Add VKey to String and String to VKey methods (#1396)

* Add stringify and parse methods to SerializeUTils

* Improve comments and test cases

* Fix comments and test strings

* Fix dependency warning

util/src/main/java/google/registry/util/SerializeUtils.java

@@ -22,7 +22,9 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import javax.annotation.Nullable;
+import org.apache.commons.codec.binary.Base64;
 
 /** Utilities for easy serialization with informative error messages. */
 public final class SerializeUtils {
@@ -47,7 +49,7 @@ public final class SerializeUtils {
   }
 
   /**
-   * Turns a byte array into an object.
+   * Turns a byte string into an object.
    *
    * @return deserialized object or {@code null} if {@code objectBytes} is {@code null}
    */
@@ -71,4 +73,19 @@ public final class SerializeUtils {
   }
 
   private SerializeUtils() {}
+
+  /** Turns an object into an encoded string that can be used safely as a URI query parameter. */
+  public static String stringify(Serializable object) {
+    checkNotNull(object, "Object cannot be null");
+    return Base64.encodeBase64URLSafeString(SerializeUtils.serialize(object));
+  }
+
+  /** Turns a string encoded by stringify() into an object. */
+  @Nullable
+  public static <T> T parse(Class<T> type, String objectString) {
+    checkNotNull(type, "Class type is not specified");
+    checkNotNull(objectString, "Object string cannot be null");
+
+    return SerializeUtils.deserialize(type, Base64.decodeBase64(objectString));
+  }
 }

util/src/test/java/google/registry/util/SerializeUtilsTest.java

@@ -16,9 +16,12 @@ package google.registry.util;
 
 import static com.google.common.truth.Truth.assertThat;
 import static google.registry.util.SerializeUtils.deserialize;
+import static google.registry.util.SerializeUtils.parse;
 import static google.registry.util.SerializeUtils.serialize;
+import static google.registry.util.SerializeUtils.stringify;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import java.io.Serializable;
 import org.junit.jupiter.api.Test;
 
 /** Unit tests for {@link SerializeUtils}. */
@@ -61,4 +64,51 @@ class SerializeUtilsTest {
             () -> deserialize(String.class, new byte[] {(byte) 0xff}));
     assertThat(thrown).hasMessageThat().contains("Unable to deserialize: objectBytes=FF");
   }
+
+  @Test
+  void testStringify_string_returnsBase64EncodedString() {
+    assertThat(stringify("foo")).isEqualTo("rO0ABXQAA2Zvbw");
+  }
+
+  @Test
+  void testParse_stringClass_returnsObject() {
+    assertThat(parse(String.class, "rO0ABXQAA2Zvbw")).isEqualTo("foo");
+  }
+
+  @Test
+  void testStringifyParse_stringValue_maintainsValue() {
+    assertThat(parse(Serializable.class, stringify("hello"))).isEqualTo("hello");
+  }
+
+  @Test
+  void testStringifyParse_longValue_maintainsValue() {
+    assertThat(parse(Serializable.class, stringify((long) 12345))).isEqualTo((long) 12345);
+  }
+
+  @Test
+  void testStringify_nullValue_throwsException() {
+    NullPointerException thrown = assertThrows(NullPointerException.class, () -> stringify(null));
+    assertThat(thrown).hasMessageThat().contains("Object cannot be null");
+  }
+
+  @Test
+  void testParse_nullClass_throwsException() {
+    NullPointerException thrown =
+        assertThrows(NullPointerException.class, () -> parse(null, "test"));
+    assertThat(thrown).hasMessageThat().contains("Class type is not specified");
+  }
+
+  @Test
+  void testParse_invalidBase64String_throwsException() {
+    IllegalArgumentException thrown =
+        assertThrows(IllegalArgumentException.class, () -> parse(String.class, "abcde:atest"));
+    assertThat(thrown).hasMessageThat().contains("Unable to deserialize");
+  }
+
+  @Test
+  void testParse_nullObjectStringValue_throwsException() {
+    NullPointerException thrown =
+        assertThrows(NullPointerException.class, () -> parse(String.class, null));
+    assertThat(thrown).hasMessageThat().contains("Object string cannot be null");
+  }
 }