Duplicate key in YAML configuaration file

spring-boot yaml snakeyaml

user5591691 · Dec 6, 2017 · Viewed 12.6k times · Source

Have the following in YAML-

key1
  key2: "value"

key1
  key2
    key3: "value2"

Get exception duplicate key key1. Caused by: org.yaml.snakeyaml.parser.ParserException: while parsing MappingNode

Trying various combinations but unable to parse it correctly.

Could someone please help or guide here.

Thanks

Answer

Your YAML is syntactically invalid, but I am assuming it actually looks like this:

key1:
  key2: "value"

key1:
  key2:
    key3: "value2"

Your error is that key1 is used two times as mapping key in the root node. This is illegal as per YAML spec:

The content of a mapping node is an unordered set of key: value node pairs, with the restriction that each of the keys is unique.

The solution is to make all keys of the same mapping unique:

key11:
  key2: "value"

key12:
  key2:
    key3: "value2"