PathBuilderFactory.java

/*
 * 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.types.dsl;

import java.util.Map;

import com.google.common.base.CaseFormat;
import com.google.common.collect.Maps;

/**
 * {@code PathBuilderFactory} is a factory class for PathBuilder creation
 *
 * @author tiwe
 *
 */
public final class PathBuilderFactory {

    private final Map<Class<?>, PathBuilder<?>> paths = Maps.newConcurrentMap();

    private final String suffix;

    public PathBuilderFactory() {
        this("");
    }

    public PathBuilderFactory(String suffix) {
        this.suffix = suffix;
    }

    /**
     * Create a new PathBuilder instance for the given type
     *
     * @param type type of expression
     * @return new PathBuilder instance
     */
    @SuppressWarnings("unchecked")
    public <T> PathBuilder<T> create(Class<T> type) {
        PathBuilder<T> rv = (PathBuilder<T>) paths.get(type);
        if (rv == null) {
            rv = new PathBuilder<T>(type, variableName(type));
            paths.put(type, rv);
        }
        return rv;
    }

    private String variableName(Class<?> type) {
        return CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_CAMEL, type.getSimpleName()) + suffix;
    }

}