Reputation: 235
I am using Jackson's YAML parser and I want to parse a YAML file without having to manually create a Java class that matches the yaml file. All the examples I can find map it to an object such as here: https://www.baeldung.com/jackson-yaml
The yaml file that is given to me will not always be the same so I need to parse it during runtime, is it possible to achieve this with jackson-yaml?
Upvotes: 2
Views: 3622
Reputation: 299178
If you don't know the exact format, you're going to have to parse the data to a tree and process it manually, which can be tedious. I'd use Optional for mapping and filtering.
Example:
public static final String YAML = "invoice: 34843\n"
+ "date : 2001-01-23\n"
+ "product:\n"
+ " - sku : BL394D\n"
+ " quantity : 4\n"
+ " description : Basketball\n"
+ " price : 450.00\n"
+ " - sku : BL4438H\n"
+ " quantity : 1\n"
+ " description : Super Hoop\n"
+ " price : 2392.00\n"
+ "tax : 251.42\n"
+ "total: 4443.52\n";
public static void main(String[] args) throws IOException {
ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory());
JsonNode jsonNode = objectMapper.readTree(YAML);
Optional.of(jsonNode)
.map(j -> j.get("product"))
.filter(ArrayNode.class::isInstance)
.map(ArrayNode.class::cast)
.ifPresent(projectArray -> projectArray.forEach(System.out::println));
}
Output:
{"sku":"BL394D","quantity":4,"description":"Basketball","price":450.0}
{"sku":"BL4438H","quantity":1,"description":"Super Hoop","price":2392.0}
Upvotes: 4
Reputation: 159185
Like when you are parsing JSON, you can parse into a Map
:
Example
ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
@SuppressWarnings("unchecked")
Map<String, Object> map = mapper.readValue(new File("test.yaml"), Map.class);
System.out.println(map);
test.yaml
orderNo: A001
date: 2019-04-17
customerName: Customer, Joe
orderLines:
- item: No. 9 Sprockets
quantity: 12
unitPrice: 1.23
- item: Widget (10mm)
quantity: 4
unitPrice: 3.45
Output
{orderNo=A001, date=2019-04-17, customerName=Customer, Joe, orderLines=[{item=No. 9 Sprockets, quantity=12, unitPrice=1.23}, {item=Widget (10mm), quantity=4, unitPrice=3.45}]}
Upvotes: 6