Java tutorial
/* * fmgVen - A Convention over Configuration Java ORM Tool * Copyright 2010 Fatih Mehmet Gler * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * under the License. */ package com.fmguler.ven; import com.fmguler.ven.util.Convert; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import javax.sql.DataSource; import org.springframework.beans.BeanWrapper; import org.springframework.beans.BeanWrapperImpl; import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource; import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate; import org.springframework.jdbc.core.namedparam.SqlParameterSource; /** * The main class for data access * @author Fatih Mehmet Gler */ public class Ven { private NamedParameterJdbcTemplate template; private QueryGenerator generator; private QueryMapper mapper; private boolean debug = false; public Ven() { generator = new QueryGenerator(); mapper = new QueryMapper(); } public int count() { return 0; } /** * Get the object with the specified id, of the specified objectClass type. * <p> * By default none of the associations will be retrieved. * To include the object associations (retrieve the object graph) joins * should be specified, e.g. * <code>SomeObject.anotherObject</code> * * @param id the id of the object to be retrieved * @param objectClass the class of the object to be retrieved * @param joins the set of object graphs to be included with the object * @return the retrieved object including specified associations */ public Object get(int id, Class objectClass, Set joins) { String query = generator.generateSelectQuery(objectClass, joins); query += " where 1=1 and " + Convert.toDB(Convert.toSimpleName(objectClass.getName())) + ".id = :___id "; Map paramMap = new HashMap(); paramMap.put("___id", new Integer(id)); if (debug) System.out.println("Ven - SQL: " + query); List result = mapper.list(query, paramMap, objectClass); if (result.isEmpty()) return null; if (result.size() > 1) System.out.println("Ven - WARNING >> get(id) returns more than one row"); return result.get(0); } /** * Get the object with the specified id, of the specified objectClass type. * <p> * By default none of the associations will be retrieved. * To include the object associations (retrieve the object graph) joins * should be specified, e.g. * <code>SomeObject.anotherObject</code> * * @param id the id of the object to be retrieved * @param objectClass the class of the object to be retrieved * @param joins the set of object graphs to be included with the object * @param criteria to filter and order the result according to some criteria * (e.g. for associations) * @return the retrieved object including specified associations */ public Object get(int id, Class objectClass, Set joins, Criteria criteria) { String query = generator.generateSelectQuery(objectClass, joins); query += " where 1=1 and " + Convert.toDB(Convert.toSimpleName(objectClass.getName())) + ".id = :___id " + criteria.criteriaStringToSQL() + " and " + criteria.criteriaToSQL() + criteria.orderStringToSQL(); criteria.getParameters().put("___id", new Integer(id)); if (debug) System.out.println("Ven - SQL: " + query); List result = mapper.list(query, criteria.getParameters(), objectClass); if (result.isEmpty()) return null; if (result.size() > 1) System.out.println("Ven - WARNING >> get(id) returns more than one row"); return result.get(0); } /** * List the objects of the specified objectClass type. * <p> * By default none of the associations will be retrieved. * To include the object associations (retrieve the object graph) joins * should be specified, e.g. * <code>SomeObject.anotherObject</code> * * @param objectClass the class of the objects to be retrieved * @param joins the set of object graphs to be included with objects * @return the list of objects including specified associations */ public List list(Class objectClass, Set joins) { return list(objectClass, joins, new Criteria()); } /** * List the objects of the specified objectClass type, filtering according * to some criteria. * <p> * By default none of the associations will be retrieved. * To include the object associations (retrieve the object graph) joins * should be specified, e.g. * <code>SomeObject.anotherObject</code> * * @param objectClass the class of the objects to be retrieved * @param joins the set of object graphs to be included with objects * @param criteria to filter and order the result according to some criteria * @return the list of objects including the specified associations filtered * according to the specified criteria */ public List list(Class objectClass, Set joins, Criteria criteria) { String query = generator.generateSelectQuery(objectClass, joins); query += " where 1=1 " + criteria.criteriaStringToSQL() + " and " + criteria.criteriaToSQL() + criteria.orderStringToSQL(); if (debug) System.out.println("Ven - SQL: " + query); List result = mapper.list(query, criteria.getParameters(), objectClass); return result; } /** * Save the object. If it has a non null (or non zero) "id" property it will * be updated. * It will be inserted otherwise. * <p> * The object will be saved to a table with the same name as the object, * The fields of object will be mapped to the table fields. * * @param object the object to be saved */ public void save(Object object) { String query = null; if (isObjectNew(object)) { //if this is a new object assign a new id first generateId(object); query = generator.generateInsertQuery(object); } else { query = generator.generateUpdateQuery(object); } //execute the insert/update query SqlParameterSource parameterSource = new BeanPropertySqlParameterSource(object); template.update(query, parameterSource); } /** * Delete the the object with the specified id of the specified objectClass * type * @param id the id of the object to be deleted * @param objectClass the class of the object to be deleted */ public void delete(int id, Class objectClass) { String query = generator.generateDeleteQuery(objectClass); Map parameterMap = new HashMap(); parameterMap.put("id", new Integer(id)); template.update(query, parameterMap); } //-------------------------------------------------------------------------- //PRIVATE METHODS //return true if the object id is zero or null false otherwise private boolean isObjectNew(Object object) throws VenException { BeanWrapper beanWrapper = new BeanWrapperImpl(object); Object objectId = beanWrapper.getPropertyValue("id"); if (objectId == null) return true; if (!(objectId instanceof Integer)) throw new VenException(VenException.EC_GENERATOR_OBJECT_ID_TYPE_INVALID); return ((Integer) objectId).intValue() == 0; } //set new object id private void generateId(Object object) { Integer newObjectId = new Integer( template.queryForInt(generator.generateSequenceQuery(object), new HashMap())); BeanWrapper beanWrapper = new BeanWrapperImpl(object); beanWrapper.setPropertyValue("id", newObjectId); } //-------------------------------------------------------------------------- //SETTERS /** * Set the DataSource to be used to access to the database */ public void setDataSource(DataSource dataSource) { if (dataSource == null) throw new RuntimeException("fmgVen - DataSource cannot be null"); this.template = new NamedParameterJdbcTemplate(dataSource); mapper.setDataSource(dataSource); } /** * Add the domain packages that have corresponding database tables. * <p> * The objects in these packages are considered persistable. * @param domainPackage the package of the entity classes. * @return this instance to allow chaining. */ public Ven addDomainPackage(String domainPackage) { generator.addDomainPackage(domainPackage); mapper.addDomainPackage(domainPackage); return this; } /** * Set debug mode, true will log all debug messages to System.out * <p> * Note: Use debug mode to detect problems only. It is not a general purpose * logging mode. * @param debug set true to enable debug mode */ public void setDebug(boolean debug) { this.debug = debug; generator.setDebug(debug); mapper.setDebug(debug); } //-------------------------------------------------------------------------- //GETTERS /** * @return the underlying query generator, for advanced usage. */ public QueryGenerator getQueryGenerator() { return generator; } /** * @return the underlying query mapper, for advanced usage. */ public QueryMapper getQueryMapper() { return mapper; } }