| 1 | /* |
| 2 | * JScience - Java(TM) Tools and Libraries for the Advancement of Sciences. |
| 3 | * Copyright (C) 2007 - JScience (http://jscience.org/) |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Permission to use, copy, modify, and distribute this software is |
| 7 | * freely granted, provided that this notice is preserved. |
| 8 | */ |
| 9 | package javax.measure; |
| 10 | |
| 11 | import java.math.BigDecimal; |
| 12 | import java.text.FieldPosition; |
| 13 | import java.text.Format; |
| 14 | import java.text.NumberFormat; |
| 15 | import java.text.ParseException; |
| 16 | import java.text.ParsePosition; |
| 17 | |
| 18 | import javax.measure.unit.CompoundUnit; |
| 19 | import javax.measure.unit.Unit; |
| 20 | import javax.measure.unit.UnitFormat; |
| 21 | |
| 22 | /** |
| 23 | * <p> This class provides the interface for formatting and parsing {@link |
| 24 | * Measure measures}.</p> |
| 25 | * |
| 26 | * <p> As a minimum, instances of this class should be able to parse/format |
| 27 | * measure using {@link CompoundUnit}. </p> |
| 28 | * |
| 29 | * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a> |
| 30 | * @version 4.2, August 26, 2007 |
| 31 | */ |
| 32 | public abstract class MeasureFormat extends Format { |
| 33 | |
| 34 | /** |
| 35 | * Returns the measure format for the default locale. |
| 36 | * |
| 37 | * @return <code>getInstance(Number.getInstance(), Unit.getInstance())</code> |
| 38 | */ |
| 39 | public static MeasureFormat getInstance() { |
| 40 | return DEFAULT; |
| 41 | } |
| 42 | |
| 43 | static final NumberUnit DEFAULT = new NumberUnit(NumberFormat |
| 44 | .getInstance(), UnitFormat.getInstance()); |
| 45 | |
| 46 | /** |
| 47 | * Returns the measure format using the specified number format and |
| 48 | * unit format (the number and unit are separated by a space). |
| 49 | * |
| 50 | * @param numberFormat the number format. |
| 51 | * @param unitFormat the unit format. |
| 52 | * @return the corresponding format. |
| 53 | */ |
| 54 | public static MeasureFormat getInstance(NumberFormat numberFormat, |
| 55 | UnitFormat unitFormat) { |
| 56 | return new NumberUnit(numberFormat, unitFormat); |
| 57 | } |
| 58 | |
| 59 | // Holds default implementation. |
| 60 | static final class NumberUnit extends MeasureFormat { |
| 61 | private final NumberFormat _numberFormat; |
| 62 | |
| 63 | private final UnitFormat _unitFormat; |
| 64 | |
| 65 | private NumberUnit(NumberFormat numberFormat, UnitFormat unitFormat) { |
| 66 | _numberFormat = numberFormat; |
| 67 | _unitFormat = unitFormat; |
| 68 | } |
| 69 | |
| 70 | @Override |
| 71 | public StringBuffer format(Object obj, StringBuffer toAppendTo, |
| 72 | FieldPosition pos) { |
| 73 | Measure<?, ?> measure = (Measure<?, ?>) obj; |
| 74 | Object value = measure.getValue(); |
| 75 | Unit<?> unit = measure.getUnit(); |
| 76 | if (value instanceof Number) { |
| 77 | if (unit instanceof CompoundUnit) |
| 78 | return formatCompound(((Number) value).doubleValue(), |
| 79 | (CompoundUnit<?>) unit, toAppendTo, pos); |
| 80 | _numberFormat.format(value, toAppendTo, pos); |
| 81 | } else { |
| 82 | toAppendTo.append(value); |
| 83 | } |
| 84 | if (!measure.getUnit().equals(Unit.ONE)) { |
| 85 | toAppendTo.append(' '); |
| 86 | _unitFormat.format(unit, toAppendTo, pos); |
| 87 | } |
| 88 | return toAppendTo; |
| 89 | } |
| 90 | |
| 91 | // Measure using Compound unit have no separators in their representation. |
| 92 | StringBuffer formatCompound(double value, Unit<?> unit, |
| 93 | StringBuffer toAppendTo, FieldPosition pos) { |
| 94 | if (!(unit instanceof CompoundUnit)) { |
| 95 | toAppendTo.append((long) value); |
| 96 | return _unitFormat.format(unit, toAppendTo, pos); |
| 97 | } |
| 98 | Unit<?> high = ((CompoundUnit<?>) unit).getHigher(); |
| 99 | Unit<?> low = ((CompoundUnit<?>) unit).getLower(); // The unit in which the value is stated. |
| 100 | long highValue = (long) low.getConverterTo(high).convert(value); |
| 101 | double lowValue = value |
| 102 | - high.getConverterTo(low).convert(highValue); |
| 103 | formatCompound(highValue, high, toAppendTo, pos); |
| 104 | formatCompound(lowValue, low, toAppendTo, pos); |
| 105 | return toAppendTo; |
| 106 | } |
| 107 | |
| 108 | @Override |
| 109 | public Object parseObject(String source, ParsePosition pos) { |
| 110 | int start = pos.getIndex(); |
| 111 | try { |
| 112 | int i = start; |
| 113 | Number value = _numberFormat.parse(source, pos); |
| 114 | if (i == pos.getIndex()) |
| 115 | return null; // Cannot parse. |
| 116 | i = pos.getIndex(); |
| 117 | if (i >= source.length()) |
| 118 | return measureOf(value, Unit.ONE); // No unit. |
| 119 | boolean isCompound = !Character.isWhitespace(source.charAt(i)); |
| 120 | if (isCompound) |
| 121 | return parseCompound(value, source, pos); |
| 122 | if (++i >= source.length()) |
| 123 | return measureOf(value, Unit.ONE); // No unit. |
| 124 | pos.setIndex(i); // Skips separator. |
| 125 | Unit<?> unit = _unitFormat.parseProductUnit(source, pos); |
| 126 | return measureOf(value, unit); |
| 127 | } catch (ParseException e) { |
| 128 | pos.setIndex(start); |
| 129 | pos.setErrorIndex(e.getErrorOffset()); |
| 130 | return null; |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | @SuppressWarnings("unchecked") |
| 135 | private Object parseCompound(Number highValue, String source, |
| 136 | ParsePosition pos) throws ParseException { |
| 137 | Unit high = _unitFormat.parseSingleUnit(source, pos); |
| 138 | int i = pos.getIndex(); |
| 139 | if (i >= source.length() |
| 140 | || Character.isWhitespace(source.charAt(i))) |
| 141 | return measureOf(highValue, high); |
| 142 | Measure lowMeasure = (Measure) parseObject(source, pos); |
| 143 | Unit unit = lowMeasure.getUnit(); |
| 144 | long l = lowMeasure.longValue(unit) |
| 145 | + (long) high.getConverterTo(unit).convert( |
| 146 | highValue.longValue()); |
| 147 | return Measure.valueOf(l, unit); |
| 148 | } |
| 149 | |
| 150 | @SuppressWarnings("unchecked") |
| 151 | private static Measure measureOf(Number value, Unit unit) { |
| 152 | if (value instanceof Double) { |
| 153 | return Measure.valueOf(value.doubleValue(), unit); |
| 154 | } else if (value instanceof Long) { |
| 155 | return Measure.valueOf(value.longValue(), unit); |
| 156 | } else if (value instanceof Float) { |
| 157 | return Measure.valueOf(value.floatValue(), unit); |
| 158 | } else if (value instanceof Integer) { |
| 159 | return Measure.valueOf(value.intValue(), unit); |
| 160 | } else if (value instanceof BigDecimal) { |
| 161 | return DecimalMeasure.valueOf((BigDecimal) value, unit); |
| 162 | } else { |
| 163 | return Measure.valueOf(value.doubleValue(), unit); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | private static final long serialVersionUID = 1L; |
| 168 | } |
| 169 | } |