory.getLogger(UpdateEnversListener.class);
public UpdateEnversListener(EnversService enversService) {
super(enversService);
}
#Override
public void onPostUpdate(PostUpdateEvent event) {
List<String> auditedProperties = Arrays.asList(event.getPersister().getPropertyNames());
List<Integer> dirtyFieldsIndices = Ints.asList(event.getDirtyProperties());
// In the event you have a object
// In the persister you have indices of fields that changed and also their values
// Do your magic 🦄 stuff here
super.onPostUpdate(event);
}
}