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
使用Java 9自带的Version类
import java.util.*;
import java.lang.module.ModuleDescriptor.Version;
class Main {
public static void main(String[] args) {
var versions = Arrays.asList(
"1.0.2",
"1.0.0-beta.2",
"1.0.0",
"1.0.0-beta",
"1.0.0-alpha.12",
"1.0.0-beta.11",
"1.0.1",
"1.0.11",
"1.0.0-rc.1",
"1.0.0-alpha.1",
"1.1.0",
"1.0.0-alpha.beta",
"1.11.0",
"1.0.0-alpha.12.ab-c",
"0.0.1",
"1.2.1",
"1.0.0-alpha",
"1.0.0.1", // Also works with a number of sections different than 3
"1.0.0.2",
"2",
"10",
"1.0.0.10"
);
versions.stream()
.map(Version::parse)
.sorted()
.forEach(System.out::println);
}
}
在网上试试!
输出:
0.0.1
1.0.0-alpha
1.0.0-alpha.1
1.0.0-alpha.12
1.0.0-alpha.12.ab-c
1.0.0-alpha.beta
1.0.0-beta
1.0.0-beta.2
1.0.0-beta.11
1.0.0-rc.1
1.0.0
1.0.0.1
1.0.0.2
1.0.0.10
1.0.1
1.0.2
1.0.11
1.1.0
1.2.1
1.11.0
2
10
其他回答
用点作为分隔符对字符串进行标记，然后从左边开始并排比较整数转换。
也许有人会对我的解决方案感兴趣:
class Version private constructor(private val versionString: String) : Comparable<Version> {
private val major: Int by lazy { versionString.split(".")[0].toInt() }
private val minor: Int by lazy { versionString.split(".")[1].toInt() }
private val patch: Int by lazy {
val splitArray = versionString.split(".")
if (splitArray.size == 3)
splitArray[2].toInt()
else
0
}
override fun compareTo(other: Version): Int {
return when {
major > other.major -> 1
major < other.major -> -1
minor > other.minor -> 1
minor < other.minor -> -1
patch > other.patch -> 1
patch < other.patch -> -1
else -> 0
}
}
override fun equals(other: Any?): Boolean {
if (other == null || other !is Version) return false
return compareTo(other) == 0
}
override fun hashCode(): Int {
return major * minor * patch
}
companion object {
private fun doesContainsVersion(string: String): Boolean {
val versionArray = string.split(".")
return versionArray.size in 2..3
&& versionArray[0].toIntOrNull() != null
&& versionArray[1].toIntOrNull() != null
&& (versionArray.size == 2 || versionArray[2].toIntOrNull() != null)
}
fun from(string: String): Version? {
return if (doesContainsVersion(string)) {
Version(string)
} else {
null
}
}
}
}
用法:
val version1 = Version.from("3.2")
val version2 = Version.from("3.2.1")
version1 <= version2
基于https://stackoverflow.com/a/27891752/2642478
class Version(private val value: String) : Comparable<Version> {
private val splitted by lazy { value.split("-").first().split(".").map { it.toIntOrNull() ?: 0 } }
override fun compareTo(other: Version): Int {
for (i in 0 until maxOf(splitted.size, other.splitted.size)) {
val compare = splitted.getOrElse(i) { 0 }.compareTo(other.splitted.getOrElse(i) { 0 })
if (compare != 0)
return compare
}
return 0
}
}
你可以用like:
System.err.println(Version("1.0").compareTo( Version("1.0")))
System.err.println(Version("1.0") < Version("1.1"))
System.err.println(Version("1.10") > Version("1.9"))
System.err.println(Version("1.10.1") > Version("1.10"))
System.err.println(Version("0.0.1") < Version("1"))
public class VersionComparator {
/* loop through both version strings
* then loop through the inner string to computer the val of the int
* for each integer read, do num*10+<integer read>
* and stop when stumbling upon '.'
* When '.' is encountered...
* see if '.' is encountered for both strings
* if it is then compare num1 and num2
* if num1 == num2... iterate over p1++, p2++
* else return (num1 > num2) ? 1 : -1
* If both the string end then compare(num1, num2) return 0, 1, -1
* else loop through the longer string and
* verify if it only has trailing zeros
* If it only has trailing zeros then return 0
* else it is greater than the other string
*/
public static int compareVersions(String v1, String v2) {
int num1 = 0;
int num2 = 0;
int p1 = 0;
int p2 = 0;
while (p1 < v1.length() && p2 < v2.length()) {
num1 = Integer.parseInt(v1.charAt(p1) + "");
num2 = Integer.parseInt(v2.charAt(p2) + "");
p1++;
p2++;
while (p1 < v1.length() && p2 < v2.length() && v1.charAt(p1) != '.' && v2.charAt(p2) != '.') {
if (p1 < v1.length()) num1 = num1 * 10 + Integer.parseInt(v1.charAt(p1) + "");
if (p2 < v2.length()) num2 = num2 * 10 + Integer.parseInt(v2.charAt(p2) + "");
p1++;
p2++;
}
if (p1 < v1.length() && p2 < v2.length() && v1.charAt(p1) == '.' && v2.charAt(p2) == '.') {
if ((num1 ^ num2) == 0) {
p1++;
p2++;
}
else return (num1 > num2) ? 1 : -1;
}
else if (p1 < v1.length() && p2 < v2.length() && v1.charAt(p1) == '.') return -1;
else if (p1 < v1.length() && p2 < v2.length() && v2.charAt(p2) == '.') return 1;
}
if (p1 == v1.length() && p2 == v2.length()) {
if ((num1 ^ num2) == 0) return 0;
else return (num1 > num2) ? 1 : -1;
}
else if (p1 == v1.length()) {
if ((num1 ^ num2) == 0) {
while (p2 < v2.length()) {
if (v2.charAt(p2) != '.' && v2.charAt(p2) != '0') return -1;
p2++;
}
return 0;
}
else return (num1 > num2) ? 1 : -1;
}
else {
if ((num1 ^ num2) == 0) {
while (p1 < v1.length()) {
if (v1.charAt(p1) != '.' && v1.charAt(p1) != '0') return 1;
p1++;
}
return 0;
}
else return (num1 > num2) ? 1 : -1;
}
}
public static void main(String[] args) {
System.out.println(compareVersions("11.23", "11.21.1.0.0.1.0") ^ 1);
System.out.println(compareVersions("11.21.1.0.0.1.0", "11.23") ^ -1);
System.out.println(compareVersions("11.23", "11.23.0.0.0.1.0") ^ -1);
System.out.println(compareVersions("11.2", "11.23") ^ -1);
System.out.println(compareVersions("11.23", "11.21.1.0.0.1.0") ^ 1);
System.out.println(compareVersions("1.21.1.0.0.1.0", "2.23") ^ -1);
System.out.println(compareVersions("11.23", "11.21.1.0.0.1.0") ^ 1);
System.out.println(compareVersions("11.23.0.0.0.0.0", "11.23") ^ 0);
System.out.println(compareVersions("11.23", "11.21.1.0.0.1.0") ^ 1);
System.out.println(compareVersions("1.5.1.3", "1.5.1.3.0") ^ 0);
System.out.println(compareVersions("1.5.1.4", "1.5.1.3.0") ^ 1);
System.out.println(compareVersions("1.2.1.3", "1.5.1.3.0") ^ -1);
System.out.println(compareVersions("1.2.1.3", "1.22.1.3.0") ^ -1);
System.out.println(compareVersions("1.222.1.3", "1.22.1.3.0") ^ 1);
}
}
我现在就做了，然后问自己，这对吗?因为我从来没有找到过比我的更干净的解决方案
你只需要像下面这样拆分字符串版本("1.0.0"):
userVersion.split("\\.")
那么你将得到:{"1"，"0"，"0"}
现在，用我做过的方法
isUpdateAvailable(userVersion.split("\\."), latestVersionSplit.split("\\."));
方法:
/**
* Compare two versions
*
* @param userVersionSplit - User string array with major, minor and patch version from user (exemple: {"5", "2", "70"})
* @param latestVersionSplit - Latest string array with major, minor and patch version from api (example: {"5", "2", "71"})
* @return true if user version is smaller than latest version
*/
public static boolean isUpdateAvailable(String[] userVersionSplit, String[] latestVersionSplit) {
try {
int majorUserVersion = Integer.parseInt(userVersionSplit[0]);
int minorUserVersion = Integer.parseInt(userVersionSplit[1]);
int patchUserVersion = Integer.parseInt(userVersionSplit[2]);
int majorLatestVersion = Integer.parseInt(latestVersionSplit[0]);
int minorLatestVersion = Integer.parseInt(latestVersionSplit[1]);
int patchLatestVersion = Integer.parseInt(latestVersionSplit[2]);
if (majorUserVersion <= majorLatestVersion) {
if (majorUserVersion < majorLatestVersion) {
return true;
} else {
if (minorUserVersion <= minorLatestVersion) {
if (minorUserVersion < minorLatestVersion) {
return true;
} else {
return patchUserVersion < patchLatestVersion;
}
}
}
}
} catch (Exception ignored) {
// Will be throw only if the versions pattern is different from "x.x.x" format
// Will return false at the end
}
return false;
}
等待任何反馈:)
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