java - Is there any way to convert a Map to a JSON representation using Jackson without writing to a file? -

i'm trying use jackson convert hashmap json representation.

however, ways i've seen involve writing file , reading back, seems inefficient. wondering if there anyway directly?

here's example of instance i'd it

public static party readoneparty(string partyname) {   party localparty = new party();   if(connection==null) {     connection = new dbconnection();   } try {     string query = "select * pureservlet party_name=?";     ps = con.preparestatement(query);     ps.setstring(1, partyname);     resultset = ps.executequery();     meta = resultset.getmetadata();     string columnname, value;     resultset.next();     for(int j=1;j<=meta.getcolumncount();j++) { // necessary start @ j=1 because of mysql index starting @ 1       columnname = meta.getcolumnlabel(j);       value = resultset.getstring(columnname);       localparty.getpartyinfo().put(columnname, value); // hashmap within party keeps track of individual values. column name = label, value value     }   } }  public class party {    hashmap <string,string> partyinfo = new hashmap<string,string>();    public hashmap<string,string> getpartyinfo() throws exception {     return partyinfo;   } } 

the output this

"partyinfo": {   "party_name": "vsn",   "party_id": "92716518",   "party_number": "92716518" } 

so far every example i've come across of using objectmapper involves writing file , reading back.

is there jackson version of java's hashmap or map that'll work in similar way have implemented?

pass map objectmapper.writevalueasstring(object value)

it's more efficient using stringwriter, according docs:

method can used serialize java value string. functionally equivalent calling writevalue(writer,object) stringwriter , constructing string, more efficient.

example

import org.codehaus.jackson.map.objectmapper; import java.io.ioexception; import java.util.hashmap; import java.util.map;  public class example {      public static void main(string[] args) throws ioexception {         map<string,string> map = new hashmap<>();         map.put("key1","value1");         map.put("key2","value2");          string mapasjson = new objectmapper().writevalueasstring(map);         system.out.println(mapasjson);     } }