Get list of keys in Complex JSON Object (Java 8)
问题
https://stackoverflow.com/questions/64011499/get-list-of-keys-in-complex-json-object-java-8
I am dealing with a JSON that looks like this :-
{
"key1": {
"key1.1": {
"nestedkey1": "something",
"nestedkey2": "something",
"nestedkey3": "Something"
},
"key1.2": {
"nestedkey1": "something",
"nestedkey2": "something",
"nestedkey3": "Something"
}
},
"key2": {
"key2.1": {
"nestedkey1": "something",
"nestedkey2": "something",
"nestedkey3": "Something"
},
"key2.2": {
"nestedkey1": "something",
"nestedkey2": "something",
"nestedkey3": "Something"
}
}...
And I don't know all the keys. I wish to obtain all the keys so that I can create a Map<String, Object> out of this. That map should look something like ("key1" ->Corresponding object)...
Is there a simple way to do this in Java?
解答
将不确定层级的json记录，输出所有层级的字段名。用Java 实现代码较长。
用Java 下的开源包 SPL 很容易写，只要 3 行：
A |
B |
|
1 |
=i=0,json(file("records.json").read()) |
|
2 |
func recurse(r) |
>i+=1,r.fno().run(tmp=eval("r.#"/~),B1=B1.to(:i-1)|r.fname(~),output(B1.concat("->")),if(ifr(tmp),func(recurse,tmp),(B1=B1|tmp))) |
3 |
=func(recurse,A1) |
|
SPL 提供了 JDBC 供 Java 调用，把上面的脚本存为 jsonkeys.splx，在 Java 中以存储过程的方式调用脚本文件：
…
Class.forName("com.esproc.jdbc.InternalDriver");
con= DriverManager.getConnection("jdbc:esproc:local://");
st = con.prepareCall("call jsonkeys()");
st.execute();
…
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