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SQL support for Querydsl
There is a newer version: 6.10.1
/*
 * 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.sql;

import com.querydsl.core.types.Expression;
import com.querydsl.core.types.FactoryExpressionBase;
import com.querydsl.core.types.Path;
import com.querydsl.core.types.Projections;
import com.querydsl.core.types.QBean;
import com.querydsl.core.types.Visitor;
import com.querydsl.core.util.ArrayUtils;
import com.querydsl.core.util.CollectionUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * Expression used to project a list of beans
 *
 * @author luis
 */
public class QBeans extends FactoryExpressionBase {

  private static final long serialVersionUID = -4411839816134215923L;

  private final Map, QBean> qBeans;

  private final List> expressions;

  @SuppressWarnings("unchecked")
  public QBeans(RelationalPath... beanPaths) {
    super(Beans.class);
    try {
      final List> listBuilder = new ArrayList<>();
      final Map, QBean> mapBuilder = new HashMap<>();
      for (RelationalPath path : beanPaths) {
        Map> bindings = new LinkedHashMap<>();
        for (Path column : path.getColumns()) {
          bindings.put(column.getMetadata().getName(), column);
          listBuilder.add(column);
        }
        mapBuilder.put(path, Projections.bean((Class) path.getType(), bindings));
      }
      expressions = CollectionUtils.unmodifiableList(listBuilder);
      qBeans = Collections.unmodifiableMap(mapBuilder);
    } catch (Exception e) {
      throw new IllegalStateException(e);
    }
  }

  @Override
  public  R accept(Visitor v, C context) {
    return v.visit(this, context);
  }

  @Override
  public List> getArgs() {
    return expressions;
  }

  @Override
  public Beans newInstance(Object... args) {
    var offset = 0;
    Map, Object> beans = new HashMap<>();
    for (Map.Entry, QBean> entry : qBeans.entrySet()) {
      RelationalPath path = entry.getKey();
      QBean qBean = entry.getValue();
      var argsSize = qBean.getArgs().size();
      var subArgs = ArrayUtils.subarray(args, offset, offset + argsSize);
      beans.put(path, qBean.newInstance(subArgs));
      offset += argsSize;
    }
    return new Beans(beans);
  }
}