refactor: 优化 SemVer 实现

plusone-commons/src/main/java/xyz/zhouxy/plusone/commons/model/SemVer.java

@@ -30,9 +30,7 @@ import com.google.common.base.Splitter;
 
 import xyz.zhouxy.plusone.commons.util.StringTools;
 
-// TODO [优化] 优化正则表达式
 // TODO [补充] 完善单元测试
-// TODO [doc] javadoc、README.md
 
 /**
  * SemVer 语义版本号
@@ -48,23 +46,42 @@ public class SemVer implements Comparable<SemVer>, Serializable {
     private final String value;
 
     private final int[] versionNumbers;
-    private final String[] preReleaseVersion;
+    @Nullable
+    private final String preReleaseVersion;
+    @Nullable
     private final String buildMetadata;
 
     private static final String VERSION_NUMBERS = "(?<numbers>(?<major>0|[1-9]\\d*)\\.(?<minor>0|[1-9]\\d*)\\.(?<patch>0|[1-9]\\d*)(\\.(0|[1-9]\\d*)){0,2})";
-    private static final String PRE_RELEASE_VERSION = "(?:-(?<prerelease>(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?";
-    private static final String BUILD_METADATA = "(?:\\+(?<buildmetadata>[0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?";
+    private static final String PRE_RELEASE_VERSION = "(?:-(?<prerelease>(?:0|[1-9]\\d{0,41}|\\d{0,18}[a-zA-Z-][0-9a-zA-Z-]{0,18})(?:\\.(?:0|[1-9]\\d{0,41}|\\d{0,18}[a-zA-Z-][0-9a-zA-Z-]{0,18})){0,18}))?";
+    private static final String BUILD_METADATA = "(?:\\+(?<buildmetadata>[0-9a-zA-Z-]{1,18}(?:\\.[0-9a-zA-Z-]{1,18}){0,18}))?";
 
     private static final Pattern PATTERN = Pattern.compile(
             "^" + VERSION_NUMBERS + PRE_RELEASE_VERSION + BUILD_METADATA + "$");
 
-    private SemVer(String value, int[] versionNumbers, @Nullable String[] preReleaseVersion, @Nullable String buildMetadata) {
+    /**
+     * 创建语义化版本号的值对象
+     *
+     * @param value 字符串值
+     * @param versionNumbers 主版本号、次版本号、修订号
+     * @param preReleaseVersion 先行版本号
+     * @param buildMetadata 版本编译信息
+     */
+    private SemVer(String value,
+            int[] versionNumbers,
+            @Nullable String preReleaseVersion,
+            @Nullable String buildMetadata) {
         this.value = value;
         this.versionNumbers = versionNumbers;
         this.preReleaseVersion = preReleaseVersion;
         this.buildMetadata = buildMetadata;
     }
 
+    /**
+     * 创建 SemVer 对象
+     *
+     * @param value 语义化版本号
+     * @return SemVer 对象
+     */
     public static SemVer of(final String value) {
         checkArgument(StringTools.isNotBlank(value), "版本号不能为空");
         final Matcher matcher = PATTERN.matcher(value);
@@ -81,30 +98,57 @@ public class SemVer implements Comparable<SemVer>, Serializable {
                 // 必须都是数字
                 .mapToInt(Integer::parseInt)
                 .toArray();
-
-        final String[] preReleaseVersion = preReleaseVersionPart != null
-                ? Splitter.on('.').splitToStream(preReleaseVersionPart).toArray(String[]::new)
-                : null;
-
-        return new SemVer(value, versionNumbers, preReleaseVersion, buildMetadataPart);
+        return new SemVer(value, versionNumbers, preReleaseVersionPart, buildMetadataPart);
     }
 
+    /**
+     * 获取主版本号
+     *
+     * @return 主版本号
+     */
     public int getMajor() {
         return this.versionNumbers[0];
     }
 
+    /**
+     * 获取次版本号
+     *
+     * @return 次版本号
+     */
     public int getMinor() {
         return this.versionNumbers[1];
     }
 
+    /**
+     * 获取修订号
+     *
+     * @return 修订号
+     */
     public int getPatch() {
         return this.versionNumbers[2];
     }
 
+    /**
+     * 获取先行版本号
+     *
+     * @return 先行版本号
+     */
+    @Nullable
+    public String getPreReleaseVersion() {
+        return this.preReleaseVersion;
+    }
+
+    /**
+     * 获取版本编译信息
+     *
+     * @return 版本编译信息
+     */
+    @Nullable
     public String getBuildMetadata() {
         return buildMetadata;
     }
 
+    /** {@inheritDoc} */
     @Override
     public int compareTo(@Nullable SemVer that) {
         if (that == null) {
@@ -117,22 +161,26 @@ public class SemVer implements Comparable<SemVer>, Serializable {
         return comparePreReleaseVersion(that);
     }
 
+    /**
+     * 获取字符串值
+     *
+     * @return 版本字符串
+     */
     public String getValue() {
         return value;
     }
 
-
-
+    /** {@inheritDoc} */
     @Override
     public int hashCode() {
         final int prime = 31;
         int result = 1;
         result = prime * result + Arrays.hashCode(versionNumbers);
-        result = prime * result + Arrays.hashCode(preReleaseVersion);
-        result = prime * result + Objects.hash(value, buildMetadata);
+        result = prime * result + Objects.hash(value, preReleaseVersion, buildMetadata);
         return result;
     }
 
+    /** {@inheritDoc} */
     @Override
     public boolean equals(@Nullable Object obj) {
         if (this == obj)
@@ -141,15 +189,21 @@ public class SemVer implements Comparable<SemVer>, Serializable {
             return false;
         SemVer other = (SemVer) obj;
         return Objects.equals(value, other.value) && Arrays.equals(versionNumbers, other.versionNumbers)
-                && Arrays.equals(preReleaseVersion, other.preReleaseVersion)
+                && Objects.equals(preReleaseVersion, other.preReleaseVersion)
                 && Objects.equals(buildMetadata, other.buildMetadata);
     }
 
+    /**
+     * 获取 SemVer 的字符串表示。如 {@code v1.2.3-alpha.1+build.1234}
+     */
     @Override
     public String toString() {
         return 'v' + value;
     }
 
+    /**
+     * 比较主版本号、次版本号、修订号
+     */
     private int compareVersionNumbers(SemVer that) {
         final int minLength = Integer.min(this.versionNumbers.length, that.versionNumbers.length);
 
@@ -163,15 +217,24 @@ public class SemVer implements Comparable<SemVer>, Serializable {
         return this.versionNumbers.length - that.versionNumbers.length;
     }
 
+    /**
+     * 比较先行版本号
+     */
     private int comparePreReleaseVersion(SemVer that) {
-        final String[] preReleaseVersionOfThis = this.preReleaseVersion;
-        final String[] preReleaseVersionOfThat = that.preReleaseVersion;
-        byte thisWithoutPreReleaseVersionFlag = preReleaseVersionOfThis == null ? (byte) 1 : (byte) 0;
-        byte thatWithoutPreReleaseVersionFlag = preReleaseVersionOfThat == null ? (byte) 1 : (byte) 0;
-        if ((thisWithoutPreReleaseVersionFlag | thatWithoutPreReleaseVersionFlag) == 1) {
+        int thisWithoutPreReleaseVersionFlag = bool2Int(this.preReleaseVersion == null);
+        int thatWithoutPreReleaseVersionFlag = bool2Int(that.preReleaseVersion == null);
+        if (isTrue(thisWithoutPreReleaseVersionFlag | thatWithoutPreReleaseVersionFlag)) {
             return thisWithoutPreReleaseVersionFlag - thatWithoutPreReleaseVersionFlag;
         }
-        @SuppressWarnings("null")
+
+        Splitter splitter = Splitter.on('.');
+
+        final String[] preReleaseVersionOfThis = splitter
+                .splitToStream(this.preReleaseVersion) // NOSONAR
+                .toArray(String[]::new);
+        final String[] preReleaseVersionOfThat = splitter
+                .splitToStream(that.preReleaseVersion) // NOSONAR
+                .toArray(String[]::new);
         final int minLength = Integer.min(preReleaseVersionOfThis.length, preReleaseVersionOfThat.length);
         for (int i = 0; i < minLength; i++) {
             int r = comparePartOfPreReleaseVersion(preReleaseVersionOfThis[i], preReleaseVersionOfThat[i]);
@@ -182,6 +245,9 @@ public class SemVer implements Comparable<SemVer>, Serializable {
         return preReleaseVersionOfThis.length - preReleaseVersionOfThat.length;
     }
 
+    /**
+     * 比较先行版本号的组成部分
+     */
     private static int comparePartOfPreReleaseVersion(String p1, String p2) {
         boolean p1IsNumber = isAllDigits(p1);
         boolean p2IsNumber = isAllDigits(p2);
@@ -195,11 +261,10 @@ public class SemVer implements Comparable<SemVer>, Serializable {
         return p2IsNumber ? 1 : p1.compareTo(p2);
     }
 
-    private static boolean isAllDigits(@Nullable String str) {
-        if (str == null || str.isEmpty()) {
-            return false;
-        }
-
+    /**
+     * 判断字符串是否全为数字
+     */
+    private static boolean isAllDigits(String str) {
         for (int i = 0; i < str.length(); i++) {
             char c = str.charAt(i);
             if (c < '0' || c > '9') {
@@ -208,4 +273,12 @@ public class SemVer implements Comparable<SemVer>, Serializable {
         }
         return true;
     }
+
+    private static int bool2Int(boolean expression) {
+        return expression ? 1 : 0;
+    }
+
+    private static boolean isTrue(int b) {
+        return b != 0;
+    }
 }