Java tutorial
/* * #%L * ACS AEM Commons Bundle * %% * Copyright (C) 2017 Adobe * %% * 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. * #L% */ package com.adobe.acs.commons.data; import aQute.bnd.annotation.ProviderType; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Array; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import java.util.Optional; import java.util.regex.Pattern; import java.util.stream.Collectors; import java.util.stream.StreamSupport; import org.apache.commons.lang3.StringUtils; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.xssf.usermodel.XSSFSheet; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import org.apache.sling.api.request.RequestParameter; /** * Simple abstraction of reading a single spreadsheet of values. Expects a * header row of named columns (case-sensitive) If provided, will also filter * data rows missing required columns to prevent processing errors. */ @ProviderType public class Spreadsheet { public static final String DEFAULT_DELIMITER = ","; public static final String ROW_NUMBER = "~~ROWNUM~~"; private String fileName = "unknown"; private int rowCount; private transient List<Map<String, CompositeVariant>> dataRows; private final List<String> requiredColumns; private Map<String, Class> headerTypes; private List<String> headerRow; private final Map<String, String> delimiters; private boolean enableHeaderNameConversion = true; /** * Simple constructor used for unit testing purposes * * @param convertHeaderNames If true, header names are converted * @param headerArray List of strings for header columns */ public Spreadsheet(boolean convertHeaderNames, String... headerArray) { this.enableHeaderNameConversion = convertHeaderNames; headerTypes = Arrays.stream(headerArray) .collect(Collectors.toMap(this::convertHeaderName, this::detectTypeFromName)); headerRow = Arrays.asList(headerArray); requiredColumns = Collections.EMPTY_LIST; dataRows = new ArrayList<>(); delimiters = new HashMap<>(); } public Spreadsheet(boolean convertHeaderNames, InputStream file, String... required) throws IOException { delimiters = new HashMap<>(); this.enableHeaderNameConversion = convertHeaderNames; if (required == null || required.length == 0) { requiredColumns = Collections.EMPTY_LIST; } else { requiredColumns = Arrays.stream(required).map(this::convertHeaderName).collect(Collectors.toList()); } parseInputFile(file); } public Spreadsheet(boolean convertHeaderNames, RequestParameter file, String... required) throws IOException { this(convertHeaderNames, file.getInputStream(), required); fileName = file.getFileName(); } public Spreadsheet(InputStream file, String... required) throws IOException { this(true, file, required); } public Spreadsheet(RequestParameter file, String... required) throws IOException { this(true, file, required); } /** * Parse out the input file synchronously for easier unit test validation * * @return List of files that will be imported, including any renditions * @throws IOException if the file couldn't be read */ private void parseInputFile(InputStream file) throws IOException { XSSFWorkbook workbook = new XSSFWorkbook(file); final XSSFSheet sheet = workbook.getSheetAt(0); rowCount = sheet.getLastRowNum(); final Iterator<Row> rows = sheet.rowIterator(); Row firstRow = rows.next(); headerRow = readRow(firstRow).stream().map(v -> v != null ? convertHeaderName(v.toString()) : null) .collect(Collectors.toList()); headerTypes = readRow(firstRow).stream().map(Variant::toString) .collect(Collectors.toMap(this::convertHeaderName, this::detectTypeFromName, this::upgradeToArray)); Iterable<Row> remainingRows = () -> rows; dataRows = StreamSupport.stream(remainingRows.spliterator(), false).map(this::buildRow) .filter(Optional::isPresent).map(Optional::get).collect(Collectors.toList()); } private List<Variant> readRow(Row row) { Iterator<Cell> iterator = row.cellIterator(); List<Variant> rowOut = new ArrayList<>(); while (iterator.hasNext()) { Cell c = iterator.next(); while (c.getColumnIndex() > rowOut.size()) { rowOut.add(null); } Variant val = new Variant(c); rowOut.add(val.isEmpty() ? null : val); } return rowOut; } @SuppressWarnings("squid:S3776") private Optional<Map<String, CompositeVariant>> buildRow(Row row) { Map<String, CompositeVariant> out = new LinkedHashMap<>(); out.put(ROW_NUMBER, new CompositeVariant(row.getRowNum())); List<Variant> data = readRow(row); boolean empty = true; for (int i = 0; i < data.size() && i < getHeaderRow().size(); i++) { String colName = getHeaderRow().get(i); if (colName != null && data.get(i) != null && !data.get(i).isEmpty()) { empty = false; if (!out.containsKey(colName)) { out.put(colName, new CompositeVariant(headerTypes.get(colName))); } if (headerTypes.get(colName).isArray()) { String[] values = data.get(i).toString() .split(Pattern.quote(delimiters.getOrDefault(colName, DEFAULT_DELIMITER))); for (String value : values) { if (value != null && !value.isEmpty()) { out.get(colName).addValue(value.trim()); } } } else { out.get(colName).addValue(data.get(i)); } } } if (empty || (!requiredColumns.isEmpty() && !out.keySet().containsAll(requiredColumns))) { return Optional.empty(); } else { return Optional.of(out); } } /** * @return the fileName */ public String getFileName() { return fileName; } /** * @return the rowCount */ public int getRowCount() { return rowCount; } /** * @return the headerRow */ public List<String> getHeaderRow() { return headerRow; } /** * @return the dataRows */ public List<Map<String, CompositeVariant>> getDataRowsAsCompositeVariants() { return dataRows; } public Long getRowNum(Map<String, CompositeVariant> row) { if (row.containsKey(ROW_NUMBER)) { return (Long) row.get(ROW_NUMBER).getValueAs(Long.class); } else { return (long) dataRows.indexOf(row); } } /** * @return the requiredColumns */ public List<String> getRequiredColumns() { return requiredColumns; } public String convertHeaderName(String str) { String name; if (str.contains("@")) { name = StringUtils.substringBefore(str, "@"); } else { name = str; } if (enableHeaderNameConversion) { name = String.valueOf(name).toLowerCase().replaceAll("[^0-9a-zA-Z:\\-]+", "_"); } return name; } /** * Look for type hints in the name of a column to extract a usable type. * Also look for array hints as well. <br> * Possible formats: * <ul> * <li>column-name - A column named "column-name" </li> * <li>col@int - An integer column named "col" </li> * <li>col2@int[] - An integer array colum named "col2", assumes standard * delimiter (,) </li> * <li>col3@string[] or col3@[] - A String array named "col3", assumes * standard delimiter (,)</li> * <li>col4@string[||] - A string array where values are using a custom * delimiter (||)</li> * </ul> * * @param name * @return */ private Class detectTypeFromName(String name) { boolean isArray = false; Class detectedClass = String.class; if (name.contains("@")) { String typeStr = StringUtils.substringAfter(name, "@"); if (name.endsWith("]")) { String colName = convertHeaderName(name); isArray = true; String delimiter = StringUtils.substringBetween(name, "[", "]"); typeStr = StringUtils.substringBefore("[", delimiter); if (!StringUtils.isEmpty(delimiter)) { delimiters.put(colName, delimiter); } } detectedClass = getClassFromName(typeStr); } if (isArray) { return getArrayType(detectedClass); } else { return detectedClass; } } private Class getClassFromName(String typeStr) { switch (typeStr.toLowerCase()) { case "int": case "integer": return Integer.TYPE; case "long": return Long.TYPE; case "double": case "number": return Double.TYPE; case "date": case "calendar": case "cal": case "time": return Date.class; case "boolean": case "bool": return Boolean.TYPE; case "string": case "str": default: return String.class; } } /** * Consider if a column is seen twice then that column type should be * considered an array. Because String is a default assumption when no type * is specified, any redefinition of a column to a more specific type will * be then assumed for that property altogether. * * @param a * @param b * @return */ private Class upgradeToArray(Class a, Class b) { if (a == null) { return b; } if (b == null) { return a; } if (a.equals(b) || b == String.class) { return getArrayType(a); } else { return getArrayType(b); } } private static Class getArrayType(Class clazz) { if (clazz.isArray()) { return clazz; } else { return Array.newInstance(clazz, 0).getClass(); } } }