|
1
5 package org.h2.util;
6
7 import java.io.ByteArrayInputStream  ;
8 import java.io.ByteArrayOutputStream ;
9 import java.io.ObjectInputStream ;
10 import java.io.ObjectOutputStream ;
11 import java.sql.SQLException ;
12
13 import org.h2.message.Message;
14
15
16 public class ByteUtils {
17
18 private static final char[] HEX = "0123456789abcdef".toCharArray();
19
20 public static int readInt(byte[] buff, int pos) {
21 return (buff[pos++]<< 24) + ((buff[pos++] & 0xff) << 16)
22 + ((buff[pos++] & 0xff) << 8) + (buff[pos++] & 0xff);
23 }
24
25 public static long readLong(byte[] buff, int pos) {
26 return ((long)(readInt(buff, pos)) << 32) + (readInt(buff, pos+4) & 0xffffffffL);
27 }
28
29 public static int indexOf(byte[] bytes, byte[] pattern, int start) {
30 if (pattern.length == 0) {
31 return start;
32 }
33 if (start > bytes.length) {
34 return -1;
35 }
36 int last = bytes.length - pattern.length + 1;
37 next:
38 for(;start < last; start++) {
39 for(int i=0; i<pattern.length; i++) {
40 if(bytes[start + i] != pattern[i]) {
41 continue next;
42 }
43 }
44 return start;
45 }
46 return -1;
47 }
48
49 public static byte[] convertStringToBytes(String s) throws SQLException {
50 int len = s.length();
51 if (len % 2 != 0) {
52 throw Message.getSQLException(Message.HEX_STRING_ODD_1, s);
53 }
54 len /= 2;
55 byte[] buff = new byte[len];
56 try {
57 for (int i = 0; i < len; i++) {
58 buff[i] = (byte) ((Character.digit(s.charAt(i+i), 16) << 4) | (Character.digit(s.charAt(i+i+1), 16)));
59 }
60 } catch (NumberFormatException e) {
61 throw Message.getSQLException(Message.HEX_STRING_WRONG_1, s);
62 }
63 return buff;
64 }
65
66 public static int getByteArrayHash(byte[] value) {
67 int h = 1;
68 for (int i = 0; i < value.length;) {
69 h = 31 * h + value[i++];
70 }
71 return h;
72 }
73
74 public static String convertBytesToString(byte[] value) {
75 return convertBytesToString(value, value.length);
76 }
77
78 public static String convertBytesToString(byte[] value, int len) {
79 char[] buff = new char[len+len];
80 char[] hex = HEX;
81 for (int i = 0; i < len; i++) {
82 int c = value[i] & 0xff;
83 buff[i+i] = hex[c >> 4];
84 buff[i+i+1] = hex[c & 0xf];
85 }
86 return new String (buff);
87 }
88
89 public static boolean compareSecure(byte[] test, byte[] good) {
90 if((test==null) || (good==null)) {
91 return (test == null) && (good == null);
92 }
93 if(test.length != good.length) {
94 return false;
95 }
96 if(test.length == 0) {
97 return true;
98 }
99 boolean correct = true, correct2 = false;
101 for(int i=0; i<good.length; i++) {
102 if(test[i] != good[i]) {
103 correct = false;
104 } else {
105 correct2 = true;
106 }
107 }
108 return correct && correct2;
109 }
110
111 public static void clear(byte[] buff) {
112 for(int i=0; i<buff.length; i++) {
113 buff[i] = 0;
114 }
115 }
116
117 public static int compareNotNull(byte[] data1, byte[] data2) {
118 int len = Math.min(data1.length, data2.length);
119 for (int i = 0; i < len; i++) {
120 byte b = data1[i];
121 byte b2 = data2[i];
122 if (b != b2) {
123 return b > b2 ? 1 : -1;
124 }
125 }
126 int c = data1.length - data2.length;
127 return c == 0 ? 0 : (c < 0 ? -1 : 1);
128 }
129
130 public static String convertToBinString(byte[] buff) {
131 char[] chars = new char[buff.length];
132 for(int i=0; i<buff.length; i++) {
133 chars[i] = (char) (buff[i] & 0xff);
134 }
135 return new String (chars);
136 }
137
138 public static byte[] convertBinStringToBytes(String data) {
139 byte[] buff = new byte[data.length()];
140 for(int i=0; i<data.length(); i++) {
141 buff[i] = (byte) (data.charAt(i) & 0xff);
142 }
143 return buff;
144 }
145
146 public static byte[] copy(byte[] source, byte[] target) {
147 int len = source.length;
148 if(len > target.length) {
149 target = new byte[len];
150 }
151 System.arraycopy(source, 0, target, 0, len);
152 return target;
153 }
154
155 public static byte[] cloneByteArray(byte[] b) {
156 int len = b.length;
157 if(len == 0) {
158 return b;
159 }
160 byte[] copy = new byte[len];
161 System.arraycopy(b, 0, copy, 0, len);
162 return copy;
163 }
164
165 public static byte[] serialize(Object obj) throws SQLException {
166 try {
167 ByteArrayOutputStream out = new ByteArrayOutputStream ();
168 ObjectOutputStream os = new ObjectOutputStream (out);
169 os.writeObject(obj);
170 return out.toByteArray();
171 } catch(Throwable e) {
172 throw Message.getSQLException(Message.SERIALIZATION_FAILED, null, e);
173 }
174 }
175
176 public static Object deserialize(byte[] data) throws SQLException {
177 try {
178 ByteArrayInputStream in = new ByteArrayInputStream (data);
179 ObjectInputStream is = new ObjectInputStream (in);
180 Object obj = is.readObject();
181 return obj;
182 } catch(Throwable e) {
183 throw Message.getSQLException(Message.DESERIALIZATION_FAILED, null, e);
184 }
185 }
186
187 }
188 |
Popular Tags |
Java API By Example, From Geeks To Geeks.