1 /*
2 * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.util.calendar;
27
28 import java.util.HashMap;
29 import java.util.Map;
30
31 public class CalendarUtils {
32
33 /**
34 * Returns whether the specified year is a leap year in the Gregorian
35 * calendar system.
36 *
37 * @param gregorianYear a Gregorian calendar year
38 * @return true if the given year is a leap year in the Gregorian
39 * calendar system.
40 * @see CalendarDate#isLeapYear
41 */
42 public static final boolean isGregorianLeapYear(int gregorianYear) {
43 return (((gregorianYear % 4) == 0)
44 && (((gregorianYear % 100) != 0) || ((gregorianYear % 400) == 0)));
45 }
46
47 /**
48 * Returns whether the specified year is a leap year in the Julian
49 * calendar system. The year number must be a normalized one
50 * (e.g., 45 B.C.E. is 1-45).
51 *
52 * @param normalizedJulianYear a normalized Julian calendar year
53 * @return true if the given year is a leap year in the Julian
54 * calendar system.
55 * @see CalendarDate#isLeapYear
56 */
57 public static final boolean isJulianLeapYear(int normalizedJulianYear) {
58 return (normalizedJulianYear % 4) == 0;
59 }
60
61 /**
62 * Divides two integers and returns the floor of the quotient.
63 * For example, <code>floorDivide(-1, 4)</code> returns -1 while
64 * -1/4 is 0.
65 *
66 * @param n the numerator
67 * @param d a divisor that must be greater than 0
68 * @return the floor of the quotient
69 */
70 public static final long floorDivide(long n, long d) {
71 return ((n >= 0) ?
72 (n / d) : (((n + 1L) / d) - 1L));
73 }
74
75 /**
76 * Divides two integers and returns the floor of the quotient.
77 * For example, <code>floorDivide(-1, 4)</code> returns -1 while
78 * -1/4 is 0.
79 *
80 * @param n the numerator
81 * @param d a divisor that must be greater than 0
82 * @return the floor of the quotient
83 */
84 public static final int floorDivide(int n, int d) {
85 return ((n >= 0) ?
86 (n / d) : (((n + 1) / d) - 1));
87 }
88
89 /**
90 * Divides two integers and returns the floor of the quotient and
91 * the modulus remainder. For example,
92 * <code>floorDivide(-1,4)</code> returns <code>-1</code> with
93 * <code>3</code> as its remainder, while <code>-1/4</code> is
94 * <code>0</code> and <code>-1%4</code> is <code>-1</code>.
95 *
96 * @param n the numerator
97 * @param d a divisor which must be > 0
98 * @param r an array of at least one element in which the value
99 * <code>mod(n, d)</code> is returned.
100 * @return the floor of the quotient.
101 */
102 public static final int floorDivide(int n, int d, int[] r) {
103 if (n >= 0) {
104 r[0] = n % d;
105 return n / d;
106 }
107 int q = ((n + 1) / d) - 1;
108 r[0] = n - (q * d);
109 return q;
110 }
111
112 /**
113 * Divides two integers and returns the floor of the quotient and
114 * the modulus remainder. For example,
115 * <code>floorDivide(-1,4)</code> returns <code>-1</code> with
116 * <code>3</code> as its remainder, while <code>-1/4</code> is
117 * <code>0</code> and <code>-1%4</code> is <code>-1</code>.
118 *
119 * @param n the numerator
120 * @param d a divisor which must be > 0
121 * @param r an array of at least one element in which the value
122 * <code>mod(n, d)</code> is returned.
123 * @return the floor of the quotient.
124 */
125 public static final int floorDivide(long n, int d, int[] r) {
126 if (n >= 0) {
127 r[0] = (int)(n % d);
128 return (int)(n / d);
129 }
130 int q = (int)(((n + 1) / d) - 1);
131 r[0] = (int)(n - (q * d));
132 return q;
133 }
134
135 public static final long mod(long x, long y) {
136 return (x - y * floorDivide(x, y));
137 }
138
139 public static final int mod(int x, int y) {
140 return (x - y * floorDivide(x, y));
141 }
142
143 public static final int amod(int x, int y) {
144 int z = mod(x, y);
145 return (z == 0) ? y : z;
146 }
147
148 public static final long amod(long x, long y) {
149 long z = mod(x, y);
150 return (z == 0) ? y : z;
151 }
152
153 /**
154 * Mimics sprintf(buf, "%0*d", decaimal, width).
155 */
156 public static final StringBuilder sprintf0d(StringBuilder sb, int value, int width) {
157 long d = value;
158 if (d < 0) {
159 sb.append('-');
160 d = -d;
161 --width;
162 }
163 int n = 10;
164 for (int i = 2; i < width; i++) {
165 n *= 10;
166 }
167 for (int i = 1; i < width && d < n; i++) {
168 sb.append('0');
169 n /= 10;
170 }
171 sb.append(d);
172 return sb;
173 }
174
175 public static final StringBuffer sprintf0d(StringBuffer sb, int value, int width) {
176 long d = value;
177 if (d < 0) {
178 sb.append('-');
179 d = -d;
180 --width;
181 }
182 int n = 10;
183 for (int i = 2; i < width; i++) {
184 n *= 10;
185 }
186 for (int i = 1; i < width && d < n; i++) {
187 sb.append('0');
188 n /= 10;
189 }
190 sb.append(d);
191 return sb;
192 }
193 }