From a868d701d771a24207c6d40256f3bbae1207aad8 Mon Sep 17 00:00:00 2001
From: Makoto Onuki <omakoto@google.com>
Date: Wed, 8 Apr 2020 15:55:25 -0700
Subject: [PATCH] Enhance exception message on SQLiteCantOpenDatabaseException

Bug: 150248286
Test: atest CtsDatabaseTestCases
Change-Id: I39f7a3516dfbe0198b1ef5f68af1265df98c5a0a
---
 .../SQLiteCantOpenDatabaseException.java      |  5 ++++
 .../database/sqlite/SQLiteConnection.java     | 24 ++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/core/java/android/database/sqlite/SQLiteCantOpenDatabaseException.java b/core/java/android/database/sqlite/SQLiteCantOpenDatabaseException.java
index 6f01796c93c23..5d4b48dac46b9 100644
--- a/core/java/android/database/sqlite/SQLiteCantOpenDatabaseException.java
+++ b/core/java/android/database/sqlite/SQLiteCantOpenDatabaseException.java
@@ -22,4 +22,9 @@ public class SQLiteCantOpenDatabaseException extends SQLiteException {
     public SQLiteCantOpenDatabaseException(String error) {
         super(error);
     }
+
+    /** @hide */
+    public SQLiteCantOpenDatabaseException(String error, Throwable cause) {
+        super(error, cause);
+    }
 }
diff --git a/core/java/android/database/sqlite/SQLiteConnection.java b/core/java/android/database/sqlite/SQLiteConnection.java
index bcb3934a5b08e..f7c96a3a02c1c 100644
--- a/core/java/android/database/sqlite/SQLiteConnection.java
+++ b/core/java/android/database/sqlite/SQLiteConnection.java
@@ -36,6 +36,9 @@ import dalvik.system.CloseGuard;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
@@ -215,12 +218,31 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen
     }
 
     private void open() {
+        final String file = mConfiguration.path;
         final int cookie = mRecentOperations.beginOperation("open", null, null);
         try {
-            mConnectionPtr = nativeOpen(mConfiguration.path, mConfiguration.openFlags,
+            mConnectionPtr = nativeOpen(file, mConfiguration.openFlags,
                     mConfiguration.label,
                     NoPreloadHolder.DEBUG_SQL_STATEMENTS, NoPreloadHolder.DEBUG_SQL_TIME,
                     mConfiguration.lookasideSlotSize, mConfiguration.lookasideSlotCount);
+        } catch (SQLiteCantOpenDatabaseException e) {
+            String message = String.format("Cannot open database '%s'", file);
+
+            final Path path = FileSystems.getDefault().getPath(file);
+            final Path dir = path.getParent();
+
+            if (!Files.isDirectory(dir)) {
+                message += ": Directory " + dir + " doesn't exist";
+            } else if (!Files.exists(path)) {
+                message += ": File " + path + " doesn't exist";
+            } else if (!Files.isReadable(path)) {
+                message += ": File " + path + " is not readable";
+            } else if (Files.isDirectory(path)) {
+                message += ": Path " + path + " is a directory";
+            } else {
+                message += ": Unknown reason";
+            }
+            throw new SQLiteCantOpenDatabaseException(message, e);
         } finally {
             mRecentOperations.endOperation(cookie);
         }