Sample Code for AWS Textract Key-Value Extraction JAVA AWS SDK --- Tekraze

key-value-extract.java

      
    public Map<String, String> getKeyValueRelationShipByBlocks(List<Block> blocks) {
        Map<String, Map<String, Block>> keyValueBlockMap = getKeyValueBlockMap(blocks);
        getKeyValueRelationShip(keyValueBlockMap);
        return null;
    }

    Block findValueBlock(Block keyBlock, Map<String, Block> valueMap) {
        log.debug("Find value Block ");
        Block valueBlock = null;
        for (Relationship relationShip : keyBlock.getRelationships()) {
            if (relationShip.getType().equalsIgnoreCase("VALUE")) {
                for (String id : relationShip.getIds()) {
                    valueBlock = valueMap.get(id);
                    return valueBlock;
                }
            }
        }
        return valueBlock;
    }

    Map<String, String> getKeyValueRelationShip(Map<String, Map<String, Block>> keyValueBlockMap) {
        log.debug("Get Key Value Relationship {}", keyValueBlockMap);
        Map<String, String> keyValueRelationShip = new HashMap<>();
        Map<String, Block> keyMap = keyValueBlockMap.get("keyMap");
        Map<String, Block> valueMap = keyValueBlockMap.get("valueMap");
        Map<String, Block> blocksMap = keyValueBlockMap.get("blockMap");
        keyMap.forEach((blockId, keyBlock) -> {
            Block valueBlock = findValueBlock(keyBlock, valueMap);
            String key = getBlockText(keyBlock, blocksMap);
            String val = getBlockText(valueBlock, blocksMap);
            keyValueRelationShip.put(key, val);
        });
        return keyValueRelationShip;
    }

    String getBlockText(Block resultBlock, Map<String, Block> blocksMap) {
        log.debug("getBlockText");
        String blockText = "";
        List<Relationship> relationShips = resultBlock.getRelationships();
        if (relationShips != null) {
            for (Relationship relationship : relationShips) {
                if (relationship.getType().equals("CHILD")) {
                    // relationship.getIds().forEach(childId ->
                    for (String childId : relationship.getIds()) {
                        Block wordBlock = blocksMap.get(childId);
                        if (wordBlock.getBlockType().equals("WORD")) {
                            blockText = wordBlock.getText() + " ";
                        }
                        if (wordBlock.getBlockType().equals("SELECTION_ELEMENT")) {
                            if (wordBlock.getSelectionStatus().equals("SELECTED")) {
                                blockText += "X ";
                            }
                        }
                    }
                    ;
                }
            }
        }
        return blockText;
    }

    Map<String, Map<String, Block>> getKeyValueBlockMap(List<Block> blocks) {
        log.debug("Create Key Value Map from A Textract Blocks List", blocks);
        // # get key and value maps
        Map<String, Map<String, Block>> keyValueBlockMap = new HashMap<String, Map<String, Block>>();
        Map<String, Block> keyMap = new HashMap<>();
        Map<String, Block> valueMap = new HashMap<>();
        Map<String, Block> blockMap = new HashMap<>();
        // for block in blocks:
        for (Block block : blocks) {
            String blockId = block.getId();
            blockMap.put(blockId, block);
            if (block.getBlockType().equals("KEY_VALUE_SET")) {
                if (block.getEntityTypes().contains("KEY")) {
                    keyMap.put(blockId, block);
                } else {
                    valueMap.put(blockId, block);
                }
            }
        }
        keyValueBlockMap.put("keyMap", keyMap);
        keyValueBlockMap.put("valueMap", valueMap);
        keyValueBlockMap.put("blockMap", blockMap);
        return keyValueBlockMap;
    }

this works for me and very understandable code