Java tutorial
/* * Copyright 2015, The Querydsl Team (http://www.querydsl.com/team) * * 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. */ package com.querydsl.jpa.support; import java.util.Map; import org.hibernate.dialect.function.SQLFunction; import org.hibernate.dialect.function.SQLFunctionTemplate; import org.hibernate.type.Type; import com.google.common.collect.Maps; import com.querydsl.core.types.Operator; import com.querydsl.core.types.Ops; import com.querydsl.core.types.Template; import com.querydsl.jpa.hibernate.HibernateUtil; import com.querydsl.sql.SQLTemplates; final class DialectSupport { private DialectSupport() { } public static Map<String, SQLFunction> createFunctions(SQLTemplates templates) { Map<String, SQLFunction> functions = Maps.newHashMap(); functions.put("second", createFunction(templates, Ops.DateTimeOps.SECOND)); functions.put("minute", createFunction(templates, Ops.DateTimeOps.MINUTE)); functions.put("hour", createFunction(templates, Ops.DateTimeOps.HOUR)); functions.put("day", createFunction(templates, Ops.DateTimeOps.DAY_OF_MONTH)); functions.put("week", createFunction(templates, Ops.DateTimeOps.WEEK)); functions.put("month", createFunction(templates, Ops.DateTimeOps.MONTH)); functions.put("year", createFunction(templates, Ops.DateTimeOps.YEAR)); return functions; } public static SQLFunction createFunction(SQLTemplates templates, Operator operator) { Template template = templates.getTemplate(operator); Type type = HibernateUtil.getType(operator.getType()); return new SQLFunctionTemplate(type, convert(template)); } public static String convert(Template template) { StringBuilder builder = new StringBuilder(); for (Template.Element element : template.getElements()) { if (element instanceof Template.AsString) { builder.append("?").append(((Template.AsString) element).getIndex() + 1); } else if (element instanceof Template.ByIndex) { builder.append("?").append(((Template.ByIndex) element).getIndex() + 1); } else if (element instanceof Template.Transformed) { builder.append("?").append(((Template.Transformed) element).getIndex() + 1); } else if (element instanceof Template.StaticText) { builder.append(((Template.StaticText) element).getText()); } else { throw new IllegalStateException("Unsupported element " + element); } } return builder.toString(); } }