JSON to Java Class

Paste JSON, get Java classes that compile: field names camelCased, nested objects as static inner classes, and a @JsonProperty added wherever the key would not be a legal identifier.

The usual failure mode of this kind of tool is code that looks right and deserialises to all nulls. It almost always comes down to field names: Java identifiers do not allow -, @ or a leading digit, while JSON keys allow anything. So the rule here is strict — whenever the key and the field name differ, a @JsonProperty("original key") is emitted. With "no annotations" selected that mapping is skipped, and if a key is illegal the page says so instead of pretending it worked.

Types are inferred from values, and there are three things it cannot know. null becomes Object — there is no way to tell whether it should have been a string or a nested object. An empty array becomes List<Object> — there are no elements to look at. Integers pick between Integer and Long by range. Switch to the Long / BigDecimal mode when it matters: do not use Double for money, since the old 0.1 + 0.2 problem is a real one when the number is currency.

Nesting is flattened. Every nested type becomes a public static class of the root class rather than a deep chain — Java's static inner classes can refer to siblings, so flattening avoids the scope surprises of classes nested inside classes. The cost is that names must be unique at that level; duplicates get a numeric suffix.

Fields are unioned across array elements. If the first orders entry has items and the second does not, the field is still generated once; the missing one is simply null at runtime. The tool will not invent a default.