How to get data from tables using java code - amazon DynamoDB

public void listAllCourses(@QueryParam("author") String authorQuery) {
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("Listing all courses.");
    }
    //List<Minilibrary> Minilibrary= new ArrayList<>();
    AmazonDynamoDB amazonDynamoDB = DynamoDbResource.createClient();
    Map<String, AttributeValue> expValues = new HashMap<>();
    expValues.put(":a", new AttributeValue(authorQuery));
    QueryRequest queryRequest = new QueryRequest(TABLE_NAME);
    // queryRequest.setKeyConditionExpression("author=:a");
    HashMap<String, Condition> keyConditions = new HashMap<String, Condition>();
    keyConditions.put("Id", new Condition().withComparisonOperator(ComparisonOperator.CONTAINS)
            .withAttributeValueList(new AttributeValue("Id = 5")));
    queryRequest.setKeyConditions(keyConditions);

}