DROP TABLE xml_docs;
CREATE TABLE xml_docs(
id serial PRIMARY KEY,
cad_number character(50),
gkuzu_name character(50),
gkuzu xml,
rreq_name character(50),
rreq xml
)

String sql = "INSERT INTO xml_docs(cad_number,gkuzu_name,gkuzu,rreq_name,rreq) VALUES(?,?,?,?,?)";
  PreparedStatement stmt = ce.prepareStatement(sql);
  stmt.setString(1, "11:33:5464563");
  stmt.setString(2, xml_gkuzu.getName());
  stmt.setString(3, xml_gkuzu.toString());
  stmt.setString(4, xml_rreq.getName());
  stmt.setString(5, xml_rreq.toString());
  stmt.executeQuery();
ce.close();
  se.close();

Exception in thread "main" org.postgresql.util.PSQLException: ERROR: column "gkuzu" is of type xml but expression is of type character varying
Подсказка: You will need to rewrite or cast the expression.

String sql1 = "INSERT INTO xml_docs(cad_number,gkuzu_name,gkuzu,rreq_name,rreq) VALUES(11335464563,"+xml_gkuzu.getName()+",XMLPARSE("+xml_gkuzu.toString()+"),"+xml_rreq.getName()+",XMLPARSE("+xml_rreq.toString()+"))";

Exception in thread "main" org.postgresql.util.PSQLException: ERROR: syntax error at or near "bf48e000b0"

INSERT INTO xml_docs(id, gkuzu) VALUES (1, XMLPARSE('<foo><bar>Hello</bar></foo>'));

String sql = "INSERT INTO xml_docs(id, gkuzu) VALUES (?, XMLPARSE(?))";
[...]
stmt.setString(2, "<foo>Hello World!</foo>");

INSERT INTO xml_docs(id, gkuzu) VALUES (1, XMLPARSE('<foo>Hello World!</foo>'));

String xml = xml_gkuzu.toString();

SQLXML sqlxml = connection.createSQLXML();
sqlxml.setString(xml);
stmt.setSQLXML(3, sqlxml);

jdbc:postgresql://localhost/test?stringtype=unspecified
or
jdbc:postgresql://localhost/test?user=user&password=pass&stringtype=unspecified

String sql = "INSERT INTO xml_docs(id, gkuzu) VALUES (?, XML(?))";
[...]
stmt.setString(2, "<foo>Hello World!</foo>");

INSERT INTO xml_docs(id, gkuzu) VALUES (1, XML('<foo>Hello World!</foo>'));