/*
* 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.core.alias;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
import com.google.common.base.CaseFormat;
import com.querydsl.core.types.EntityPath;
import com.querydsl.core.types.Expression;
import com.querydsl.core.types.Path;
import com.querydsl.core.types.dsl.*;
/**
* {@code Alias} provides alias factory methods
*
* <p>Example:</p>
*
* <pre>{@code
* Employee e = alias(Employee.class, "e");
* for (String name : query.from($(e),employees)
* .where($(e.getDepartment().getId()).eq(1001))
* .list($(e.getName()))) {
* System.out.println(name);
* }}</pre>
*
* <p>using the following static imports</p>
*
* <pre>{@code
* import static com.mysema.query.alias.Alias.$;
* import static com.mysema.query.alias.Alias.alias;
* }</pre>
*
* @author tiwe
*/
@SuppressWarnings("PMD")
public final class Alias {
private static final AliasFactory aliasFactory = new AliasFactory(new DefaultPathFactory(), new DefaultTypeSystem());
private static final SimplePath<Object> it = Expressions.path(Object.class, "it");
// exclude $-methods from Checkstyle checks
//CHECKSTYLE:OFF
/**
* Convert the given alias to an expression
*
* @param <D>
* @return expression
*/
public static <D extends Expression<?>> D $() {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
public static <D> ArrayPath<D[], D> $(D[] arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<BigDecimal> $(BigDecimal arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<BigInteger> $(BigInteger arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static BooleanPath $(Boolean arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Byte> $(Byte arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <T>
* @return expression
*/
public static <T extends Enum<T>> EnumPath<T> $(T arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
public static <D> CollectionPath<D, SimpleExpression<D>> $(Collection<D> arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
public static <D extends Comparable<?>> ComparablePath<D> $(D arg) {
return Alias.getPath(arg);
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Double> $(Double arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Float> $(Float arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Integer> $(Integer arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static DatePath<java.sql.Date> $(java.sql.Date arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static DateTimePath<java.util.Date> $(java.util.Date arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
public static <D> ListPath<D, SimpleExpression<D>> $(List<D> arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Long> $(Long arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <K>
* @param <V>
* @return expression
*/
public static <K, V> MapPath<K, V, SimpleExpression<V>> $(Map<K, V> arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
public static <D> SetPath<D, SimpleExpression<D>> $(Set<D> arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static NumberPath<Short> $(Short arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static StringPath $(String arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static TimePath<Time> $(Time arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @return expression
*/
public static DateTimePath<Timestamp> $(Timestamp arg) {
return aliasFactory.getCurrentAndReset();
}
/**
* Convert the given alias to an expression
*
* @param arg alias
* @param <D>
* @return expression
*/
@SuppressWarnings("unchecked")
@Nullable
public static <D> EntityPathBase<D> $(D arg) {
EntityPathBase<D> rv = aliasFactory.getCurrentAndReset();
if (rv != null) {
return rv;
} else if (arg instanceof EntityPath<?>) {
return (EntityPathBase<D>) arg; //NOSONAR
} else if (arg instanceof ManagedObject) {
return (EntityPathBase<D>) ((ManagedObject) arg).__mappedPath();
} else {
return null;
}
}
@SuppressWarnings("unchecked")
@Nullable
private static <D, P extends Path<D>> P getPath(D arg) {
P rv = aliasFactory.getCurrentAndReset();
if (rv != null) {
return rv;
} else if (arg instanceof Path<?>) {
return (P) arg;
} else if (arg instanceof ManagedObject) {
return (P) ((ManagedObject) arg).__mappedPath();
} else {
return null;
}
}
//CHECKSTYLE:ON
/**
* Create a new alias proxy of the given type
*
* @param cl type of the alias
* @return alias instance
*/
public static <A> A alias(Class<A> cl) {
return alias(cl, CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_CAMEL, cl.getSimpleName()));
}
/**
* Create a new alias proxy of the given type for the given expression
*
* @param cl type of the alias
* @param expr underlying expression
* @return alias instance
*/
public static <A> A alias(Class<A> cl, Expression<? extends A> expr) {
return aliasFactory.createAliasForExpr(cl, expr);
}
/**
* Create a new alias proxy of the given type for the given variable
*
* @param cl type of the alias
* @param var variable name for the underlying expression
* @return alias instance
*/
public static <A> A alias(Class<A> cl, String var) {
return aliasFactory.createAliasForVariable(cl, var);
}
/**
* Convert the given alias to an expression
*
* @param <D>
* @param arg alias instance
* @return underlying expression
*/
@SuppressWarnings("unchecked")
public static <D> Expression<D> getAny(D arg) {
Expression<D> current = aliasFactory.getCurrentAndReset();
if (current != null) {
return current;
} else if (arg instanceof ManagedObject) {
return (Expression<D>) ((ManagedObject) arg).__mappedPath();
} else {
throw new IllegalArgumentException("No path mapped to " + arg);
}
}
/**
* Reset the alias
*/
public static void resetAlias() {
aliasFactory.reset();
}
/**
* Return the default variable
*
* @param <D>
* @return expression
*/
@SuppressWarnings("unchecked")
public static <D> SimplePath<D> var() {
return (SimplePath<D>) it;
}
/**
* Create a new variable path
*
* @param arg alias
* @param <D>
* @return expression
*/
@SuppressWarnings("unchecked")
public static <D extends Comparable<?>> ComparablePath<D> var(D arg) {
return Expressions.comparablePath((Class<D>) arg.getClass(), "var" + arg);
}
/**
* Create a new variable path
*
* @param arg alias
* @param <D>
* @return expression
*/
@SuppressWarnings("unchecked")
public static <D extends Number & Comparable<D>> NumberPath<D> var(D arg) {
return Expressions.numberPath((Class<D>) arg.getClass(), "var" + arg.getClass().getSimpleName() + arg);
}
/**
* Create a new variable path
*
* @param arg alias
* @param <D>
* @return expression
*/
@SuppressWarnings("unchecked")
public static <D> EntityPathBase<D> var(D arg) {
String var = "var" + arg.getClass().getSimpleName() + "_" + arg.toString().replace(' ', '_');
return new PathBuilder<D>((Class) arg.getClass(), var);
}
/**
* Create a new variable path
*
* @param arg alias
* @return expression
*/
public static StringPath var(String arg) {
return Expressions.stringPath(arg.replace(' ', '_'));
}
private Alias() { }
}