在socket开发过程中，通常需要将一些具体的值（这些值可能是各种JAVA类型）转化为byte[]类型，为此我总结了如下这个示例，贴出来，以便经常翻看
Java代码
![byte[]与各种数据类型互相转换示例_System](https://file.cfanz.cn/uploads/gif/2022/01/16/14/XV476I6FI5.gif "复制代码")
1. public class TestCase {
2.
3.
4. public static byte[] shortToByte(short number) {
5. int temp = number;
6. byte[] b = new byte[2];
7. for (int i = 0; i < b.length; i++) {
8. b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位
9. temp = temp >> 8;// 向右移8位
10. }
11. return b;
12. }
13.
14.
15. public static short byteToShort(byte[] b) {
16. short s = 0;
17. short s0 = (short) (b[0] & 0xff);// 最低位
18. short s1 = (short) (b[1] & 0xff);
19. s1 <<= 8;
20. s = (short) (s0 | s1);
21. return s;
22. }
23.
24.
25.
26. public static byte[] intToByte(int number) {
27. int temp = number;
28. byte[] b = new byte[4];
29. for (int i = 0; i < b.length; i++) {
30. b[i] = new Integer(temp & 0xff).byteValue();// 将最低位保存在最低位
31. temp = temp >> 8;// 向右移8位
32. }
33. return b;
34. }
35.
36.
37. public static int byteToInt(byte[] b) {
38. int s = 0;
39. int s0 = b[0] & 0xff;// 最低位
40. int s1 = b[1] & 0xff;
41. int s2 = b[2] & 0xff;
42. int s3 = b[3] & 0xff;
43. s3 <<= 24;
44. s2 <<= 16;
45. s1 <<= 8;
46. s = s0 | s1 | s2 | s3;
47. return s;
48. }
49.
50.
51.
52. public static byte[] longToByte(long number) {
53. long temp = number;
54. byte[] b = new byte[8];
55. for (int i = 0; i < b.length; i++) {
56. b[i] = new Long(temp & 0xff).byteValue();// 将最低位保存在最低位 temp = temp
57. // >> 8;// 向右移8位
58. }
59. return b;
60. }
61.
62.
63. public static long byteToLong(byte[] b) {
64. long s = 0;
65. long s0 = b[0] & 0xff;// 最低位
66. long s1 = b[1] & 0xff;
67. long s2 = b[2] & 0xff;
68. long s3 = b[3] & 0xff;
69. long s4 = b[4] & 0xff;// 最低位
70. long s5 = b[5] & 0xff;
71. long s6 = b[6] & 0xff;
72. long s7 = b[7] & 0xff;
73.
74. // s0不变
75. s1 <<= 8;
76. s2 <<= 16;
77. s3 <<= 24;
78. s4 <<= 8 * 4;
79. s5 <<= 8 * 5;
80. s6 <<= 8 * 6;
81. s7 <<= 8 * 7;
82. s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;
83. return s;
84. }
85.
86.
87. public static byte[] doubleToByte(double num) {
88. byte[] b = new byte[8];
89. long l = Double.doubleToLongBits(num);
90. for (int i = 0; i < 8; i++) {
91. b[i] = new Long(l).byteValue();
92. l = l >> 8;
93. }
94. return b;
95. }
96.
97.
98. public static double getDouble(byte[] b) {
99. long m;
100. m = b[0];
101. m &= 0xff;
102. m |= ((long) b[1] << 8);
103. m &= 0xffff;
104. m |= ((long) b[2] << 16);
105. m &= 0xffffff;
106. m |= ((long) b[3] << 24);
107. m &= 0xffffffffl;
108. m |= ((long) b[4] << 32);
109. m &= 0xffffffffffl;
110. m |= ((long) b[5] << 40);
111. m &= 0xffffffffffffl;
112. m |= ((long) b[6] << 48);
113. m &= 0xffffffffffffffl;
114. m |= ((long) b[7] << 56);
115. return Double.longBitsToDouble(m);
116. }
117.
118.
119.
120. public static void floatToByte(float x) {
121. //先用 Float.floatToIntBits(f)转换成int
122. }
123.
124.
125. public static float getFloat(byte[] b) {
126. // 4 bytes
127. int accum = 0;
128. for ( int shiftBy = 0; shiftBy < 4; shiftBy++ ) {
129. accum |= (b[shiftBy] & 0xff) << shiftBy * 8;
130. }
131. return Float.intBitsToFloat(accum);
132. }
133.
134.
135. public static byte[] charToByte(char c){
136. byte[] b = new byte[2];
137. b[0] = (byte) ((c & 0xFF00) >> 8);
138. b[1] = (byte) (c & 0xFF);
139. return b;
140. }
141.
142.
143. public static char byteToChar(byte[] b){
144. char c = (char) (((b[0] & 0xFF) << 8) | (b[1] & 0xFF));
145. return c;
146. }
147.
148.
149. public static byte[] stringToByte(String str) throws UnsupportedEncodingException{
150. return str.getBytes("GBK");
151. }
152.
153.
154. public static String bytesToString(byte[] str) {
155. String keyword = null;
156. try {
157. keyword = new String(str,"GBK");
158. } catch (UnsupportedEncodingException e) {
159. e.printStackTrace();
160. }
161. return keyword;
162. }
163.
164.
165.
166. @Test
167. public void testObject2ByteArray() throws IOException,
168. ClassNotFoundException {
169. // Object obj = "";
170. Integer[] obj = { 1, 3, 4 };
171.
172. // // object to bytearray
173. ByteArrayOutputStream bo = new ByteArrayOutputStream();
174. ObjectOutputStream oo = new ObjectOutputStream(bo);
175. oo.writeObject(obj);
176. byte[] bytes = bo.toByteArray();
177. bo.close();
178. oo.close();
179. System.out.println(Arrays.toString(bytes));
180.
181. Integer[] intArr = (Integer[]) testByteArray2Object(bytes);
182. System.out.println(Arrays.asList(intArr));
183.
184.
185. byte[] b2 = intToByte(123);
186. System.out.println(Arrays.toString(b2));
187.
188. int a = byteToInt(b2);
189. System.out.println(a);
190.
191. }
192.
193.
194. private Object testByteArray2Object(byte[] bytes) throws IOException,
195. ClassNotFoundException {
196. // byte[] bytes = null;
197. Object obj;
198. // bytearray to object
199. ByteArrayInputStream bi = new ByteArrayInputStream(bytes);
200. ObjectInputStream oi = new ObjectInputStream(bi);
201. obj = oi.readObject();
202. bi.close();
203. oi.close();
204. System.out.println(obj);
205. return obj;
206. }
207.
208. }Java代码
