java实现版本号比较

前言

在客户端如Android的时候会涉及到版本的比较，版本号示例

1.0.0

1.0.a1

代码实现

public class Client {

  private static int versionCompare(String version1, String version2) {
    String[] versionArr1 = version1.split("\.");
    String[] versionArr2 = version2.split("\.");
    int minLen = Math.min(versionArr1.length, versionArr2.length);
    int diff = 0;
    for (int i = 0; i < minLen; i++) {
      String v1 = versionArr1[i];
      String v2 = versionArr2[i];
      diff = v1.length() - v2.length();
      if (diff == 0) {
        diff = v1.compareTo(v2);
      }
      if (diff != 0) {
        break;
      }
    }
    diff = (diff != 0) ? diff : (versionArr1.length - versionArr2.length);
    return diff;
  }

  public static void main(String[] args) {
    System.out.println(versionCompare("1.2", "1.3"));
    System.out.println(versionCompare("1.2", "1.1"));
    System.out.println(versionCompare("1.2", "1.1.4"));
    System.out.println(versionCompare("9.9", "10.8"));
    System.out.println(versionCompare("9.a", "9.b"));
  }

}

根据点号分割，然后一级一级比较，主版本和主版本号比较，次版本号和次版本号比较。

参考

Java实现比较版本号