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
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:)
其他回答
// VersionComparator.java
import java.util.Comparator;
public class VersionComparator implements Comparator {
public boolean equals(Object o1, Object o2) {
return compare(o1, o2) == 0;
}
public int compare(Object o1, Object o2) {
String version1 = (String) o1;
String version2 = (String) o2;
VersionTokenizer tokenizer1 = new VersionTokenizer(version1);
VersionTokenizer tokenizer2 = new VersionTokenizer(version2);
int number1 = 0, number2 = 0;
String suffix1 = "", suffix2 = "";
while (tokenizer1.MoveNext()) {
if (!tokenizer2.MoveNext()) {
do {
number1 = tokenizer1.getNumber();
suffix1 = tokenizer1.getSuffix();
if (number1 != 0 || suffix1.length() != 0) {
// Version one is longer than number two, and non-zero
return 1;
}
}
while (tokenizer1.MoveNext());
// Version one is longer than version two, but zero
return 0;
}
number1 = tokenizer1.getNumber();
suffix1 = tokenizer1.getSuffix();
number2 = tokenizer2.getNumber();
suffix2 = tokenizer2.getSuffix();
if (number1 < number2) {
// Number one is less than number two
return -1;
}
if (number1 > number2) {
// Number one is greater than number two
return 1;
}
boolean empty1 = suffix1.length() == 0;
boolean empty2 = suffix2.length() == 0;
if (empty1 && empty2) continue; // No suffixes
if (empty1) return 1; // First suffix is empty (1.2 > 1.2b)
if (empty2) return -1; // Second suffix is empty (1.2a < 1.2)
// Lexical comparison of suffixes
int result = suffix1.compareTo(suffix2);
if (result != 0) return result;
}
if (tokenizer2.MoveNext()) {
do {
number2 = tokenizer2.getNumber();
suffix2 = tokenizer2.getSuffix();
if (number2 != 0 || suffix2.length() != 0) {
// Version one is longer than version two, and non-zero
return -1;
}
}
while (tokenizer2.MoveNext());
// Version two is longer than version one, but zero
return 0;
}
return 0;
}
}
// VersionTokenizer.java
public class VersionTokenizer {
private final String _versionString;
private final int _length;
private int _position;
private int _number;
private String _suffix;
private boolean _hasValue;
public int getNumber() {
return _number;
}
public String getSuffix() {
return _suffix;
}
public boolean hasValue() {
return _hasValue;
}
public VersionTokenizer(String versionString) {
if (versionString == null)
throw new IllegalArgumentException("versionString is null");
_versionString = versionString;
_length = versionString.length();
}
public boolean MoveNext() {
_number = 0;
_suffix = "";
_hasValue = false;
// No more characters
if (_position >= _length)
return false;
_hasValue = true;
while (_position < _length) {
char c = _versionString.charAt(_position);
if (c < '0' || c > '9') break;
_number = _number * 10 + (c - '0');
_position++;
}
int suffixStart = _position;
while (_position < _length) {
char c = _versionString.charAt(_position);
if (c == '.') break;
_position++;
}
_suffix = _versionString.substring(suffixStart, _position);
if (_position < _length) _position++;
return true;
}
}
例子:
public class Main
{
private static VersionComparator cmp;
public static void main (String[] args)
{
cmp = new VersionComparator();
Test(new String[]{"1.1.2", "1.2", "1.2.0", "1.2.1", "1.12"});
Test(new String[]{"1.3", "1.3a", "1.3b", "1.3-SNAPSHOT"});
}
private static void Test(String[] versions) {
for (int i = 0; i < versions.length; i++) {
for (int j = i; j < versions.length; j++) {
Test(versions[i], versions[j]);
}
}
}
private static void Test(String v1, String v2) {
int result = cmp.compare(v1, v2);
String op = "==";
if (result < 0) op = "<";
if (result > 0) op = ">";
System.out.printf("%s %s %s\n", v1, op, v2);
}
}
输出:
1.1.2 == 1.1.2 ---> same length and value
1.1.2 < 1.2 ---> first number (1) less than second number (2) => -1
1.1.2 < 1.2.0 ---> first number (1) less than second number (2) => -1
1.1.2 < 1.2.1 ---> first number (1) less than second number (2) => -1
1.1.2 < 1.12 ---> first number (1) less than second number (12) => -1
1.2 == 1.2 ---> same length and value
1.2 == 1.2.0 ---> first shorter than second, but zero
1.2 < 1.2.1 ---> first shorter than second, and non-zero
1.2 < 1.12 ---> first number (2) less than second number (12) => -1
1.2.0 == 1.2.0 ---> same length and value
1.2.0 < 1.2.1 ---> first number (0) less than second number (1) => -1
1.2.0 < 1.12 ---> first number (2) less than second number (12) => -1
1.2.1 == 1.2.1 ---> same length and value
1.2.1 < 1.12 ---> first number (2) less than second number (12) => -1
1.12 == 1.12 ---> same length and value
1.3 == 1.3 ---> same length and value
1.3 > 1.3a ---> first suffix ('') is empty, but not second ('a') => 1
1.3 > 1.3b ---> first suffix ('') is empty, but not second ('b') => 1
1.3 > 1.3-SNAPSHOT ---> first suffix ('') is empty, but not second ('-SNAPSHOT') => 1
1.3a == 1.3a ---> same length and value
1.3a < 1.3b ---> first suffix ('a') compared to second suffix ('b') => -1
1.3a < 1.3-SNAPSHOT ---> first suffix ('a') compared to second suffix ('-SNAPSHOT') => -1
1.3b == 1.3b ---> same length and value
1.3b < 1.3-SNAPSHOT ---> first suffix ('b') compared to second suffix ('-SNAPSHOT') => -1
1.3-SNAPSHOT == 1.3-SNAPSHOT ---> same length and value
使用Maven真的很简单:
import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
DefaultArtifactVersion minVersion = new DefaultArtifactVersion("1.0.1");
DefaultArtifactVersion maxVersion = new DefaultArtifactVersion("1.10");
DefaultArtifactVersion version = new DefaultArtifactVersion("1.11");
if (version.compareTo(minVersion) < 0 || version.compareTo(maxVersion) > 0) {
System.out.println("Sorry, your version is unsupported");
}
您可以从这个页面获得Maven Artifact的正确依赖项字符串:
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-artifact</artifactId>
<version>3.0.3</version>
</dependency>
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。
我写了一个小的Java/Android库来比较版本号:https://github.com/G00fY2/version-compare
它的基本功能是:
public int compareVersions(String versionA, String versionB) {
String[] versionTokensA = versionA.split("\\.");
String[] versionTokensB = versionB.split("\\.");
List<Integer> versionNumbersA = new ArrayList<>();
List<Integer> versionNumbersB = new ArrayList<>();
for (String versionToken : versionTokensA) {
versionNumbersA.add(Integer.parseInt(versionToken));
}
for (String versionToken : versionTokensB) {
versionNumbersB.add(Integer.parseInt(versionToken));
}
final int versionASize = versionNumbersA.size();
final int versionBSize = versionNumbersB.size();
int maxSize = Math.max(versionASize, versionBSize);
for (int i = 0; i < maxSize; i++) {
if ((i < versionASize ? versionNumbersA.get(i) : 0) > (i < versionBSize ? versionNumbersB.get(i) : 0)) {
return 1;
} else if ((i < versionASize ? versionNumbersA.get(i) : 0) < (i < versionBSize ? versionNumbersB.get(i) : 0)) {
return -1;
}
}
return 0;
}
这个代码片段不提供任何错误检查或处理。除此之外，我的库还支持像“1.2-rc”>“1.2-beta”这样的后缀。
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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