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
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。
其他回答
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;
}
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;
}
对于要显示基于版本号的强制更新警报的人,我有以下想法。这可能用于比较Android当前应用版本和firebase远程配置版本之间的版本。这并不是问题的确切答案,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
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。