Requires commons-lang3-3.8.1.jar for string operations.
/**
* Compares two version strings.
*
* Use this instead of String.compareTo() for a non-lexicographical
* comparison that works for version strings. e.g. "1.10".compareTo("1.6").
*
* @param v1 a string of alpha numerals separated by decimal points.
* @param v2 a string of alpha numerals separated by decimal points.
* @return The result is 1 if v1 is greater than v2.
* The result is 2 if v2 is greater than v1.
* The result is -1 if the version format is unrecognized.
* The result is zero if the strings are equal.
*/
public int VersionCompare(String v1,String v2)
{
int v1Len=StringUtils.countMatches(v1,".");
int v2Len=StringUtils.countMatches(v2,".");
if(v1Len!=v2Len)
{
int count=Math.abs(v1Len-v2Len);
if(v1Len>v2Len)
for(int i=1;i<=count;i++)
v2+=".0";
else
for(int i=1;i<=count;i++)
v1+=".0";
}
if(v1.equals(v2))
return 0;
String[] v1Str=StringUtils.split(v1, ".");
String[] v2Str=StringUtils.split(v2, ".");
for(int i=0;i<v1Str.length;i++)
{
String str1="",str2="";
for (char c : v1Str[i].toCharArray()) {
if(Character.isLetter(c))
{
int u=c-'a'+1;
if(u<10)
str1+=String.valueOf("0"+u);
else
str1+=String.valueOf(u);
}
else
str1+=String.valueOf(c);
}
for (char c : v2Str[i].toCharArray()) {
if(Character.isLetter(c))
{
int u=c-'a'+1;
if(u<10)
str2+=String.valueOf("0"+u);
else
str2+=String.valueOf(u);
}
else
str2+=String.valueOf(c);
}
v1Str[i]="1"+str1;
v2Str[i]="1"+str2;
int num1=Integer.parseInt(v1Str[i]);
int num2=Integer.parseInt(v2Str[i]);
if(num1!=num2)
{
if(num1>num2)
return 1;
else
return 2;
}
}
return -1;
}