java实现的版本号比较

1/**
2 *  实现版本号比较
3 * 支持任意数字字母版本号比较，这里实现的是用点号（.）作为分隔符
4 * 支持任意长度的小版本号比较
5 */
6public static int compareVersion(String ver1, String ver2){
7		if(ver1 == null && ver2 == null){
8			throw new RuntimeException("版本号不能都为空");
9		}
10		
11		if(ver1 == null){
12			return -1;
13		}
14		
15		if(ver2 == null){
16			return 1;
17		}
18		
19		if(ver1.equals(ver2)) {
20			return 0;
21		}
22
23		String [] version1 = ver1.split("\\.");
24		String [] version2 = ver2.split("\\.");
25		
26			
27		String defValue = "0000000000";
28		String format = "%" + defValue.length() + "s";
29		StringBuilder ver1Builder = new StringBuilder(version1.length * 10);
30		StringBuilder ver2Builder = new StringBuilder(version2.length * 10);
31		
32		if(version1.length > version2.length) {
33			for (int i=0; i<version1.length ;i++ ) {
34				ver1Builder.append(String.format(format, version1[i]).replace(' ', '0'));
35				ver2Builder.append(version2.length > i? String.format(format, version2[i]).replace(' ', '0') : defValue);
36			}
37		
38		} else if(version1.length < version2.length){
39			for (int i=0; i<version2.length ;i++ ) {
40				ver2Builder.append(String.format(format, version2[i]).replace(' ', '0'));
41				ver1Builder.append(version1.length > i? String.format(format, version1[i]).replace(' ', '0') : defValue);
42			}
43
44		} else {
45			for (int i=0; i<version2.length ;i++ ) {
46				ver1Builder.append(String.format(format, version1[i]).replace(' ', '0'));
47				ver2Builder.append(String.format(format, version2[i]).replace(' ', '0'));
48			}
49		}
50
51		return ver1Builder.toString().compareTo(ver2Builder.toString());
52	}
53

测试代码

1compareVersion("1.2", "1.2.312.3") //返回<0的数字    
2
3compareVersion("12", "1.2.M1") //返回>0的数字
4
5compareVersion("1.2.3M", "1.2.3M") //返回0