| /** |
| * 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 com.datatorrent.lib.streamquery.index; |
| |
| import java.util.Map; |
| |
| import javax.validation.constraints.NotNull; |
| |
| |
| /** |
| * <p>An implementation of an index that overrides filter method on basis on columns. </p> |
| * <p> |
| * @displayName Column Index |
| * @category Stream Manipulators |
| * @tags alias |
| * @since 0.3.4 |
| */ |
| public class ColumnIndex implements Index |
| { |
| /** |
| * Column/alias name. |
| */ |
| protected String column = null; |
| protected String alias = null; |
| |
| public ColumnIndex() |
| { |
| } |
| |
| public ColumnIndex(@NotNull String column, String alias) |
| { |
| this.setColumn(column); |
| this.alias = alias; |
| } |
| |
| @Override |
| public void filter(@NotNull Map<String, Object> row, @NotNull Map<String, Object> collect) |
| { |
| String name = getColumn(); |
| if (alias != null) { |
| name = alias; |
| } |
| collect.put(name, row.get(name)); |
| } |
| |
| public String getColumn() |
| { |
| return column; |
| } |
| |
| public void setColumn(String column) |
| { |
| this.column = column; |
| } |
| } |