[TIMOB-26954] Android: Fixed bug where File.read().text returns null …

…on Android Q (#10931)

- Modified Ti.Blob "text" property to always return text even if its a binary type, like iOS.
- Modified Ti.Blob toString() method to only return blob's text if mimetype is a known text type, like how "text" property used to work.

android/titanium/src/java/org/appcelerator/titanium/TiBlob.java

@@ -164,7 +164,7 @@ public static TiBlob blobFromImage(Bitmap image)
 	 */
 	public static TiBlob blobFromData(byte[] data)
 	{
-		return blobFromData(data, "application/octet-stream");
+		return blobFromData(data, TiMimeTypeHelper.MIME_TYPE_OCTET_STREAM);
 	}
 
 	/**
@@ -178,7 +178,7 @@ public static TiBlob blobFromData(byte[] data)
 	public static TiBlob blobFromData(byte[] data, String mimetype)
 	{
 		if (mimetype == null || mimetype.length() == 0) {
-			return new TiBlob(TYPE_DATA, data, "application/octet-stream");
+			return new TiBlob(TYPE_DATA, data, TiMimeTypeHelper.MIME_TYPE_OCTET_STREAM);
 		}
 		TiBlob blob = new TiBlob(TYPE_DATA, data, mimetype);
 		blob.loadBitmapInfo();
@@ -414,17 +414,9 @@ public String getText()
 				result = (String) data;
 			case TYPE_DATA:
 			case TYPE_FILE:
-				// Don't try to return a string if we can see the
-				// mimetype is binary, unless it's application/octet-stream, which means
-				// we don't really know what it is, so assume the user-developer knows
-				// what she's doing.
-				if (mimetype != null && TiMimeTypeHelper.isBinaryMimeType(mimetype)
-					&& !mimetype.equals("application/octet-stream")) {
-					return null;
-				}
 				try {
 					result = new String(getBytes(), "utf-8");
-				} catch (UnsupportedEncodingException e) {
+				} catch (Exception ex) {
 					Log.w(TAG, "Unable to convert to string.");
 				}
 				break;
@@ -504,13 +496,27 @@ public int getHeight()
 	@Kroll.method
 	public String toString()
 	{
-		// blob should return the text value on toString
-		// if it's not null
-		String text = getText();
-		if (text != null) {
-			return text;
+		// Determine if this blob references binary data instead of text.
+		// Note: If mime-type is "application/octet-stream", then type is unknown. Assume it is text.
+		boolean isBinary = false;
+		if ((this.mimetype != null) && TiMimeTypeHelper.isBinaryMimeType(this.mimetype)) {
+			if (!this.mimetype.equals(TiMimeTypeHelper.MIME_TYPE_OCTET_STREAM)) {
+				isBinary = true;
+			}
 		}
-		return "[object TiBlob]";
+
+		// Attempt to fetch text from the blob, but only if it's NOT a known binary type.
+		// Ex: Don't let Javascript toString() waste huge amounts of memory on a blob that wraps an image file.
+		String text = null;
+		if (!isBinary) {
+			text = getText();
+		}
+		if (text == null) {
+			text = "[object TiBlob]";
+		}
+
+		// Return the blob's text.
+		return text;
 	}
 
 	// clang-format off

android/titanium/src/java/org/appcelerator/titanium/util/TiMimeTypeHelper.java

@@ -24,6 +24,7 @@
 public class TiMimeTypeHelper
 {
 	private static final String DEFAULT_MIME_TYPE = "application/octet-stream";
+	public static final String MIME_TYPE_OCTET_STREAM = DEFAULT_MIME_TYPE;
 	public static final String MIME_TYPE_JAVASCRIPT = "text/javascript";
 	public static final String MIME_TYPE_HTML = "text/html";
 	public static final HashMap<String, String> EXTRA_MIMETYPES = new HashMap<String, String>();
@@ -248,19 +249,27 @@ public static String getFileExtensionFromMimeType(String mimeType, String defaul
 
 	public static boolean isBinaryMimeType(String mimeType)
 	{
-		if (mimeType != null) {
+		boolean isBinary = false;
+		if ((mimeType != null) && !mimeType.isEmpty()) {
 			String parts[] = mimeType.split(";");
 			mimeType = parts[0];
 
-			if (mimeType.startsWith("application/") && !mimeType.endsWith("xml")) {
-				return true;
-			} else if (mimeType.startsWith("image/") && !mimeType.endsWith("xml")) {
-				return true;
-			} else if (mimeType.startsWith("audio/") || mimeType.startsWith("video/")) {
-				return true;
-			} else
-				return false;
+			if (mimeType.startsWith("application/")) {
+				if (!mimeType.endsWith("xml") && !mimeType.endsWith("json")) {
+					isBinary = true;
+				}
+			} else if (mimeType.startsWith("image/")) {
+				if (!mimeType.endsWith("xml")) {
+					isBinary = true;
+				}
+			} else if (mimeType.startsWith("audio/")) {
+				isBinary = true;
+			} else if (mimeType.startsWith("font/")) {
+				isBinary = true;
+			} else if (mimeType.startsWith("video/")) {
+				isBinary = true;
+			}
 		}
-		return false;
+		return isBinary;
 	}
 }