Read message file as stream

app/src/main/java/eu/faircode/email/Helper.java

@@ -67,7 +67,7 @@ import com.sun.mail.iap.ConnectionException;
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.BufferedWriter;
-import java.io.DataInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -510,12 +510,17 @@ public class Helper {
         }
     }
 
+    static String readStream(InputStream is, String charset) throws IOException {
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        byte[] buffer = new byte[16384];
+        for (int len = is.read(buffer); len != -1; len = is.read(buffer))
+            os.write(buffer, 0, len);
+        return new String(os.toByteArray(), charset);
+    }
+
     static String readText(File file) throws IOException {
         try (FileInputStream in = new FileInputStream(file)) {
-            byte[] buffer = new byte[(int) file.length()];
-            DataInputStream dis = new DataInputStream(in);
-            dis.readFully(buffer);
-            return new String(buffer);
+            return readStream(in, "UTF-8");
         }
     }
 

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -29,7 +29,6 @@ import com.sun.mail.util.MessageRemovedIOException;
 
 import java.io.BufferedOutputStream;
 import java.io.BufferedReader;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.FileReader;
@@ -801,7 +800,7 @@ public class MessageHelper {
                     result = (String) content;
                 else if (content instanceof InputStream)
                     // Typically com.sun.mail.util.QPDecoderStream
-                    result = readStream((InputStream) content, "UTF-8");
+                    result = Helper.readStream((InputStream) content, "UTF-8");
                 else
                     result = content.toString();
             } catch (IOException | FolderClosedException | MessageRemovedException ex) {
@@ -1112,14 +1111,6 @@ public class MessageHelper {
         }
     }
 
-    private static String readStream(InputStream is, String charset) throws IOException {
-        ByteArrayOutputStream os = new ByteArrayOutputStream();
-        byte[] buffer = new byte[4096];
-        for (int len = is.read(buffer); len != -1; len = is.read(buffer))
-            os.write(buffer, 0, len);
-        return new String(os.toByteArray(), charset);
-    }
-
     static boolean equal(Address[] a1, Address[] a2) {
         if (a1 == null && a2 == null)
             return true;