是否有比较版本号的标准习语?我不能直接使用String compareTo,因为我还不知道点释放的最大数量是多少。我需要比较版本,并有以下保持正确:
1.0 < 1.1
1.0.1 < 1.1
1.9 < 1.10
是否有比较版本号的标准习语?我不能直接使用String compareTo,因为我还不知道点释放的最大数量是多少。我需要比较版本,并有以下保持正确:
1.0 < 1.1
1.0.1 < 1.1
1.9 < 1.10
当前回答
科特林:
@kotlin.jvm.Throws(InvalidParameterException::class)
fun String.versionCompare(remoteVersion: String?): Int {
val remote = remoteVersion?.splitToSequence(".")?.toList() ?: return 1
val local = this.splitToSequence(".").toList()
if(local.filter { it.toIntOrNull() != null }.size != local.size) throw InvalidParameterException("version invalid: $this")
if(remote.filter { it.toIntOrNull() != null }.size != remote.size) throw InvalidParameterException("version invalid: $remoteVersion")
val totalRange = 0 until kotlin.math.max(local.size, remote.size)
for (i in totalRange) {
if (i < remote.size && i < local.size) {
val result = local[i].compareTo(remote[i])
if (result != 0) return result
} else (
return local.size.compareTo(remote.size)
)
}
return 0
}
其他回答
由于本页上没有答案能很好地处理混合文本,我做了自己的版本:
import java.util.regex.Matcher;
import java.util.regex.Pattern;
class Main {
static double parseVersion(String v) {
if (v.isEmpty()) {
return 0;
}
Pattern p = Pattern.compile("^(\\D*)(\\d*)(\\D*)$");
Matcher m = p.matcher(v);
m.find();
if (m.group(2).isEmpty()) {
// v1.0.0.[preview]
return -1;
}
double i = Integer.parseInt(m.group(2));
if (!m.group(3).isEmpty()) {
// v1.0.[0b]
i -= 0.1;
}
return i;
}
public static int versionCompare(String str1, String str2) {
String[] v1 = str1.split("\\.");
String[] v2 = str2.split("\\.");
int i = 0;
for (; i < v1.length && i < v2.length; i++) {
double iv1 = parseVersion(v1[i]);
double iv2 = parseVersion(v2[i]);
if (iv1 != iv2) {
return iv1 - iv2 < 0 ? -1 : 1;
}
}
if (i < v1.length) {
// "1.0.1", "1.0"
double iv1 = parseVersion(v1[i]);
return iv1 < 0 ? -1 : (int) Math.ceil(iv1);
}
if (i < v2.length) {
double iv2 = parseVersion(v2[i]);
return -iv2 < 0 ? -1 : (int) Math.ceil(iv2);
}
return 0;
}
public static void main(String[] args) {
System.out.println("versionCompare(v1.0.0, 1.0.0)");
System.out.println(versionCompare("v1.0.0", "1.0.0")); // 0
System.out.println("versionCompare(v1.0.0b, 1.0.0)");
System.out.println(versionCompare("v1.0.0b", "1.0.0")); // -1
System.out.println("versionCompare(v1.0.0.preview, 1.0.0)");
System.out.println(versionCompare("v1.0.0.preview", "1.0.0")); // -1
System.out.println("versionCompare(v1.0, 1.0.0)");
System.out.println(versionCompare("v1.0", "1.0.0")); // 0
System.out.println("versionCompare(ver1.0, 1.0.1)");
System.out.println(versionCompare("ver1.0", "1.0.1")); // -1
}
}
不过,在需要比较“alpha”和“beta”的情况下,它仍然不够。
我喜欢@Peter Lawrey的想法,我把它扩展到更远的范围:
/**
* Normalize string array,
* Appends zeros if string from the array
* has length smaller than the maxLen.
**/
private String normalize(String[] split, int maxLen){
StringBuilder sb = new StringBuilder("");
for(String s : split) {
for(int i = 0; i<maxLen-s.length(); i++) sb.append('0');
sb.append(s);
}
return sb.toString();
}
/**
* Removes trailing zeros of the form '.00.0...00'
* (and does not remove zeros from, say, '4.1.100')
**/
public String removeTrailingZeros(String s){
int i = s.length()-1;
int k = s.length()-1;
while(i >= 0 && (s.charAt(i) == '.' || s.charAt(i) == '0')){
if(s.charAt(i) == '.') k = i-1;
i--;
}
return s.substring(0,k+1);
}
/**
* Compares two versions(works for alphabets too),
* Returns 1 if v1 > v2, returns 0 if v1 == v2,
* and returns -1 if v1 < v2.
**/
public int compareVersion(String v1, String v2) {
// Uncomment below two lines if for you, say, 4.1.0 is equal to 4.1
// v1 = removeTrailingZeros(v1);
// v2 = removeTrailingZeros(v2);
String[] splitv1 = v1.split("\\.");
String[] splitv2 = v2.split("\\.");
int maxLen = 0;
for(String str : splitv1) maxLen = Math.max(maxLen, str.length());
for(String str : splitv2) maxLen = Math.max(maxLen, str.length());
int cmp = normalize(splitv1, maxLen).compareTo(normalize(splitv2, maxLen));
return cmp > 0 ? 1 : (cmp < 0 ? -1 : 0);
}
希望它能帮助到别人。它通过了interviewbit和leetcode中的所有测试用例(需要取消compareVersion函数中的两行注释)。
很容易测试!
public int compare(String v1, String v2) {
v1 = v1.replaceAll("\\s", "");
v2 = v2.replaceAll("\\s", "");
String[] a1 = v1.split("\\.");
String[] a2 = v2.split("\\.");
List<String> l1 = Arrays.asList(a1);
List<String> l2 = Arrays.asList(a2);
int i=0;
while(true){
Double d1 = null;
Double d2 = null;
try{
d1 = Double.parseDouble(l1.get(i));
}catch(IndexOutOfBoundsException e){
}
try{
d2 = Double.parseDouble(l2.get(i));
}catch(IndexOutOfBoundsException e){
}
if (d1 != null && d2 != null) {
if (d1.doubleValue() > d2.doubleValue()) {
return 1;
} else if (d1.doubleValue() < d2.doubleValue()) {
return -1;
}
} else if (d2 == null && d1 != null) {
if (d1.doubleValue() > 0) {
return 1;
}
} else if (d1 == null && d2 != null) {
if (d2.doubleValue() > 0) {
return -1;
}
} else {
break;
}
i++;
}
return 0;
}
我创建了一个简单的实用程序,使用语义版本约定在Android平台上比较版本。所以它只适用于X.Y.Z (Major.Minor.Patch)格式的字符串,其中X、Y和Z是非负整数。你可以在我的GitHub上找到它。
方法version . compareversions (String v1, String v2)比较两个版本字符串。如果版本相等则返回0,如果版本v1在版本v2之前则返回1,如果版本v1在版本v2之后则返回-1,如果版本格式无效则返回-2。
您需要规范化版本字符串,以便对它们进行比较。类似的
import java.util.regex.Pattern;
public class Main {
public static void main(String... args) {
compare("1.0", "1.1");
compare("1.0.1", "1.1");
compare("1.9", "1.10");
compare("1.a", "1.9");
}
private static void compare(String v1, String v2) {
String s1 = normalisedVersion(v1);
String s2 = normalisedVersion(v2);
int cmp = s1.compareTo(s2);
String cmpStr = cmp < 0 ? "<" : cmp > 0 ? ">" : "==";
System.out.printf("'%s' %s '%s'%n", v1, cmpStr, v2);
}
public static String normalisedVersion(String version) {
return normalisedVersion(version, ".", 4);
}
public static String normalisedVersion(String version, String sep, int maxWidth) {
String[] split = Pattern.compile(sep, Pattern.LITERAL).split(version);
StringBuilder sb = new StringBuilder();
for (String s : split) {
sb.append(String.format("%" + maxWidth + 's', s));
}
return sb.toString();
}
}
打印
'1.0' < '1.1' '1.0.1' < '1.1' '1.9' < '1.10' “1。A ' > '1.9'