java byte 循环左移循环右移 rotateLeft rotateRight

java byte 循环左移循环右移 rotateLeft rotateRight

1.概念。

　　循环左移：

　　　　eg1：byte in = (byte) 0x01;【0000 0001】则循环左移2位后变为【0000 0100】

　　　　eg2: btye in = (byte)0x90;[1001 0000],则循环左移2位变为[0100 0010]

　　循环右移：

　　　　eg3：byte in = (byte)0x01;[0000 0001]则循环右移2位后变为[0100 0000]

　　　　eg4：byte in = (byte)0x90;[1001 0000]则循环右移2位后变为[0010 0100]

2.示例。

 1 public class DataConvertUtil {
 2     /**
 3      * 循环左移
 4      * @param sourceByte 待左移动的值
 5      * @param n 左移动的为数
 6      * @return
 7      */
 8     public static byte rotateLeft(byte sourceByte, int n) {
 9         // 去除高位的1
10         int temp = sourceByte & 0xFF;
11         return (byte) ((temp << n) | (temp >>> (8 - n)));
12     }
13     /**
14      * 循环右移
15      * @param sourceByte
16      * @param n
17      * @return
18      */
19     public static byte rotateRight(byte sourceByte, int n) {
20         // 去除高位的1
21         int temp = sourceByte & 0xFF;
22         return (byte) ((temp >>> n) | (temp << (8 - n)));
23     }
24     /**
25      * 循环左移
26      * @param sourceBytes
27      * @param n
28      * @return
29      */
30     public static byte[] rotateLeft(byte[] sourceBytes, int n) {
31         byte[] out = new byte[sourceBytes.length];
32         for (int i = 0; i < sourceBytes.length; i++) {
33             out[i] = rotateLeft(sourceBytes[i], n);
34         }
35         return out;
36     }
37     
38     public static byte[] rotateRight(byte[] sourceBytes, int n) {
39         byte[] out = new byte[sourceBytes.length];
40         for (int i = 0; i < sourceBytes.length; i++) {
41             out[i] = rotateRight(sourceBytes[i], n);
42         }
43         return out;
44     }
45 }

3.一个简单的测试类

 1 import static org.junit.Assert.*;
 2 
 3 import org.junit.Test;
 4 
 5 public class DataConvertUtilTest {
 6 
 7     @Test
 8     public void test() {
 9         System.out.println("originByte" 
10                 + "|" + "BinaryOrig"
11                 + "|" + "outByte"
12                 + "|" + "BinaryOut"
13                 + "|" + "outLength");
14         byte[] sourceBytes = new byte[]{(byte)(0x01),(byte)(0x03),5,(byte)(0x07),(byte)(0x0f)
15                 ,(byte)(0x1f),(byte)(0x3F),(byte)(0x7F),(byte)(0xFF),(byte)(0xF0),(byte)(0xC0)
16                 };
17         byte[] out = DataConvertUtil.rotateRight(sourceBytes, 2);
18         for (int i = 0; i < out.length; i++) {
19             System.out.println("rright"
20                     + "|" + sourceBytes[i] 
21                     + "|" + Integer.toBinaryString(sourceBytes[i])
22                     + "|" + Byte.toString(out[i])
23                     + "|" + Integer.toBinaryString(out[i])
24                     + "|" + Integer.toBinaryString(out[i]).length()
25                     + "|" + Integer.toBinaryString(out[i]).indexOf('0'));
26         }
27         System.out.println();
28         out = DataConvertUtil.rotateLeft(sourceBytes, 2);
29         for (int i = 0; i < out.length; i++) {
30             System.out.println("rleft"
31                     + "|" + sourceBytes[i] 
32                     + "|" + Integer.toBinaryString(sourceBytes[i])
33                     + "|" + Byte.toString(out[i])
34                     + "|" + Integer.toBinaryString(out[i])
35                     + "|" + Integer.toBinaryString(out[i]).length()
36                     + "|" + Integer.toBinaryString(out[i]).indexOf('0'));
37         }
38     }
39 
40 }

java byte 循环左移 循环右移 rotateLeft rotateRight

java byte 循环左移循环右移 rotateLeft rotateRight