servlets - How to view what is inside database JDBC ResultSet in java -

i getting error saying string missing inside resultset returned database. have problem: how can see inside resultset?

examples available on google explicit methods getstring() or getint() thse methods suppose know looking for. need - elements available inside resultset.

something when issue resultset.tostring() command, , show me kind of map variable names - possible?

edit:

if useful - below piece of code:

public project maprow(resultset resultset, int i) throws sqlexception {         system.out.println(resultset.tostring());         return new project(resultset.getint("project_id"), resultset.getstring("project_name"),                             resultset.getstring("project_description"), new category(resultset.getint("category_id"),                                                                                     resultset.getstring("category_name")),                             resultset.getstring("project_link"), resultset.getstring("project_qa"));     } 

error:

caused by: org.postgresql.util.psqlexception: column name category_id not found in resultset. 

the resultset contains no element after execute statement. first row of information, need rs.next().

here simple iteration through resultset values.

boolean hasvalue = false; while(resultset.next()) {     hasvalue = true;     out.println(resultset.getstring("column_name");     out.println(resultset.getint("column_name"); } if(hasvalue)     out.println("result set has values inside of it"); else out.println("result set has no values inside of it"); 

as long have values inside resultset variable, need iterate next value. default, after query executed, have no value inside of because might have no value.

edit:

resultsetmetadata metadata = resultset.getmetadata(); int count = metadata.getcolumncount(); //number of column string columnname[] = new string[count];  (int = 1; <= count; i++) {    columnname[i-1] = metadata.getcolumnlabel(i));  } 

this gives column names, if want.