2 files changed, 43 insertions, 0 deletions
diff --git a/core/java/android/os/Build.java b/core/java/android/os/Build.java
index e9ce759248ae..9b39c62ad03e 100644
--- a/core/java/android/os/Build.java
+++ b/core/java/android/os/Build.java
@@ -1578,6 +1578,25 @@ public class Build {
     }
 
     /**
+     * Convert an int representing a major.minor version like SDK_INT_FULL to a
+     * human readable string. The returned string is only intended for debug
+     * and error messages.
+     *
+     * @param version the int to convert to a string
+     * @return a String representing the same major.minor version as the int passed in
+     * @throws IllegalArgumentException if {@code version} is negative
+     *
+     * @hide
+     */
+    public static String fullVersionToString(@SdkIntFull int version) {
+        if (version < 0) {
+            throw new IllegalArgumentException("failed to convert '" + version
+                    + "' to string: not a valid major.minor version code");
+        }
+        return String.format("%d.%d", getMajorSdkVersion(version), getMinorSdkVersion(version));
+    }
+
+    /**
      * The vendor API for 2024 Q2
      *
      * <p>For Android 14-QPR3 and later, the vendor API level is completely decoupled from the SDK
diff --git a/core/tests/coretests/src/android/os/BuildTest.java b/core/tests/coretests/src/android/os/BuildTest.java
index 9cb2b93da6ab..2a67716aa215 100644
--- a/core/tests/coretests/src/android/os/BuildTest.java
+++ b/core/tests/coretests/src/android/os/BuildTest.java
@@ -176,4 +176,28 @@ public class BuildTest {
             Build.parseFullVersion("12.-34");
         });
     }
+
+    @Test
+    public void testFullVersionToStringCorrectInput() throws Exception {
+        assertEquals("0.0", Build.fullVersionToString(0));
+        assertEquals("1.0", Build.fullVersionToString(1 * 100000 + 0));
+        assertEquals("1.1", Build.fullVersionToString(1 * 100000 + 1));
+        assertEquals("12.34", Build.fullVersionToString(12 * 100000 + 34));
+    }
+
+    @Test
+    public void testFullVersionToStringSameStringAfterRoundTripViaParseFullVersion()
+            throws Exception {
+        String s = "12.34";
+        int major = Build.getMajorSdkVersion(Build.parseFullVersion(s));
+        int minor = Build.getMinorSdkVersion(Build.parseFullVersion(s));
+        assertEquals(s, Build.fullVersionToString(major * 100000 + minor));
+    }
+
+    @Test
+    public void testFullVersionToStringIncorrectInputNegativeVersion() throws Exception {
+        assertThrows(IllegalArgumentException.class, () -> {
+            Build.fullVersionToString(-1);
+        });
+    }
 }