JAVA 软件升级版本号比较

简单版本号比较：

public class CompareVersion {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

java.lang.System.out.println

( value( "10.1.2.0" ) > value( "9.0.0.0" ));  

}

 

public static long value(final java.lang.String string) {

if (string.contains(".")) {

final int index = string.lastIndexOf(".");

return value(string.substring(0, index)) * 100

+ value(string.substring(index + 1));

} else

return java.lang.Long.valueOf(string);

}

}

上边的简单版本号递归算法并不算好

下面我们看一个复杂点，但非常实用的版本号比较类:

public class Scratch
{
    private static class VersionStringComparator
            implements Comparator<String>
    {
        public int compare(String s1, String s2){
            if( s1 == null && s2 == null )
                return 0;
            else if( s1 == null )
                return -1;
            else if( s2 == null )
                return 1;

String[]
                arr1 = s1.split("[^a-zA-Z0-9]+"),
                arr2 = s2.split("[^a-zA-Z0-9]+")
            ;

int i1, i2, i3;

for(int ii = 0, max = Math.min(arr1.length, arr2.length); 
ii <= max; ii++){
                if( ii == arr1.length )
                    return ii == arr2.length ? 0 : -1;
                else if( ii == arr2.length )
                    return 1;

try{
                    i1 = Integer.parseInt(arr1[ii]);
                }
                catch (Exception x){
                    i1 = Integer.MAX_VALUE;
                }

try{
                    i2 = Integer.parseInt(arr2[ii]);
                }
                catch (Exception x){
                    i2 = Integer.MAX_VALUE;
                }

if( i1 != i2 ){
                    return i1 - i2;
                }

i3 = arr1[ii].compareTo(arr2[ii]);

if( i3 != 0 )
                    return i3;
            }

return 0;
        }
    }

public static void main(String[] ss){

String[] data = new String[]{
            "2.0",
            "1.5.1",
            "10.1.2.0",
            "9.0.0.0",
            "2.0.0.16",
            "1.6.0_07",
            "1.6.0_07-b06",
            "1.6.0_6",
            "1.6.0_07-b07",
            "1.6.0_08-a06",
            "5.10",
            "Generic_127127-11",
            "Generic_127127-13"
        };

List<String> list = Arrays.asList(data);
        Collections.sort(list, new VersionStringComparator());

for(String s: list)
            System.out.println(s);
    }
}
</code>

<output>
  1.5.1
  1.6.0_6
  1.6.0_07
  1.6.0_07-b06
  1.6.0_07-b07
  1.6.0_08-a06
  2.0
  2.0.0.16
  5.10
  9.0.0.0
  10.1.2.0
  Generic_127127-11
  Generic_127127-13
</output>

如果简单的比较版本号，抽取其中的compare（）方法即可！

欢迎转载！