add: значение аттбибута как список

.idea/gradle.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>

build.gradle

@@ -1,3 +1,5 @@
+//file:noinspection GroovyAssignabilityCheck
+//file:noinspection GrUnresolvedAccess
 plugins {
     id "java-library"
     id "maven-publish"
@@ -8,8 +10,13 @@ wrapper {
     distributionType = Wrapper.DistributionType.BIN
 }
 
+compileJava {
+    sourceCompatibility = targetCompatibility = JavaVersion.VERSION_17
+    options.encoding = "UTF-8"
+}
+
 group = "ru.di9"
-version = "1.0"
+version = "1.2.1"
 
 repositories {
     mavenLocal()
@@ -19,23 +26,21 @@ repositories {
 dependencies {
     api("it.unimi.dsi:fastutil:8.5.12")
 
-    def junit5_version = "5.9.2"
-    testImplementation("org.junit.jupiter:junit-jupiter-api:${junit5_version}")
-    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:${junit5_version}")
+    def junit5Version = "5.9.2"
+    testImplementation("org.junit.jupiter:junit-jupiter-api:$junit5Version")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:$junit5Version")
 }
 
 test {
     useJUnitPlatform()
 }
 
-publishing {
-    publications {
-        mavenBinary(MavenPublication) {
-            groupId = project.group
-            artifactId = project.name
-            version = project.version
+publishing.publications {
+    mavenBinary(MavenPublication) {
+        groupId = project.group
+        artifactId = project.name
+        version = project.version
 
-            from components.java
-        }
+        from components.java
     }
 }

src/main/java/ru/di9/xml/XmlElement.java

@@ -56,21 +56,38 @@ public class XmlElement implements Iterable<XmlElement> {
         return element.hasAttribute(key);
     }
 
-    public String getAttribute(String key) {
-        return element.getAttribute(key);
+    public Optional<String> getAttribute(String key) {
+        if (element.hasAttribute(key)) {
+            return Optional.of(element.getAttribute(key));
+        } else {
+            return Optional.empty();
+        }
     }
 
-    public int getAttributeAsInt(String key) {
-        var value = element.getAttribute(key);
-        return StringUtils.isEmpty(value) ? 0 : Integer.parseInt(value);
+    public OptionalInt getAttributeAsInt(String key) {
+        if (element.hasAttribute(key)) {
+            return OptionalInt.of(Integer.parseInt(element.getAttribute(key)));
+        } else {
+            return OptionalInt.empty();
+        }
     }
 
-    public boolean getAttributeAsBool(String key) {
-        var value = element.getAttribute(key);
-        return !StringUtils.isEmpty(value) && Boolean.parseBoolean(value);
+    public Optional<Boolean> getAttributeAsBool(String key) {
+        if (element.hasAttribute(key)) {
+            return Optional.of(Boolean.parseBoolean(element.getAttribute(key)));
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    public List<String> getAttributeAsListString(String key) {
+        if (element.hasAttribute(key)) {
+            return Arrays.asList(element.getAttribute(key).split(","));
+        } else {
+            return Collections.emptyList();
+        }
     }
 
-    @SuppressWarnings("NullableProblems")
     @Override
     public Iterator<XmlElement> iterator() {
         return new XmlElementIterator(element.getChildNodes());

src/test/java/ru/di9/xml/XmlElementTest.java

@@ -34,6 +34,7 @@ class XmlElementTest {
         assertEquals("root", rootElement.getTagName());
     }
 
+    @SuppressWarnings("OptionalGetWithoutIsPresent")
     @Test
     void testIterator() {
         Iterator<XmlElement> iteratorElement = rootElement.iterator();
@@ -47,13 +48,22 @@ class XmlElementTest {
 
             assertEquals(tagName, element.getTagName());
             switch (element.getTagName()) {
-                case "node_str" -> assertEquals(attr, element.getAttribute("attr"));
-                case "node_int" -> assertEquals(attr, element.getAttributeAsInt("attr"));
-                case "node_bool" -> assertEquals(attr, element.getAttributeAsBool("attr"));
+                case "node_str" -> {
+                    assertTrue(element.getAttribute("attr").isPresent());
+                    assertEquals(attr, element.getAttribute("attr").get());
+                }
+                case "node_int" -> {
+                    assertTrue(element.getAttribute("attr").isPresent());
+                    assertEquals(attr, element.getAttributeAsInt("attr").getAsInt());
+                }
+                case "node_bool" -> {
+                    assertTrue(element.getAttribute("attr").isPresent());
+                    assertEquals(attr, element.getAttributeAsBool("attr").get());
+                }
                 case "empty" -> {
                     assertTrue(StringUtils.isEmpty(element.getValue()));
                     assertFalse(element.hasAttribute("attr"));
-                    assertTrue(StringUtils.isEmpty(element.getAttribute("attr")));
+                    assertTrue(element.getAttribute("attr").isEmpty());
                 }
                 default -> fail("Unknown tag '%s'".formatted(element.getTagName()));
             }