Java tutorial
/*************************************************************************** Copyright (c) 2016, EPAM SYSTEMS INC 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.epam.dlab.core.parser; import com.epam.dlab.exceptions.ParseException; import com.epam.dlab.model.aws.ReportLine; import org.apache.commons.lang3.StringUtils; import java.text.DecimalFormat; import java.text.DecimalFormatSymbols; import java.util.ArrayList; import java.util.LinkedHashMap; import java.util.List; /** * Provides common format features. */ public class CommonFormat { /** * Character for separate field names and values. */ public static final char FIELD_SEPARATOR = ','; /** * Character for termination field names and values. */ public static final char FIELD_DELIMITER = '"'; /** * Escape character. */ public static final char ESCAPE_CHAR = '\\'; /** * Default character used for decimal sign. */ public static final char DECIMAL_SEPARATOR_DEFAULT = '.'; /** * Default character used for thousands separator. */ public static final char DECIMAL_GROUPING_SEPARATOR_DEFAULT = ' '; /** * String of the field separator for replacement to target data. */ private static final String DELIMITER_REPLACE_FROM = String.valueOf(FIELD_DELIMITER); /** * String of the escaped field separator for replacement to target data. */ private static final String DELIMITER_REPLACE_TO = new StringBuilder().append(ESCAPE_CHAR) .append(FIELD_DELIMITER).toString(); /** * Formatter for convert decimal numbers to string. */ private static final DecimalFormat DECIMAL_TO_STRING_FORMAT; static { DECIMAL_TO_STRING_FORMAT = new DecimalFormat(); DecimalFormatSymbols symbols = new DecimalFormatSymbols(); symbols.setDecimalSeparator(DECIMAL_SEPARATOR_DEFAULT); DECIMAL_TO_STRING_FORMAT.setDecimalFormatSymbols(symbols); DECIMAL_TO_STRING_FORMAT.setGroupingUsed(false); DECIMAL_TO_STRING_FORMAT.setMaximumFractionDigits(100); } /** * Column meta information. */ private final ColumnMeta columnMeta; /** * Formatter for parse of decimal number . */ private final DecimalFormat sourceDecimalFormat; /** * Instantiate the helper for common format. * * @param columnMeta column meta information. */ public CommonFormat(ColumnMeta columnMeta) { this(columnMeta, DECIMAL_SEPARATOR_DEFAULT, DECIMAL_GROUPING_SEPARATOR_DEFAULT); } /** * Instantiate the helper for common format. * * @param columnMeta column meta information. * @param decimalSeparator the character used for decimal sign. * @param groupingSeparator the character used for thousands separator. */ public CommonFormat(ColumnMeta columnMeta, char sourceDecimalSeparator, char sourceGroupingSeparator) { this.columnMeta = columnMeta; this.sourceDecimalFormat = getDecimalFormat(sourceDecimalSeparator, sourceGroupingSeparator); } /** * Create and return the target row for common format from source. * * @param sourceRow the source row. * @return row in common format. * @throws ParseException */ public ReportLine toCommonFormat(List<String> sourceRow) throws ParseException { if (columnMeta.getColumnMapping() == null) { return toReportLine(sourceRow); } List<String> targetRow = new ArrayList<String>(); for (ColumnInfo columnInfo : columnMeta.getColumnMapping()) { targetRow.add((columnInfo.sourceIndex < 0 ? "" : (columnInfo.sourceIndex < sourceRow.size() ? sourceRow.get(columnInfo.sourceIndex) : null))); } return toReportLine(targetRow); } /** * Add the column value to string in CSV format. * * @param sb the buffer of sting. * @param value the value. * @return the buffer of string. */ private static StringBuilder addToStringBuilder(StringBuilder sb, String value) { if (sb.length() > 0) { sb.append(FIELD_SEPARATOR); } return sb.append(FIELD_DELIMITER) .append(StringUtils.replace(value, DELIMITER_REPLACE_FROM, DELIMITER_REPLACE_TO)) .append(FIELD_DELIMITER); } /** * Convert row to line in CSV format. * * @param row row for convertation. * @return string in CSV format. */ public static String rowToString(List<String> row) { StringBuilder sb = new StringBuilder(); for (String s : row) { addToStringBuilder(sb, s); } return sb.toString(); } /** * Convert row to line in CSV format. * * @param row row for convertation. * @return string in CSV format. */ public static String rowToString(ReportLine row) { StringBuilder sb = new StringBuilder(); addToStringBuilder(sb, row.getDlabId()); addToStringBuilder(sb, row.getUser()); addToStringBuilder(sb, row.getUsageDate()); addToStringBuilder(sb, row.getProduct()); addToStringBuilder(sb, row.getUsageType()); addToStringBuilder(sb, doubleToString(row.getUsage())); addToStringBuilder(sb, doubleToString(row.getCost())); addToStringBuilder(sb, row.getCurrencyCode()); addToStringBuilder(sb, row.getResourceType().toString()); addToStringBuilder(sb, row.getResourceId()); if (row.getTags() != null) { for (String key : row.getTags().keySet()) { addToStringBuilder(sb, row.getTags().get(key)); } } return sb.toString(); } /** * Create and return decimal formatter. * * @param decimalSeparator the character used for decimal sign. * @param groupingSeparator the character used for thousands separator. * @return Formatter for decimal digits. */ private DecimalFormat getDecimalFormat(char decimalSeparator, char groupingSeparator) { DecimalFormat df = new DecimalFormat(); DecimalFormatSymbols symbols = new DecimalFormatSymbols(); symbols.setDecimalSeparator(decimalSeparator); symbols.setGroupingSeparator(groupingSeparator); df.setDecimalFormatSymbols(symbols); return df; } /** * Parse and return double value. If value is <b>null</b> or empty return zero. * * @param columnName the name of column. * @param value the value. * @throws ParseException */ public double parseDouble(String columnName, String value) throws ParseException { if (value == null || value.trim().isEmpty()) { return 0; } try { return sourceDecimalFormat.parse(value).doubleValue(); } catch (Exception e) { throw new ParseException("Cannot cast column " + columnName + " value \"" + value + "\" to double: " + e.getLocalizedMessage(), e); } } /** * Return the string representation of double value. * * @param value the value. */ public static String doubleToString(double value) { return DECIMAL_TO_STRING_FORMAT.format(value); } /** * Creates and returns the line of billing report from the list of values. * * @param row the list of values. * @return the line of billing report. * @throws ParseException */ public ReportLine toReportLine(List<String> row) throws ParseException { if (row.size() < ColumnMeta.TAG_COLUMN_INDEX || row.size() > columnMeta.getTargetColumnNames().size()) { throw new ParseException( "Invalid the number of columns in list: expected from " + ColumnMeta.TAG_COLUMN_INDEX + " to " + columnMeta.getTargetColumnNames().size() + ", actual " + row.size()); } ReportLine line = new ReportLine(); int i = 0; line.setDlabId(row.get(i)); line.setUser(row.get(++i)); line.setUsageDate(row.get(++i)); line.setProduct(row.get(++i)); line.setUsageType(row.get(++i)); line.setUsage(parseDouble("usage", row.get(++i))); line.setCost(parseDouble("cost", row.get(++i))); line.setCurrencyCode(row.get(++i)); line.setResourceTypeId(row.get(++i)); if (row.size() >= ColumnMeta.TAG_COLUMN_INDEX) { LinkedHashMap<String, String> tags = new LinkedHashMap<>(); i++; while (i < row.size()) { tags.put(columnMeta.getTargetColumnNames().get(i), row.get(i++)); } line.setTags(tags); } return line; } /** * Print row to console. * * @param row array of values. */ public static void printRow(String[] row) { System.out.print(" | "); for (String s : row) { System.out.print(s + " | "); } System.out.println(); } /** * Print row to console. * * @param row list of values. */ public static void printRow(List<String> row) { printRow(row.toArray(new String[row.size()])); } }