Add extract utilities to PersistenceId (#30881)

* extract entityTypeHint and entityId from persistence id String

akka-persistence-typed/src/main/scala/akka/persistence/typed/PersistenceId.scala

@@ -124,6 +124,29 @@ object PersistenceId {
    */
   def ofUniqueId(id: String): PersistenceId =
     new PersistenceId(id)
+
+  /**
+   * Extract the `entityTypeHint` from a persistence id String with the default separator `|`.
+   * If the separator `|` is not found it return the empty String (`""`).
+   */
+  def extractEntityType(id: String): String = {
+    val i = id.indexOf(PersistenceId.DefaultSeparator)
+    if (i == -1) ""
+    else id.substring(0, i)
+  }
+
+  /**
+   * Extract the `entityId` from a persistence id String with the default separator `|`.
+   * If the separator `|` is not found it return the `id`.
+   */
+  def extractEntityId(id: String): String = {
+    val i = id.indexOf(PersistenceId.DefaultSeparator)
+    if (i == -1) id
+    else id.substring(i + 1)
+  }
+
+  def unapply(persistenceId: PersistenceId): Option[(String, String)] =
+    Some((persistenceId.entityTypeHint, persistenceId.entityId))
 }
 
 /**
@@ -137,6 +160,9 @@ final class PersistenceId private (val id: String) {
   if (id.trim.isEmpty)
     throw new IllegalArgumentException("persistenceId must not be empty")
 
+  def entityTypeHint: String = PersistenceId.extractEntityType(id)
+  def entityId: String = PersistenceId.extractEntityId(id)
+
   override def toString: String = s"PersistenceId($id)"
 
   override def hashCode(): Int = id.hashCode

akka-persistence-typed/src/test/scala/akka/persistence/typed/PersistenceIdSpec.scala

@@ -47,6 +47,27 @@ class PersistenceIdSpec extends AnyWordSpec with Matchers with LogCapturing {
         PersistenceId("SomeType", "A#B", "#")
       }
     }
+
+    "be able to extract entityTypeHint" in {
+      PersistenceId.extractEntityType("SomeType|abc") should ===("SomeType")
+      PersistenceId.extractEntityType("abc") should ===("")
+      PersistenceId("SomeType", "abc").entityTypeHint should ===("SomeType")
+    }
+
+    "be able to extract entityId" in {
+      PersistenceId.extractEntityId("SomeType|abc") should ===("abc")
+      PersistenceId.extractEntityId("abc") should ===("abc")
+      PersistenceId("SomeType", "abc").entityId should ===("abc")
+    }
+
+    "extract entityTypeHint and entityId via unapply" in {
+      PersistenceId("SomeType", "abc") match {
+        case PersistenceId(entityTypeHint, entityId) =>
+          entityTypeHint should ===("SomeType")
+          entityId should ===("abc")
+        case _ => fail()
+      }
+    }
   }
 
 }