Java tutorial
/* (c) 2014 Open Source Geospatial Foundation - all rights reserved * (c) 2001 - 2013 OpenPlans * This code is licensed under the GPL 2.0 license, available at the root * application directory. */ package org.geoserver.hibernate; import java.util.Collections; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import org.geoserver.catalog.Info; import org.geoserver.catalog.MetadataMap; import org.geoserver.ows.util.OwsUtils; import org.geotools.util.logging.Logging; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.proxy.HibernateProxy; public class AbstractHibFacade { /** * logging instance */ protected final Logger LOGGER = Logging.getLogger("org.geoserver.hibernate"); protected SessionFactory sessionFactory; public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } public SessionFactory getSessionFactory() { return sessionFactory; } /** Simple wrapper to tell which objects are bindable query parameters */ protected static class QueryParam { Object param; public QueryParam(Object param) { this.param = param; } } protected static QueryParam param(Object param) { return new QueryParam(param); } protected Query query(Object... elems) { final StringBuilder builder = new StringBuilder(); int cnt = 0; for (Object elem : elems) { if (elem instanceof String) { builder.append(elem); } else if (elem instanceof Class) { Class clazz = (Class) elem; ClassMappings map = ClassMappings.fromInterface(clazz); if (map != null) { clazz = map.getImpl(); } builder.append(clazz.getSimpleName()); } else if (elem instanceof QueryParam) { builder.append(":param").append(cnt++); } } Query query = sessionFactory.getCurrentSession().createQuery(builder.toString()); query.setCacheable(true); cnt = 0; for (Object elem : elems) { if (elem instanceof QueryParam) { query.setParameter("param" + (cnt++), ((QueryParam) elem).param); } } return query; } protected Object first(final Query query) { return first(query, true); } protected Object first(final Query query, boolean doWarn) { query.setMaxResults(doWarn ? 2 : 1); query.setCacheable(true); List<?> result = query.list(); if (result.isEmpty()) { return null; } else { //TODO: add a flag to control exception if (result.size() > 1) { throw new RuntimeException("Expected 1 result from " + query + " but got " + result.size()); } // if (doWarn && result.size() > 1) { // LOGGER.log(Level.WARNING, "Found too many items in result", new RuntimeException( // "Trace: Found too many items in query")); // } Object ret = result.get(0); if (ret instanceof HibernateProxy) { HibernateProxy proxy = (HibernateProxy) ret; ret = proxy.getHibernateLazyInitializer().getImplementation(); } if (LOGGER.isLoggable(Level.FINE)) { StringBuilder callerChain = new StringBuilder(); for (StackTraceElement stackTraceElement : new Throwable().getStackTrace()) { if ("first".equals(stackTraceElement.getMethodName())) continue; String cname = stackTraceElement.getClassName(); if (cname.startsWith("org.spring")) continue; cname = cname.substring(cname.lastIndexOf(".") + 1); callerChain.append(cname).append('.').append(stackTraceElement.getMethodName()).append(':') .append(stackTraceElement.getLineNumber()).append(' '); // if(++num==10) break; } LOGGER.fine( "FIRST -->" + ret.getClass().getSimpleName() + " --- " + ret + " { " + callerChain + "}"); } return ret; } } protected <T> List<T> list(Class<T> clazz) { Query query = query("from ", clazz); query.setCacheable(true); List<?> result = query.list(); return Collections.unmodifiableList((List<T>) result); } protected <T extends Info> T persist(T entity) { return persist(entity, true); } protected <T extends Info> T persist(T entity, boolean clearId) { if (clearId) { //hack, clear out id if we are adding a new object Object id = OwsUtils.get(entity, "id"); if (id != null) { OwsUtils.set(entity, "id", null); } } try { MetadataMap md = (MetadataMap) OwsUtils.get(entity, "metadata"); if (md != null) { md.setId(null); } } catch (IllegalArgumentException e1) { } catch (ClassCastException e2) { } sessionFactory.getCurrentSession().persist(entity); return entity; } protected <T extends Info> T merge(T entity) { return (T) sessionFactory.getCurrentSession().merge(entity); } protected void delete(Info entity) { Session session = sessionFactory.getCurrentSession(); Info attached = (Info) session.merge(entity); session.delete(attached); } }