How to convert es dsl query to string

[vincentchen007]

Description

Hell team, I need to upgrade my ES version from 7.17 to 8.13.
In version 7, I can use to_string to convert an es dsl query to a string type.
However, I cannot find any similar method in ES java 8.
Could you please help me?
Thank you!

[charles260]

Description

ByteArrayOutputStream baos = new ByteArrayOutputStream();
JsonGenerator generator = transport.jsonpMapper().jsonProvider().createGenerator(baos);
searchRequest.serialize(generator, transport.jsonpMapper());
generator.close();
System.out.println(baos);