| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.openjpa.persistence.criteria; |
| |
| import java.lang.reflect.Field; |
| import java.lang.reflect.Method; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Set; |
| |
| import javax.persistence.criteria.CriteriaBuilder; |
| import javax.persistence.criteria.Expression; |
| import javax.persistence.criteria.Path; |
| import javax.persistence.criteria.Predicate; |
| import javax.persistence.metamodel.Attribute; |
| import javax.persistence.metamodel.ManagedType; |
| import javax.persistence.metamodel.SingularAttribute; |
| |
| import org.apache.openjpa.enhance.Reflection; |
| |
| /** |
| * An expression for query-by-example. |
| * |
| * @author Pinaki Poddar |
| * |
| */ |
| class CompareByExample<T> extends PredicateImpl { |
| |
| CompareByExample(CriteriaBuilder builder, ManagedType<T> type, |
| Path<T> from, T instance, ComparisonStyle style, |
| Attribute<?, ?>... excludes) { |
| super(extractOperator(style)); |
| List<Attribute<?, ?>> excludeAttr = excludes == null |
| ? new ArrayList<>() : Arrays.asList(excludes); |
| |
| Set<SingularAttribute<? super T, ?>> attrs = type.getSingularAttributes(); |
| for (SingularAttribute<? super T, ?> attr : attrs) { |
| if (excludeAttr.contains(attr) |
| || (style.excludeIdentity() && attr.isId()) |
| || (style.excludeVersion() && attr.isVersion())) { |
| continue; |
| } |
| |
| Object value = extractValue(instance, attr); |
| if ((style.excludeNull() && value == null) |
| || (style.excludeDefault() && isDefaultValue(attr.getJavaType(), value))) |
| continue; |
| |
| Predicate p = null; |
| if (value == null) { |
| p = from.get(attr).isNull(); |
| this.add(p); |
| continue; |
| } |
| if (attr.isAssociation()) { |
| p = new CompareByExample(builder, (ManagedType<?>)attr.getType(), |
| from.get(attr), value, style, excludes); |
| } else if (attr.getJavaType() == String.class) { |
| Expression<String> s = from.get(attr).as(String.class); |
| switch (style.getStringComparsionMode()) { |
| case EXACT : p = builder.equal(s, value); |
| break; |
| case CASE_INSENSITIVE : p = builder.equal(builder.upper(s), value.toString()); |
| break; |
| case LIKE: p = builder.like(s, value.toString()); |
| break; |
| } |
| } else { |
| p = builder.equal(from.get(attr), value); |
| } |
| this.add(p); |
| } |
| } |
| |
| Object extractValue(T instance, SingularAttribute<? super T, ?> attr) { |
| Class<?> cls = instance.getClass(); |
| Method getter = Reflection.findGetter(cls, attr.getName(), false); |
| if (getter != null) |
| return Reflection.get(instance, getter); |
| Field field = Reflection.findField(cls, attr.getName(), false); |
| if (field != null) |
| return Reflection.get(instance, field); |
| return null; |
| } |
| |
| boolean isDefaultValue(Class<?> cls, Object val) { |
| if (val == null) { |
| return true; |
| } |
| if (cls == Boolean.class || cls == boolean.class) { |
| return Boolean.FALSE.equals(val); |
| } else if (cls == Character.class || cls == char.class) { |
| return (Character) val == 0; |
| } else if (cls == Byte.class || cls == byte.class |
| || cls == Double.class || cls == double.class |
| || cls == Float.class || cls == float.class |
| || cls == Long.class || cls == long.class |
| || cls == Integer.class || cls == int.class |
| || cls == Short.class || cls == short.class) { |
| return ((Number) val).intValue() == 0; |
| } else if (cls == String.class) { |
| return "".equals(val); |
| } else { |
| return false; |
| } |
| } |
| |
| static <T> BooleanOperator extractOperator(ComparisonStyle style) { |
| return style == null ? BooleanOperator.AND : style.isDisjunction() ? BooleanOperator.OR : BooleanOperator.AND; |
| } |
| } |