quickxml_to_serde用来将xml转换为serde_json能干活：

use quickxml_to_serde::xml_string_to_json as xml2json;
use serde_json::{self, json, Value};

fn main() -> Result<(), ::std::io::Error> {
    let xml = r#"<xml><tag1 att1 = "test">
    <tag2><!--Test comment-->Test</tag2>
    <tag2>
        Test 2
    </tag2>
</tag1></xml>"#.into();
    let json: Value = xml2json(xml);
    println!("{:?}", json);
    println!("{:?}", json.to_string());
    Ok(())
}

就差一个serde_json_to_xml.