src/main/java/org/embulk/input/gcs/GcsFileInput.java in embulk-input-gcs-0.3.1 vs src/main/java/org/embulk/input/gcs/GcsFileInput.java in embulk-input-gcs-0.3.2

@@ -78,20 +78,28 @@
             LOG.warn(e.getMessage());
         }
         return builder.build();
     }
 
-    // String nextToken = base64Encode(0x0a + 0x01~0x27 + filePath);
+    // String nextToken = base64Encode(0x0a + ASCII character according to utf8EncodeLength position+ filePath);
     @VisibleForTesting
     static String base64Encode(String path)
     {
         byte[] encoding;
         byte[] utf8 = path.getBytes(Charsets.UTF_8);
         LOG.debug("path string: {} ,path length:{} \" + ", path, utf8.length);
 
+        int utf8EncodeLength = utf8.length;
+        if (utf8EncodeLength >= 128) {
+            throw new ConfigException(String.format("last_path '%s' is too long to encode. Please try to reduce its length", path));
+        }
+
         encoding = new byte[utf8.length + 2];
         encoding[0] = 0x0a;
-        encoding[1] = Byte.valueOf(String.valueOf(path.length()));
+
+        // for example: 60 -> '<'
+        char temp = (char) utf8EncodeLength;
+        encoding[1] = (byte) temp;
         System.arraycopy(utf8, 0, encoding, 2, utf8.length);
 
         String s = BaseEncoding.base64().encode(encoding);
         LOG.debug("last_path(base64 encoded): {}", s);
         return s;