1 package org.djunits.unit;
2
3 import org.djunits.unit.si.SIDimensions;
4 import org.djunits.unit.util.UnitException;
5
6 /**
7 * SIUnit describes a unit with arbitrary SI dimensions for which no predefined unit exists.
8 * <p>
9 * Copyright (c) 2019-2023 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
10 * BSD-style license. See <a href="https://djunits.org/docs/license.html">DJUNITS License</a>
11 * </p>
12 * @author <a href="https://www.tudelft.nl/averbraeck" target="_blank">Alexander Verbraeck</a>
13 */
14 public class SIUnit extends Unit<SIUnit>
15 {
16 /** */
17 private static final long serialVersionUID = 20190829L;
18
19 static
20 {
21 // make sure all predefined unit types get registered before we start using SIScalars.
22 try
23 {
24 Class.forName("org.djunits.unit.util.UNITS");
25 }
26 catch (ClassNotFoundException exception)
27 {
28 exception.printStackTrace();
29 }
30 }
31
32 /**
33 * Instantiate an SI unit 'of' a String.
34 * @param siString String; the SI string, e.g., "kgm/s2"
35 * @return the SIUnit based on the SI dimensionality
36 * @throws UnitException when the SI string is not according to the rules
37 */
38 public static SIUnit of(final String siString) throws UnitException
39 {
40 return Unit.lookupOrCreateUnitWithSIDimensions(SIDimensions.of(siString));
41 }
42
43 /**
44 * Instantiate an SI unit 'of' a SIDimensions.
45 * @param siDimensions SIDimensions; the SI dimensions
46 * @return the SIUnit based on the SI dimensionality
47 * @throws UnitException when the SI string is not according to the rules
48 */
49 public static SIUnit of(final SIDimensions siDimensions) throws UnitException
50 {
51 return Unit.lookupOrCreateUnitWithSIDimensions(siDimensions);
52 }
53
54 /** {@inheritDoc} */
55 @Override
56 public String toString()
57 {
58 return getQuantity().getSiDimensions().toString(true, false);
59 }
60
61 /** {@inheritDoc} */
62 @Override
63 @SuppressWarnings("checkstyle:designforextension")
64 public int hashCode()
65 {
66 return getQuantity().getSiDimensions().hashCode();
67 }
68
69 /** {@inheritDoc} */
70 @Override
71 @SuppressWarnings({"checkstyle:designforextension", "checkstyle:needbraces"})
72 public boolean equals(final Object obj)
73 {
74 if (this == obj)
75 return true;
76 if (obj == null)
77 return false;
78 if (getClass() != obj.getClass())
79 return false;
80 SIUnit other = (SIUnit) obj;
81 if (!getQuantity().getSiDimensions().equals(other.getQuantity().getSiDimensions()))
82 return false;
83 return true;
84 }
85
86 }