.withProjectionExpression("document.next_haircut"))
;
System.out.println(partialDocItem);
// Output: { Item: {document={next_haircut={month=10, year=2014, day=30}}} }
// I can update part of a document. Here's how I would change my current_city back to Seattle:
table.updateItem(new UpdateItemSpec()
.withPrimaryKey(HASH_KEY_NAME, "howToPutItems_withJSONDoc", RANGE_KEY_NAME, 1)
.withUpdateExpression("SET document.current_city = :city")
.withValueMap(new ValueMap().withString(":city", "Seattle"))
);
// Retrieve the entire item