2 files changed, 19 insertions, 5 deletions
diff --git a/services/backup/java/com/android/server/backup/DataChangedJournal.java b/services/backup/java/com/android/server/backup/DataChangedJournal.java
index e0bb02bdee43..c8a98554b045 100644
--- a/services/backup/java/com/android/server/backup/DataChangedJournal.java
+++ b/services/backup/java/com/android/server/backup/DataChangedJournal.java
@@ -16,6 +16,7 @@
 
 package com.android.server.backup;
 
+import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.util.Slog;
 
@@ -27,6 +28,7 @@ import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Consumer;
 
 /**
@@ -50,8 +52,8 @@ public final class DataChangedJournal {
     /**
      * Constructs an instance that reads from and writes to the given file.
      */
-    DataChangedJournal(File file) {
-        mFile = file;
+    DataChangedJournal(@NonNull File file) {
+        mFile = Objects.requireNonNull(file);
     }
 
 
@@ -133,9 +135,10 @@ public final class DataChangedJournal {
      * @return The journal.
      * @throws IOException if there is an IO error creating the file.
      */
-    static DataChangedJournal newJournal(File journalDirectory) throws IOException {
-        return new DataChangedJournal(
-                File.createTempFile(FILE_NAME_PREFIX, null, journalDirectory));
+    static DataChangedJournal newJournal(@NonNull File journalDirectory) throws IOException {
+        Objects.requireNonNull(journalDirectory);
+        File file = File.createTempFile(FILE_NAME_PREFIX, null, journalDirectory);
+        return new DataChangedJournal(file);
     }
 
     /**
diff --git a/services/tests/servicestests/src/com/android/server/backup/DataChangedJournalTest.java b/services/tests/servicestests/src/com/android/server/backup/DataChangedJournalTest.java
index 7aa111250cac..9daa4ba3c9c8 100644
--- a/services/tests/servicestests/src/com/android/server/backup/DataChangedJournalTest.java
+++ b/services/tests/servicestests/src/com/android/server/backup/DataChangedJournalTest.java
@@ -39,6 +39,7 @@ import org.mockito.MockitoAnnotations;
 import java.io.DataInputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.IOException;
 import java.util.function.Consumer;
 
 @SmallTest
@@ -134,6 +135,16 @@ public class DataChangedJournalTest {
         assertThat(folder.listFiles()).hasLength(1);
     }
 
+    @Test(expected = NullPointerException.class)
+    public void newJournal_nullJournalDir() throws IOException {
+        DataChangedJournal.newJournal(null);
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void nullFile() {
+        new DataChangedJournal(null);
+    }
+
     @Test
     public void toString_isSameAsFileToString() throws Exception {
         assertThat(mJournal.toString()).isEqualTo(mFile.toString());