【问题标题】：How do you compare two version Strings in Java?你如何比较Java中的两个版本字符串？
【发布时间】：2010-09-16 22:33:26
【问题描述】：

有比较版本号的标准习语吗？我不能只使用直接的 String compareTo，因为我还不知道最大发布点数是多少。我需要比较版本并满足以下条件：

1.0 < 1.1
1.0.1 < 1.1
1.9 < 1.10

【问题讨论】：

您是否尝试仅删除点并将结果字符串解析为整数？我目前正在使用类似于以下内容的内容：String version = "1.1.2".replace(".", "");int number = Integer.parseInt(version); // = 112。您可以将该数字与另一个数字进行比较，从而找到更新的版本。此外，您可以检查version 字符串是否与\\d+\\.\\d+\\.\\d 等某些特定模式匹配，以使结果至少具有3 位数字。
@RegisteredUser 这将如何与以下内容一起使用：1.12.1 和 1.1.34 ？
您必须确保每个部分的长度相同。因此，要比较示例的两个版本，它们必须是这样的：1.12.01 和 1.01.34。在 java 中，您可以通过首先拆分 . 字符并比较每个元素的长度来实现这一点。之后只需将所有元素放入一个字符串中，然后将其解析为 int，然后将其与已以相同方式转换的另一个版本进行比较
只是想分享一下，这在 groovy stackoverflow.com/a/7737400/1195507 中实现的时间可能非常短@

标签： java comparison versioning

【解决方案1】：

这个旧帖子的另一个解决方案（对于那些可能有帮助的人）：

public class Version implements Comparable<Version> {

    private String version;

    public final String get() {
        return this.version;
    }

    public Version(String version) {
        if(version == null)
            throw new IllegalArgumentException("Version can not be null");
        if(!version.matches("[0-9]+(\\.[0-9]+)*"))
            throw new IllegalArgumentException("Invalid version format");
        this.version = version;
    }

    @Override public int compareTo(Version that) {
        if(that == null)
            return 1;
        String[] thisParts = this.get().split("\\.");
        String[] thatParts = that.get().split("\\.");
        int length = Math.max(thisParts.length, thatParts.length);
        for(int i = 0; i < length; i++) {
            int thisPart = i < thisParts.length ?
                Integer.parseInt(thisParts[i]) : 0;
            int thatPart = i < thatParts.length ?
                Integer.parseInt(thatParts[i]) : 0;
            if(thisPart < thatPart)
                return -1;
            if(thisPart > thatPart)
                return 1;
        }
        return 0;
    }

    @Override public boolean equals(Object that) {
        if(this == that)
            return true;
        if(that == null)
            return false;
        if(this.getClass() != that.getClass())
            return false;
        return this.compareTo((Version) that) == 0;
    }

}

Version a = new Version("1.1");
Version b = new Version("1.1.1");
a.compareTo(b) // return -1 (a<b)
a.equals(b)    // return false

Version a = new Version("2.0");
Version b = new Version("1.9.9");
a.compareTo(b) // return 1 (a>b)
a.equals(b)    // return false

Version a = new Version("1.0");
Version b = new Version("1");
a.compareTo(b) // return 0 (a=b)
a.equals(b)    // return true

Version a = new Version("1");
Version b = null;
a.compareTo(b) // return 1 (a>b)
a.equals(b)    // return false

List<Version> versions = new ArrayList<Version>();
versions.add(new Version("2"));
versions.add(new Version("1.0.5"));
versions.add(new Version("1.01.0"));
versions.add(new Version("1.00.1"));
Collections.min(versions).get() // return min version
Collections.max(versions).get() // return max version

// WARNING
Version a = new Version("2.06");
Version b = new Version("2.060");
a.equals(b)    // return false

编辑：

@daiscog：感谢您的评论，这段代码是为 Android 平台开发的，并且按照 Google 的建议，“匹配”方法检查整个字符串，这与使用规范模式的 Java 不同。 (Android documentation - JAVA documentation)

【讨论】：

这是最好的解决方案恕我直言。我通过将其更改为 if (!version.matches("[0-9]+(\\.[0-9]+){0,2}") 并添加一个变量将其限制为 3 个元素版本代码： private static final int[] PRIME = { 2, 3, 5 }; 我能够为上述创建缺少的 hashCode：@Override public final int hashCode() { final String[] parts = this.get().split ("\\."); int hashCode = 0; for (int i = 0; i 0) { hashCode += PRIME[i] ^ part; } } return hashCode; }
您至少应该缓存对Pattern.compile() 的隐式调用，因为您的逻辑是以O(N log N) 复杂性调用的。
这个实现覆盖了equals(Object that)，因此应该覆盖hashCode()。两个相等的对象必须返回相同的 hashCode 否则如果将这些对象与散列集合一起使用会遇到麻烦。
您不能对版本字符串进行哈希处理，因为 'new Version("1.0").equals(new Version("1")' 将返回 true。这将起作用，但效率低下.. . // 合约：任何两个相等的版本必须返回相同的 hashCode。 // 因为“1.0”等于“1”，所以我们不能返回版本字符串的 hashCode。@Override public int hashCode() { return 1 ; }
在 Kotlin 上转换 stackoverflow.com/a/61795721/6352712

【解决方案2】：

使用 Maven 真的很容易：

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this page 获取 Maven Artifact 的正确依赖字符串：

<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-artifact</artifactId>
<version>3.0.3</version>
</dependency>

【讨论】：

我已经创建了一个关于如何做到这一点的测试要点：gist.github.com/2627608
完美，不要重复造轮子！
只有一个担心是：使用这种包含大量文件的依赖项只是一个原因 - 拥有一个类 - DefaultArtifactVersion
@ses 存储很便宜 - 肯定比编写、测试和维护原始代码便宜
请注意，Comparable.compareTo 被记录为返回“负整数、零或正整数”，因此避免检查 -1 和 +1 是一个好习惯。

【解决方案3】：

用点作为分隔符对字符串进行标记，然后从左侧开始并排比较整数翻译。

【讨论】：

这是我怀疑我必须求助的。这还涉及在两个版本字符串中较短的一个中循环标记。感谢您的确认。
别忘了你可能并不总是只有数字。一些应用程序将包含内部版本号，并且可能包含 1.0.1b 等内容。
你是怎么做到的？
您编写了一个将字符串拆分为数字和非数字部分的正则表达式。在数字上比较数字部分和按字典顺序比较非数字部分。（也许也分点。）
它在“.1”和“1”的情况下不起作用。同样，可能还有其他用例

【解决方案4】：

您需要规范化版本字符串，以便可以比较它们。类似的东西

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'

【讨论】：

对规范化的警告是您在其中拥有的隐含最大宽度。
@IHeartAndroid 好点子，除非你期望 '4.1' == '4.1.0' 我认为这是一个有意义的排序。

【解决方案5】：

重用现有代码的最佳方式，取Maven's ComparableVersion class

优点：

Apache 许可证，2.0 版，
经过测试，
在 spring-security-core、jboss 等多个项目中使用（复制）
多个features
已经是 java.lang.Comparable
只需复制粘贴该类，没有第三方依赖项

不要包含对 maven-artifact 的依赖，因为这会拉取各种传递依赖

【讨论】：

这读起来像广告，并没有在其他答案中添加任何内容。
这与问题相关，因为它是关于比较版本和 Maven 版本比较的标准方法。
这是最好的答案。我不敢相信有多少其他人（包括被接受的）在没有测试的情况下尝试了一些 hacky 字符串拆分。使用此类的代码示例：assertTrue(new ComparableVersion("1.1-BETA").compareTo(new ComparableVersion("1.1-RC")) < 0)
缺点：引入大量依赖项，这意味着大量攻击面和版本冲突的可能性。
@toolforger，答案的最后一行建议不要将工件用作依赖项。相反，您可以只复制文件。就像在优势列表中所说的（两次）。

【解决方案6】：

// 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;
    }
}

示例：

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

【讨论】：

【解决方案7】：

想知道为什么每个人都认为版本仅由整数组成 - 在我的情况下不是。

为什么要重新发明轮子（假设版本遵循 Semver 标准）

首先通过 Maven 安装 https://github.com/vdurmont/semver4j

然后使用这个库

Semver sem = new Semver("1.2.3");
sem.isGreaterThan("1.2.2"); // true

【讨论】：

【解决方案8】：

使用 Java 9 的 own builtin `Version` class

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);
  }
}

Try it online!

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

【讨论】：

截至 2020 年，这应该是选定的答案。感谢发帖。

【解决方案9】：

public static int compareVersions(String version1, String version2){

    String[] levels1 = version1.split("\\.");
    String[] levels2 = version2.split("\\.");

    int length = Math.max(levels1.length, levels2.length);
    for (int i = 0; i < length; i++){
        Integer v1 = i < levels1.length ? Integer.parseInt(levels1[i]) : 0;
        Integer v2 = i < levels2.length ? Integer.parseInt(levels2[i]) : 0;
        int compare = v1.compareTo(v2);
        if (compare != 0){
            return compare;
        }
    }

    return 0;
}

【讨论】：

适用于简单的情况。
基于你的想法stackoverflow.com/a/62532745/2642478

【解决方案10】：

如果你的项目中已经有 Jackson，你可以使用com.fasterxml.jackson.core.Version:

import com.fasterxml.jackson.core.Version;
import org.junit.Test;

import static org.junit.Assert.assertTrue;

public class VersionTest {

    @Test
    public void shouldCompareVersion() {
        Version version1 = new Version(1, 11, 1, null, null, null);
        Version version2 = new Version(1, 12, 1, null, null, null);
        assertTrue(version1.compareTo(version2) < 0);
    }
}

【讨论】：

【解决方案11】：

@alex 在 Kotlin 上的 post

class Version(inputVersion: String) : Comparable<Version> {

        var version: String
            private set

        override fun compareTo(other: Version) =
            (split() to other.split()).let {(thisParts, thatParts)->
                val length = max(thisParts.size, thatParts.size)
                for (i in 0 until length) {
                    val thisPart = if (i < thisParts.size) thisParts[i].toInt() else 0
                    val thatPart = if (i < thatParts.size) thatParts[i].toInt() else 0
                    if (thisPart < thatPart) return -1
                    if (thisPart > thatPart) return 1
                }
                 0
            }

        init {
            require(inputVersion.matches("[0-9]+(\\.[0-9]+)*".toRegex())) { "Invalid version format" }
            version = inputVersion
        }
    }

    fun Version.split() = version.split(".").toTypedArray()

用法：

Version("1.2.4").compareTo(Version("0.0.5")) //return 1

【讨论】：

【解决方案12】：

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;
    }

【讨论】：

【解决方案13】：

/**  
 *  written by: Stan Towianski - May 2018 
 * notes: I make assumption each of 3 version sections a.b.c is not longer then 4 digits: aaaa.bbbb.cccc-MODWORD1(-)modnum2
 * 5.10.13-release-1 becomes 0000500100013.501     6.0-snapshot becomes 0000600000000.100
 * MODWORD1 = -xyz/NotMatching, -SNAPSHOT, -ALPHA, -BETA, -RC, -RELEASE/nothing  return:  .0, .1, .2, .3, .4, .5
 * modnum2 = up to 2 digit/chars second version
 * */
public class VersionCk {

    private static boolean isVersionHigher( String baseVersion, String testVersion )
        {
        System.out.println( "versionToComparable( baseVersion ) =" + versionToComparable( baseVersion ) );
        System.out.println( "versionToComparable( testVersion ) =" + versionToComparable( testVersion ) + " is this higher ?" );
        return versionToComparable( testVersion ).compareTo( versionToComparable( baseVersion ) ) > 0;
        }

    //----  not worrying about += for something so small
    private static String versionToComparable( String version )
        {
//        System.out.println("version - " + version);
        String versionNum = version;
        int at = version.indexOf( '-' );
        if ( at >= 0 )
            versionNum = version.substring( 0, at );

        String[] numAr = versionNum.split( "\\." );
        String versionFormatted = "0";
        for ( String tmp : numAr )
            {
            versionFormatted += String.format( "%4s", tmp ).replace(' ', '0');
            }
        while ( versionFormatted.length() < 12 )  // pad out to aaaa.bbbb.cccc
            {
            versionFormatted += "0000";
            }
//        System.out.println( "converted min version =" + versionFormatted + "=   : " + versionNum );
        return versionFormatted + getVersionModifier( version, at );
        }

    //----  use order low to high: -xyz, -SNAPSHOT, -ALPHA, -BETA, -RC, -RELEASE/nothing  returns: 0, 1, 2, 3, 4, 5
    private static String getVersionModifier( String version, int at )
        {
//        System.out.println("version - " + version );
        String[] wordModsAr = { "-SNAPSHOT", "-ALPHA", "-BETA", "-RC", "-RELEASE" };        

        if ( at < 0 )
            return "." + wordModsAr.length + "00";   // make nothing = RELEASE level

        int i = 1;
        for ( String word : wordModsAr )
            {
            if ( ( at = version.toUpperCase().indexOf( word ) ) > 0 )
                return "." + i + getSecondVersionModifier( version.substring( at + word.length() ) );
            i++;
            }

        return ".000";
        }

    //----  add 2 chars for any number after first modifier.  -rc2 or -rc-2   returns 02
    private static String getSecondVersionModifier( String version )
        {
        System.out.println( "second modifier =" + version + "=" );
        Matcher m = Pattern.compile("(.*?)(\\d+).*").matcher( version );
//        if ( m.matches() )
//            System.out.println( "match ? =" + m.matches() + "=   m.group(1) =" + m.group(1) + "=   m.group(2) =" + m.group(2) + "=   m.group(3) =" + (m.groupCount() >= 3 ? m.group(3) : "x") );
//        else
//            System.out.println( "No match" );
        return m.matches() ? String.format( "%2s", m.group(2) ).replace(' ', '0') : "00";
        }

    public static void main(String[] args) 
        {
        checkVersion( "3.10.0", "3.4.0");
        checkVersion( "5.4.2", "5.4.1");
        checkVersion( "5.4.4", "5.4.5");
        checkVersion( "5.4.9", "5.4.12");
        checkVersion( "5.9.222", "5.10.12");
        checkVersion( "5.10.12", "5.10.12");
        checkVersion( "5.10.13", "5.10.14");
        checkVersion( "6.7.0", "6.8");
        checkVersion( "6.7", "2.7.0");
        checkVersion( "6", "6.3.1");
        checkVersion( "4", "4.0.0");
        checkVersion( "6.3.0", "6");
        checkVersion( "5.10.12-Alpha", "5.10.12-beTA");
        checkVersion( "5.10.13-release", "5.10.14-beta");
        checkVersion( "6.7.0", "6.8-snapshot");
        checkVersion( "6.7.1", "6.7.0-release");
        checkVersion( "6-snapshot", "6.0.0-beta");
        checkVersion( "6.0-snapshot", "6.0.0-whatthe");
        checkVersion( "5.10.12-Alpha-1", "5.10.12-alpha-2");
        checkVersion( "5.10.13-release-1", "5.10.13-release2");
        checkVersion( "10-rc42", "10.0.0-rc53");
        }

    private static void checkVersion(String baseVersion, String testVersion) 
        {
        System.out.println( "baseVersion - " + baseVersion );
        System.out.println( "testVersion - " + testVersion );
        System.out.println( "isVersionHigher = " + isVersionHigher( baseVersion, testVersion ) );
        System.out.println( "---------------");
        }

    }

一些输出：

---------------
baseVersion - 6.7
testVersion - 2.7.0
versionToComparable( baseVersion ) =0000600070000.500
versionToComparable( testVersion ) =0000200070000.500 is this higher ?
isVersionHigher = false
---------------
baseVersion - 6
testVersion - 6.3.1
versionToComparable( baseVersion ) =0000600000000.500
versionToComparable( testVersion ) =0000600030001.500 is this higher ?
isVersionHigher = true
---------------
baseVersion - 4
testVersion - 4.0.0
versionToComparable( baseVersion ) =0000400000000.500
versionToComparable( testVersion ) =0000400000000.500 is this higher ?
isVersionHigher = false
---------------
baseVersion - 6.3.0
testVersion - 6
versionToComparable( baseVersion ) =0000600030000.500
versionToComparable( testVersion ) =0000600000000.500 is this higher ?
isVersionHigher = false
---------------
baseVersion - 5.10.12-Alpha
testVersion - 5.10.12-beTA
second modifier ==
versionToComparable( baseVersion ) =0000500100012.200
second modifier ==
versionToComparable( testVersion ) =0000500100012.300 is this higher ?
second modifier ==
second modifier ==
isVersionHigher = true
---------------
baseVersion - 5.10.13-release
testVersion - 5.10.14-beta
second modifier ==
versionToComparable( baseVersion ) =0000500100013.500
second modifier ==
versionToComparable( testVersion ) =0000500100014.300 is this higher ?
second modifier ==
second modifier ==
isVersionHigher = true
---------------
baseVersion - 6.7.0
testVersion - 6.8-snapshot
versionToComparable( baseVersion ) =0000600070000.500
second modifier ==
versionToComparable( testVersion ) =0000600080000.100 is this higher ?
second modifier ==
isVersionHigher = true
---------------
baseVersion - 6.7.1
testVersion - 6.7.0-release
versionToComparable( baseVersion ) =0000600070001.500
second modifier ==
versionToComparable( testVersion ) =0000600070000.500 is this higher ?
second modifier ==
isVersionHigher = false
---------------
baseVersion - 6-snapshot
testVersion - 6.0.0-beta
second modifier ==
versionToComparable( baseVersion ) =0000600000000.100
second modifier ==
versionToComparable( testVersion ) =0000600000000.300 is this higher ?
second modifier ==
second modifier ==
isVersionHigher = true
---------------
baseVersion - 6.0-snapshot
testVersion - 6.0.0-whatthe
second modifier ==
versionToComparable( baseVersion ) =0000600000000.100
versionToComparable( testVersion ) =0000600000000.000 is this higher ?
second modifier ==
isVersionHigher = false
---------------
baseVersion - 5.10.12-Alpha-1
testVersion - 5.10.12-alpha-2
second modifier =-1=
versionToComparable( baseVersion ) =0000500100012.201
second modifier =-2=
versionToComparable( testVersion ) =0000500100012.202 is this higher ?
second modifier =-2=
second modifier =-1=
isVersionHigher = true
---------------
baseVersion - 5.10.13-release-1
testVersion - 5.10.13-release2
second modifier =-1=
versionToComparable( baseVersion ) =0000500100013.501
second modifier =2=
versionToComparable( testVersion ) =0000500100013.502 is this higher ?
second modifier =2=
second modifier =-1=
isVersionHigher = true
---------------
baseVersion - 10-rc42
testVersion - 10.0.0-rc53
second modifier =42=
versionToComparable( baseVersion ) =0001000000000.442
second modifier =53=
versionToComparable( testVersion ) =0001000000000.453 is this higher ?
second modifier =53=
second modifier =42=
isVersionHigher = true
---------------

【讨论】：

【解决方案14】：

我编写了一个名为 MgntUtils 的开源库，它有一个适用于字符串版本的实用程序。它正确地比较它们，使用版本范围等等。这是这个库javadoc 请参阅方法TextUtils.comapreVersions(...)。它已被大量使用并经过良好测试。这是article，它描述了该库以及获取它的位置。它以Maven artifact 和github 的形式提供（带有源代码和JavaDoc）

【讨论】：

【解决方案15】：

我现在就这样做了，问自己，对吗？因为我之前从未找到比我最干净的解决方案：

你只需要像这个例子那样拆分字符串版本（“1.0.0”）：

userVersion.split("\\.")

那么你将有：{"1", "0", "0"}

现在，使用我所做的方法：

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:)

【讨论】：

干净简洁——我喜欢。
警告任何正在使用 kotlin 但想要得到这个答案的人，不要使用它。 Java String.split 的 in 参数是正则表达式，但 kotlin in 参数是字符串。这意味着对于 kotlin string.split(".") 就足够了。

【解决方案16】：

对于我的项目，我使用我的 commons-version 库 https://github.com/raydac/commons-version 它包含两个辅助类 - 解析版本（解析的版本可以与另一个版本对象进行比较，因为它是可比较的）和版本验证器，它允许检查某些表达式的版本，如!=ide-1.1.1,>idea-1.3.4-SNAPSHOT;<1.2.3

【讨论】：

【解决方案17】：

我使用Semantic Versioning 约定在Android 平台 上创建了简单的utility for comparing versions。因此它仅适用于 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。如果版本相等返回0，如果版本v1在版本v2之前返回1，如果版本v1在版本v2之后返回-1，如果版本格式无效返回-2。

【讨论】：

找不到你的 GitHub 链接

【解决方案18】：

public int CompareVersions(String version1, String version2)
{
    String[] string1Vals = version1.split("\\.");
    String[] string2Vals = version2.split("\\.");

    int length = Math.max(string1Vals.length, string2Vals.length);

    for (int i = 0; i < length; i++)
    {
        Integer v1 = (i < string1Vals.length)?Integer.parseInt(string1Vals[i]):0;
        Integer v2 = (i < string2Vals.length)?Integer.parseInt(string2Vals[i]):0;

        //Making sure Version1 bigger than version2
        if (v1 > v2)
        {
            return 1;
        }
        //Making sure Version1 smaller than version2
        else if(v1 < v2)
        {
            return -1;
        }
    }

    //Both are equal
    return 0;
}

【讨论】：

【解决方案19】：

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
    }
}

你可以像这样使用：

    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"))

【讨论】：

【解决方案20】：

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

【讨论】：

在计算版本之前我也忽略了字母或任何其他非数字字符

【解决方案21】：

由于此页面上没有答案可以很好地处理混合文本，因此我制作了自己的版本：

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
    }
}

但在您需要将“alpha”与“beta”进行比较的情况下，它仍然不足。

【讨论】：

【解决方案22】：

自己写了一个小函数。使用列表更简单

 public static boolean checkVersionUpdate(String olderVerison, String newVersion) {
        if (olderVerison.length() == 0 || newVersion.length() == 0) {
            return false;
        }
        List<String> newVerList = Arrays.asList(newVersion.split("\\."));
        List<String> oldVerList = Arrays.asList(olderVerison.split("\\."));

        int diff = newVerList.size() - oldVerList.size();
        List<String> newList = new ArrayList<>();
        if (diff > 0) {
            newList.addAll(oldVerList);
            for (int i = 0; i < diff; i++) {
                newList.add("0");
            }
            return examineArray(newList, newVerList, diff);
        } else if (diff < 0) {
            newList.addAll(newVerList);
            for (int i = 0; i < -diff; i++) {
                newList.add("0");
            }
            return examineArray(oldVerList, newList, diff);
        } else {
            return examineArray(oldVerList, newVerList, diff);
        }

    }

    public static boolean examineArray(List<String> oldList, List<String> newList, int diff) {
        boolean newVersionGreater = false;
        for (int i = 0; i < oldList.size(); i++) {
            if (Integer.parseInt(newList.get(i)) > Integer.parseInt(oldList.get(i))) {
                newVersionGreater = true;
                break;
            } else if (Integer.parseInt(newList.get(i)) < Integer.parseInt(oldList.get(i))) {
                newVersionGreater = false;
                break;
            } else {
                newVersionGreater = diff > 0;
            }
        }

        return newVersionGreater;
    }

【讨论】：

【解决方案23】：

我写了一个小的 Java/Android 库来比较版本号：https://github.com/G00fY2/version-compare

它的基本作用是这样的：

  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 sn-p 不提供任何错误检查或处理。除此之外，我的库还支持“1.2-rc”>“1.2-beta”等后缀。

【讨论】：

【解决方案24】：

使用 Java 8 Stream 替换组件中的前导零。这段代码通过了interviewbit.com的所有测试

public int compareVersion(String A, String B) {
    List<String> strList1 = Arrays.stream(A.split("\\."))
                                           .map(s -> s.replaceAll("^0+(?!$)", ""))
                                           .collect(Collectors.toList());
    List<String> strList2 = Arrays.stream(B.split("\\."))
                                           .map(s -> s.replaceAll("^0+(?!$)", ""))
                                           .collect(Collectors.toList());
    int len1 = strList1.size();
    int len2 = strList2.size();
    int i = 0;
    while(i < len1 && i < len2){
        if (strList1.get(i).length() > strList2.get(i).length()) return 1;
        if (strList1.get(i).length() < strList2.get(i).length()) return -1;
        int result = new Long(strList1.get(i)).compareTo(new Long(strList2.get(i)));
        if (result != 0) return result;
        i++;
    }
    while (i < len1){
        if (!strList1.get(i++).equals("0")) return 1;
    }
    while (i < len2){
        if (!strList2.get(i++).equals("0")) return -1;
    }
    return 0;
}

【讨论】：

【解决方案25】：

对于要根据版本号显示强制更新警报的人，我有以下想法。在比较 Android Current App 版本和 firebase 远程配置版本之间的版本时，可能会使用此功能。这并不完全是所问问题的答案，但这肯定会对某人有所帮助。

import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
public class Main
{
  static String firebaseVersion = "2.1.3"; // or 2.1
  static String appVersion = "2.1.4";
  static List<String> firebaseVersionArray;
  static List<String> appVersionArray;
  static boolean isNeedToShowAlert = false;
  public static void main (String[]args)
  {
    System.out.println ("Hello World");
    firebaseVersionArray = new ArrayList<String>(Arrays.asList(firebaseVersion.split ("\\.")));
    appVersionArray = new ArrayList<String>(Arrays.asList(appVersion.split ("\\.")));
    if(appVersionArray.size() < firebaseVersionArray.size()) {
        appVersionArray.add("0");
    }
    if(firebaseVersionArray.size() < appVersionArray.size()) {
        firebaseVersionArray.add("0");
    }
    isNeedToShowAlert = needToShowAlert(); //Returns false
    System.out.println (isNeedToShowAlert);

  }
  static boolean needToShowAlert() {
      boolean result = false;
      for(int i = 0 ; i < appVersionArray.size() ; i++) {
          if (Integer.parseInt(appVersionArray.get(i)) == Integer.parseInt(firebaseVersionArray.get(i))) {
              continue;
          } else if (Integer.parseInt(appVersionArray.get(i)) > Integer.parseInt(firebaseVersionArray.get(i))){
             result = false;
             break;
          } else if (Integer.parseInt(appVersionArray.get(i)) < Integer.parseInt(firebaseVersionArray.get(i))) {
             result = true;
             break;  
          }
      }
      return result;
  }
}

您可以通过复制粘贴来运行此代码 https://www.onlinegdb.com/online_java_compiler

【讨论】：

【解决方案26】：

public static void main(String[] args) {

    String version1 = "1.0";
    String version2 = "1.0.0";
    String[] version1_splits = version1.split("\\.");
    String[] version2_splits = version2.split("\\.");
    int length = version1_splits.length >= version2_splits.length ? version1_splits.length : version2_splits.length;
    int i=0;
    for(;i<length;i++){
        int version1_int = getValue(version1_splits,i);
        int version2_int = getValue(version2_splits,i);
        if(version1_int > version2_int){
            System.out.println("version1 > version2");
            break;
        }
        else if(version1_int < version2_int){
            System.out.println("version2 > version1");
            break;
        }
        else{
            if(i == length-1)
            System.out.println("version1 = version2");
        }
    }
}

private static int getValue(String[] version1_splits, int i) {
    int temp;
    try{
        temp = Integer.valueOf(version1_splits[i]);
    }
    catch(IndexOutOfBoundsException e){
        temp=0;
    }

    return temp;
}

【讨论】：

【解决方案27】：

此代码尝试解析此类比较版本。

大多数版本说明符，例如 >= 1.0，都是不言自明的。这说明符 ~> 具有特殊含义，最好通过示例来说明。 ~> 2.0.3 是等同于 >= 2.0.3 和 2.1 等同于 >= 2.1 和

public static boolean apply(String cmpDeviceVersion, String reqDeviceVersion)
{
    Boolean equal           = !cmpDeviceVersion.contains(">") && !cmpDeviceVersion.contains(">=") &&
                              !cmpDeviceVersion.contains("<") && !cmpDeviceVersion.contains("<=") &&
                              !cmpDeviceVersion.contains("~>");

    Boolean between         = cmpDeviceVersion.contains("~>");
    Boolean higher          = cmpDeviceVersion.contains(">") && !cmpDeviceVersion.contains(">=") && !cmpDeviceVersion.contains("~>");
    Boolean higherOrEqual   = cmpDeviceVersion.contains(">=");

    Boolean less            = cmpDeviceVersion.contains("<") && !cmpDeviceVersion.contains("<=");
    Boolean lessOrEqual     = cmpDeviceVersion.contains("<=");

    cmpDeviceVersion        = cmpDeviceVersion.replaceAll("[<>=~]", "");
    cmpDeviceVersion        = cmpDeviceVersion.trim();

    String[] version        = cmpDeviceVersion.split("\\.");
    String[] reqVersion     = reqDeviceVersion.split("\\.");

    if(equal)
    {
        return isEqual(version, reqVersion);
    }
    else if(between)
    {
        return isBetween(version, reqVersion);
    }
    else if(higher)
    {
        return isHigher(version, reqVersion);
    }
    else if(higherOrEqual)
    {
        return isEqual(version, reqVersion) || isHigher(version, reqVersion);
    }
    else if(less)
    {
        return isLess(version, reqVersion);
    }
    else if(lessOrEqual)
    {
        return isEqual(version, reqVersion) || isLess(version, reqVersion);
    }

    return false;
}

private static boolean isEqual(String[] version, String[] reqVersion)
{
    String strVersion = StringUtils.join(version);
    String strReqVersion = StringUtils.join(reqVersion);
    if(version.length > reqVersion.length)
    {
        Integer diff = version.length - reqVersion.length;
        strReqVersion += StringUtils.repeat(".0", diff);
    }
    else if(reqVersion.length > version.length)
    {
        Integer diff = reqVersion.length - version.length;
        strVersion += StringUtils.repeat(".0", diff);
    }

    return strVersion.equals(strReqVersion);
}

private static boolean isHigher(String[] version, String[] reqVersion)
{
    String strVersion = StringUtils.join(version);
    String strReqVersion = StringUtils.join(reqVersion);
    if(version.length > reqVersion.length)
    {
        Integer diff = version.length - reqVersion.length;
        strReqVersion += StringUtils.repeat(".0", diff);
    }
    else if(reqVersion.length > version.length)
    {
        Integer diff = reqVersion.length - version.length;
        strVersion += StringUtils.repeat(".0", diff);
    }

    return strReqVersion.compareTo(strVersion) > 0;
}

private static boolean isLess(String[] version, String[] reqVersion)
{
    String strVersion = StringUtils.join(version);
    String strReqVersion = StringUtils.join(reqVersion);
    if(version.length > reqVersion.length)
    {
        Integer diff = version.length - reqVersion.length;
        strReqVersion += StringUtils.repeat(".0", diff);
    }
    else if(reqVersion.length > version.length)
    {
        Integer diff = reqVersion.length - version.length;
        strVersion += StringUtils.repeat(".0", diff);
    }

    return strReqVersion.compareTo(strVersion) < 0;
}

private static boolean isBetween(String[] version, String[] reqVersion)
{
    return (isEqual(version, reqVersion) || isHigher(version, reqVersion)) &&
            isLess(getNextVersion(version), reqVersion);
}

private static String[] getNextVersion(String[] version)
{
    String[] nextVersion = new String[version.length];
    for(int i = version.length - 1; i >= 0 ; i--)
    {
        if(i == version.length - 1)
        {
            nextVersion[i] = "0";
        }
        else if((i == version.length - 2) && NumberUtils.isNumber(version[i]))
        {
            nextVersion[i] = String.valueOf(NumberUtils.toInt(version[i]) + 1);
        }
        else
        {
            nextVersion[i] = version[i];
        }
    }
    return nextVersion;
}

【讨论】：

【解决方案28】：

我喜欢@Peter Lawrey 的想法，并且我将其扩展到更多限制：

    /**
    * 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);
    }

希望它可以帮助某人。它通过了 interviewbit 和 leetcode 中的所有测试用例（需要在 compareVersion 函数中取消注释两行）。

容易测试！

【讨论】：

【解决方案29】：

最简单的解决方案是使用字符串比较。删除不需要的点或字母，以防版本类似于 v1.0.1Beta 使用 Regex("[^0-9]") 并且您获得 1.0 和 1.0.1 等版本：

String ver1 = "10";
String ver2 = "101";
    
int res = ver1.compareTo(ver2);
System.out.println("res: "+res);

如果 ver1 按字典顺序小于 ver2，则返回负数，如果相等则返回 0，如果 ver1 大于则返回正数.

compareTo() 方法按字典顺序比较两个字符串。

比较基于字符串中每个字符的 Unicode 值。

如果字符串等于另一个字符串，则该方法返回 0。如果字符串小于另一个字符串（更少字符），则返回小于 0 的值；如果字符串大于另一个字符串（更多字符），则返回大于 0 的值。

【讨论】：

这已经与给定样本之一中断，因为它比较 1.9 大于 1.10

【解决方案30】：

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);
    }
}

【讨论】：

使用 Java 9 的 own builtin Version class

使用 Java 9 的 own builtin `Version` class