Set the TextRecognizer's Processor.

MainActivity.java

textRecognizer.setProcessor(new Detector.Processor<TextBlock>() {
                @Override
                public void release() {
                }

                /**
                 * Detect all the text from camera using TextBlock and the save values into a stringBuilder
                 * which will then be set to the textView.
                 * */
                @Override
                public void receiveDetections(Detector.Detections<TextBlock> detections) {
                    final SparseArray<TextBlock> items = detections.getDetectedItems();
                    if (items.size() != 0 ){
                        mTextView.post(new Runnable() {
                            @Override
                            public void run() {
                                StringBuilder stringBuilder = new StringBuilder();
                                for(int i=0;i<items.size();i++){
                                    TextBlock item = items.valueAt(i);
                                    stringBuilder.append(item.getValue());
                                    stringBuilder.append("\n");
                                }
                                // set the stringBuilder value to textView
                                mTextView.setText(stringBuilder.toString());
                            }
                        });
                    }
                }
            });