JsonUtil.parseJson("[]") results in a ClassCastException

[Bruce MacDonald]

The result of calling JsonUtil.parseJson("[]") is:

java.lang.ClassCastException: java.util.ArrayList cannot be cast to org.jose4j.json.JsonUtil$DupeKeyDisallowingLinkedHashMap
    at org.jose4j.json.JsonUtil.parseJson(JsonUtil.java:62) ~[jose4j.jar:?]

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The JsonUtil class assumes that the parsed JSON will result in a map, but an empty array "[]" results in an ArrayList. This causes a ClassCastException as the Arraylist returned cannot be cast as a LinkedHashMap.

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The validity of this bug depends on if you consider [] to be valid JSON, but you may want to handle this exception in any case.

[Brian Campbell]

It is valid JSON but JsonUtil isn’t intended to be a general JSON processor. It’s a utility in support of JOSE/JWT functionality and JOSE/JWT JSON is always an JSON Object at the root. JsonUtil is designed for that.

[Bruce MacDonald]

Thanks Brian

[Brian Campbell]

a better error message could be worthwhile here

[Brian Campbell]

29ab923 somewhat more better error message when the root of the parsed JSON isn't an object (issue #142)

[Brian Campbell]

released in jose4j-0.7.0 https://bitbucket.org/b_c/jose4j/wiki/Release%20Notes#!jose4j-070-january-17-2019