BD xml

package xml;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;


public class BD {


    public String saca_bases(){
        Conexion conecta = new Conexion(null);
        Connection con= conecta.getConnection();
        Statement st;
        ResultSet tabla=null;
        String sql="show databases" ;
        String base=null;
        ArrayList<String> bases= new ArrayList();
        try{
            boolean existe=false;
            st=con.createStatement();
            tabla=st.executeQuery(sql);
            do{

                existe=false;
                while(tabla.next()){
                    System.out.println(tabla.getString(1));
                    bases.add(tabla.getString(1));

                }
                base=teclado.cadena("\n¿Que base de datos quieres importar?");
                for(int i=0;i<bases.size();i++){
                    if(base.equalsIgnoreCase(bases.get(i))){
                        existe=true;
                    }
                }
                if(!existe){
                    System.out.println("Esa base de datos no existe!!");
                }
            }while(!existe);
            //con.close();
            tabla.close();
            st.close();


        }catch(SQLException e){
            e.printStackTrace();
        }
        return base;
    }


    public String saca_tablas(String base){
        Conexion conecta = new Conexion(base);
        Connection con= conecta.getConnection();
        Statement st;
        ResultSet tabla=null;
        String sql="show FULL tables FROM " +base ;
        ArrayList<String> elementos = new ArrayList<String>();
        String tabla_clave=null;

        try{
            boolean existe=false;
            st=con.createStatement();
            tabla=st.executeQuery(sql);
            do{

                existe=false;

                while(tabla.next()){
                    System.out.println(tabla.getString(1));
                    elementos.add(tabla.getString(1));

                }
                tabla_clave=teclado.cadena("\n¿Que tabla de datos quieres importar?");
                for(int i=0;i<elementos.size();i++){
                    if(tabla_clave.equals(elementos.get(i))){
                        existe=true;
                        tabla_clave=elementos.get(i);
                    }
                }
                if(!existe){
                    System.out.println("Esa base de datos no existe!!");
                }
            }while(!existe);

        //con.close();
        tabla.close();
        st.close();
        }catch(SQLException e){
            e.printStackTrace();

        }

        return tabla_clave;
    }
    public boolean exporta_tabla(String base, String tabla){
        boolean correcto=true;

        try{

            Class.forName("com.mysql.jdbc.Driver");
            Connection link= DriverManager.getConnection("jdbc:mysql://localhost/"+base,"root","");
            Statement st=link.createStatement();
            ResultSet rssaca_tabla=st.executeQuery("SELECT * FROM "+tabla);

            ArrayList<String> elementos = new ArrayList<String>();

            File fichero = new File("C:\\Users\\MAX\\Desktop\\Pruebas_ficheros\\base.xml");
            BufferedWriter Fescribe=null;

            if(!fichero.exists()){
                fichero.createNewFile();
                Fescribe = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fichero,false), "utf-8"));
            }else{
                Fescribe = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fichero,false), "utf-8"));
            }

            Fescribe.write("<XML> \r\n");
            System.out.println("<XML> \r\n");

            while(rssaca_tabla.next()){
                elementos=exporta_elementos(tabla,base);

                Statement stescribe=link.createStatement();
                System.out.println(tabla);
                ResultSet rs2=stescribe.executeQuery("SELECT * FROM "+tabla+"");

                Fescribe = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fichero,true), "utf-8"));


                 System.out.println("   <"+tabla+"> \r");
                while(rs2.next()){
                     Fescribe.write("   <"+tabla+"> \r\n" );
                    for(int i =1; i<elementos.size();i++){
                        Fescribe.write("        <"+elementos.get(i)+">" +rs2.getString(i)+"</"+elementos.get(i)+"> \r\n ");
                        System.out.println("        <"+elementos.get(i)+">" +rs2.getString(i)+"</"+elementos.get(i)+"> \r\n ");
                    }
                    Fescribe.write("    </"+tabla+" > \r\n");
                }

                System.out.println("    </"+tabla+" > \r\n");

            rs2.close();
            stescribe.close();
            correcto=true;
            }

            Fescribe.write("</XML> \r\n");
            System.out.println("</XML> \r\n");

        //link.close();
        rssaca_tabla.close();
        st.close();
        Fescribe.close();

        }catch (IOException | ClassNotFoundException | SQLException e){

            e.printStackTrace();
            correcto=false;
        }

        return correcto;
    }

    public ArrayList<String> exporta_elementos(String tabla,String base){
        ArrayList<String> elementos = new ArrayList<String>();


        try{
            Conexion conectaexporta_elementos = new Conexion(base);
            Connection con1= conectaexporta_elementos.getConnection();
            Statement st1;
            ResultSet rsexporta_elementos=null;
            String sql="describe " +tabla ;

            st1=con1.createStatement();
            rsexporta_elementos=st1.executeQuery(sql);

            while(rsexporta_elementos.next()){
                elementos.add(rsexporta_elementos.getString(1));
                System.out.println(rsexporta_elementos.getString(1));
            }

        //con1.close();
        rsexporta_elementos.close();
        st1.close();
        }catch(SQLException e){
            e.printStackTrace();
        }
        return elementos;
    }
}