/*
* 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.collections;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
import javax.tools.JavaCompiler;
import com.google.common.primitives.Primitives;
import com.mysema.codegen.ECJEvaluatorFactory;
import com.mysema.codegen.Evaluator;
import com.mysema.codegen.EvaluatorFactory;
import com.mysema.codegen.JDKEvaluatorFactory;
import com.mysema.codegen.model.*;
import com.mysema.codegen.support.ClassUtils;
import com.querydsl.core.JoinExpression;
import com.querydsl.core.JoinType;
import com.querydsl.core.QueryMetadata;
import com.querydsl.core.support.CollectionAnyVisitor;
import com.querydsl.core.support.Context;
import com.querydsl.core.types.*;
/**
* {@code DefaultEvaluatorFactory} provides Java source templates for evaluation of {@link CollQuery} queries
*
* @author tiwe
*
*/
public class DefaultEvaluatorFactory {
private final EvaluatorFactory factory;
private final CollQueryTemplates templates;
private final CollectionAnyVisitor collectionAnyVisitor = new CollectionAnyVisitor();
public DefaultEvaluatorFactory(CollQueryTemplates templates) {
this(templates,
Thread.currentThread().getContextClassLoader());
}
public DefaultEvaluatorFactory(CollQueryTemplates templates, EvaluatorFactory factory) {
this.templates = templates;
this.factory = factory;
}
protected DefaultEvaluatorFactory(CollQueryTemplates templates,
URLClassLoader classLoader, JavaCompiler compiler) {
this.templates = templates;
this.factory = new JDKEvaluatorFactory(classLoader, compiler);
}
protected DefaultEvaluatorFactory(CollQueryTemplates templates, ClassLoader classLoader) {
this.templates = templates;
if (classLoader instanceof URLClassLoader) {
this.factory = new JDKEvaluatorFactory((URLClassLoader) classLoader);
} else {
// for OSGi compatibility
this.factory = new ECJEvaluatorFactory(classLoader);
}
}
/**
* Create an Evaluator for the given query sources and projection
*
* @param <T>
* @param metadata query metadata
* @param sources sources of the query
* @param projection projection of the query
* @return evaluator
*/
public <T> Evaluator<T> create(QueryMetadata metadata, List<? extends Expression<?>> sources,
Expression<T> projection) {
final CollQuerySerializer serializer = new CollQuerySerializer(templates);
serializer.append("return ");
if (projection instanceof FactoryExpression<?>) {
serializer.append("(");
serializer.append(ClassUtils.getName(projection.getType()));
serializer.append(")(");
serializer.handle(projection);
serializer.append(")");
} else {
serializer.handle(projection);
}
serializer.append(";");
Map<Object,String> constantToLabel = serializer.getConstantToLabel();
Map<String, Object> constants = getConstants(metadata, constantToLabel);
Class<?>[] types = new Class<?>[sources.size()];
String[] names = new String[sources.size()];
for (int i = 0; i < sources.size(); i++) {
types[i] = sources.get(i).getType();
names[i] = sources.get(i).toString();
}
// normalize types
for (int i = 0; i < types.length; i++) {
if (Primitives.isWrapperType(types[i])) {
types[i] = Primitives.unwrap(types[i]);
}
}
return factory.createEvaluator(serializer.toString(), projection.getType(), names,
types, constants);
}
/**
* Create an Evaluator for the given source and filter
*
* @param <T>
* @param source source of the query
* @param filter filter of the query
* @return evaluator
*/
public <T> Evaluator<List<T>> createEvaluator(QueryMetadata metadata,
Expression<? extends T> source, Predicate filter) {
String typeName = ClassUtils.getName(source.getType());
CollQuerySerializer ser = new CollQuerySerializer(templates);
ser.append("java.util.List<" + typeName + "> rv = new java.util.ArrayList<" + typeName + ">();\n");
ser.append("for (" + typeName + " " + source + " : " + source + "_) {\n");
ser.append(" try {\n");
ser.append(" if (").handle(filter).append(") {\n");
ser.append(" rv.add(" + source + ");\n");
ser.append(" }\n");
ser.append(" } catch (NullPointerException npe) { }\n");
ser.append("}\n");
ser.append("return rv;");
Map<Object,String> constantToLabel = ser.getConstantToLabel();
Map<String, Object> constants = getConstants(metadata, constantToLabel);
Type sourceType = new ClassType(TypeCategory.SIMPLE, source.getType());
ClassType sourceListType = new ClassType(TypeCategory.SIMPLE, Iterable.class, sourceType);
return factory.createEvaluator(
ser.toString(),
sourceListType,
new String[]{source + "_"},
new Type[]{sourceListType},
new Class<?>[]{Iterable.class},
constants);
}
/**
* Create an Evaluator for the given sources and the given optional filter
*
* @param metadata query metadata
* @param joins joins
* @param filter where condition
* @return evaluator
*/
public Evaluator<List<Object[]>> createEvaluator(QueryMetadata metadata,
List<JoinExpression> joins, @Nullable Predicate filter) {
List<String> sourceNames = new ArrayList<String>();
List<Type> sourceTypes = new ArrayList<Type>();
List<Class<?>> sourceClasses = new ArrayList<Class<?>>();
StringBuilder vars = new StringBuilder();
CollQuerySerializer ser = new CollQuerySerializer(templates);
ser.append("java.util.List<Object[]> rv = new java.util.ArrayList<Object[]>();\n");
List<String> anyJoinMatchers = new ArrayList<String>();
// creating context
for (JoinExpression join : joins) {
Expression<?> target = join.getTarget();
String typeName = com.mysema.codegen.support.ClassUtils.getName(target.getType());
if (vars.length() > 0) {
vars.append(",");
}
switch (join.getType()) {
case DEFAULT:
ser.append("for (" + typeName + " " + target + " : " + target + "_) {\n");
vars.append(target);
sourceNames.add(target + "_");
sourceTypes.add(new SimpleType(Types.ITERABLE, new ClassType(TypeCategory.SIMPLE,target.getType())));
sourceClasses.add(Iterable.class);
break;
case INNERJOIN:
case LEFTJOIN:
Operation<?> alias = (Operation<?>) join.getTarget();
boolean colAnyJoin = join.getCondition() != null && join.getCondition().toString().equals("any");
boolean leftJoin = join.getType() == JoinType.LEFTJOIN;
String matcher = null;
if (colAnyJoin) {
matcher = alias.getArg(1).toString() + "_matched";
ser.append("boolean " + matcher + " = false;\n");
anyJoinMatchers.add(matcher);
}
ser.append("for (" + typeName + " " + alias.getArg(1) + " : ");
if (leftJoin) {
ser.append(CollQueryFunctions.class.getName() + ".leftJoin(");
}
if (colAnyJoin) {
Context context = new Context();
Expression<?> replacement = alias.getArg(0)
.accept(collectionAnyVisitor, context);
ser.handle(replacement);
} else {
ser.handle(alias.getArg(0));
}
if (alias.getArg(0).getType().equals(Map.class)) {
ser.append(".values()");
}
if (leftJoin) {
ser.append(")");
}
ser.append(") {\n");
if (matcher != null) {
ser.append("if (!" + matcher + ") {\n");
}
vars.append(alias.getArg(1));
break;
default:
throw new IllegalArgumentException("Illegal join expression " + join);
}
}
// filter
if (filter != null) {
ser.append("try {\n");
ser.append("if (");
ser.handle(filter).append(") {\n");
for (String matcher : anyJoinMatchers) {
ser.append(" " + matcher + " = true;\n");
}
ser.append(" rv.add(new Object[]{" + vars + "});\n");
ser.append("}\n");
ser.append("} catch (NullPointerException npe) { }\n");
} else {
ser.append("rv.add(new Object[]{" + vars + "});\n");
}
// closing context
int amount = joins.size() + anyJoinMatchers.size();
for (int i = 0; i < amount; i++) {
ser.append("}\n");
}
ser.append("return rv;");
Map<Object,String> constantToLabel = ser.getConstantToLabel();
Map<String, Object> constants = getConstants(metadata, constantToLabel);
ClassType projectionType = new ClassType(TypeCategory.LIST, List.class, Types.OBJECTS);
return factory.createEvaluator(
ser.toString(),
projectionType,
sourceNames.toArray(new String[sourceNames.size()]),
sourceTypes.toArray(new Type[sourceTypes.size()]),
sourceClasses.toArray(new Class<?>[sourceClasses.size()]),
constants);
}
private Map<String, Object> getConstants(QueryMetadata metadata,
Map<Object, String> constantToLabel) {
Map<String,Object> constants = new HashMap<String,Object>();
for (Map.Entry<Object,String> entry : constantToLabel.entrySet()) {
if (entry.getKey() instanceof ParamExpression<?>) {
Object value = metadata.getParams().get(entry.getKey());
if (value == null) {
throw new ParamNotSetException((ParamExpression<?>) entry.getKey());
}
constants.put(entry.getValue(), value);
} else {
constants.put(entry.getValue(), entry.getKey());
}
}
return constants;
}
}