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
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'
其他回答
最好的方法是重用现有代码, 使用Maven的ComparableVersion类
优点:
Apache许可证,版本2.0, 测试, 在多个项目中使用(复制),如spring-security-core, jboss等 多个特性 它已经是java.lang。可比的了 只是复制粘贴一个类,没有第三方依赖
不要包含对maven-artifact的依赖项,因为那会拉动各种传递依赖项
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。
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:)
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);
}
}
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'