Java JTable Hide / Off Table Column Header

jTable_sales_cotation.setTableHeader(null);

java JTable resize Table Column

 try {
           
      
            //get table model
            DefaultTableModel model = (DefaultTableModel) jTable_sales_cotation.getModel();
            model.addRow(new Object[]{
                item_code, item_description, quantity, unit, price,
                discount, line_total });
               jTable_sales_cotation.setAutoResizeMode(jTable_sales_cotation.AUTO_RESIZE_OFF);
              jTable_sales_cotation.getColumnModel().getColumn(0).setPreferredWidth(70);
              jTable_sales_cotation.getColumnModel().getColumn(1).setPreferredWidth(270);
              jTable_sales_cotation.getColumnModel().getColumn(2).setPreferredWidth(50);
              jTable_sales_cotation.getColumnModel().getColumn(3).setPreferredWidth(52);
              jTable_sales_cotation.getColumnModel().getColumn(4).setPreferredWidth(110);
              jTable_sales_cotation.getColumnModel().getColumn(5).setPreferredWidth(78);
              jTable_sales_cotation.getColumnModel().getColumn(6).setPreferredWidth(90);
   
            //DB operation

            //log.main(query);
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Error: " + e, "Error in connectivity", JOptionPane.ERROR_MESSAGE);
        }
        update_total();
//        __Update_table();
//        __clear();

java Multiple DB Table Insert Statement and Rollback

  try {
                                    //DB OPERATION
                                    //TURN OFF AUTO COMMIT
                                    conn.setAutoCommit(false);
                                    //CREATE DB SAVEPOINT
                                    Savepoint save1 = conn.setSavepoint();
           
                              try{
                             
                          
                                        java.sql.Statement pst = conn.createStatement();
                                        pst.executeUpdate("INSERT INTO sales_dcl_orders ("
                                        + "order_no, trans_type, version, type,"
                                        + "debtor_no, branch_code, reference, customer_ref,"
                                        + "comments, ord_date, order_type, ship_via,"
                                        + "delivery_address, contact_phone, contact_email, deliver_to,"
                                        + "freight_cost, from_stk_loc, delivery_date, payment_terms,"
                                        + "total, insert_date,user_name) VALUES "
                                        + "('"+ max_id + "','"  + 32+ "','"  + 0 + "','"  + 0 + "'"
                                        + ",'"  + cus_id + "','"  + branch_id + "','"  + reference + "','"  + customer_ref + "'"
                                        + ",'"  + comments + "','"  + Ord_Date + "','"  + Order_Type_id + "','"  + Ship_Vaia_Id + "'"
                                        + ",'"  + Delv_Address + "','"  + Phone + "','"  + "" + "','"  + deliver_to + "'"
                                        + ",'"  + shipping_charge + "','"  + From_Loc_Id + "','"  + val_date + "','"  + Payment_tarm_id + "'"
                                        + ",'"  + inv_total + "','"  + u.todays_datetime() + "','"  + Dashboard.user_id + "')",Statement.RETURN_GENERATED_KEYS);
                
                               
                                   pst.executeUpdate("INSERT INTO audit_trail ("
                                        + "type, trans_no, user_id, description,"
                                        + "fiscal_year, gl_date, type_details ) VALUES "
                                        + "('"+ 32 + "','"  + max_id + "','"  + Dashboard.user_id  + "','"  + "" + "'"
                                        + ",'"  + fiscal_year_id + "','"  + u.todays_date() + "','"  + "Sales Quotation" + "')",Statement.RETURN_GENERATED_KEYS);
                             
                                  
                                 
                                  // get details from table and send to DB
                                 
                                int rowcount = jTable_sales_cotation.getRowCount();
                                   String item_code;
                                   String item_desc;
                                   String item_unit;
                                   String item_quentity;
                                   String item_price;
                                   String item_discount;
                                   while(rowcount > 0){
                                    rowcount--;
                                    item_code = jTable_sales_cotation.getModel().getValueAt(rowcount, 0).toString();
                                    item_desc = jTable_sales_cotation.getModel().getValueAt(rowcount, 1).toString();
                                    item_quentity = jTable_sales_cotation.getModel().getValueAt(rowcount, 2).toString();
                                    item_unit = jTable_sales_cotation.getModel().getValueAt(rowcount, 3).toString();
                                    item_price = jTable_sales_cotation.getModel().getValueAt(rowcount, 4).toString();
                                    item_discount = jTable_sales_cotation.getModel().getValueAt(rowcount, 5).toString();

                                      pst.executeUpdate("INSERT INTO sales_dcl_order_details ("
                                        + "order_no, trans_type, stk_code, description, unit,"
                                        + "unit_price, quantity, discount_percent, insert_date ) VALUES "
                                        + "('"+ max_id + "','"  + 32+ "','"  + item_code + "','"  + item_desc + "','"  + item_unit + "'"
                                        + ",'"  + item_price + "','"  + item_quentity + "','"  + item_discount + "','"  + u.todays_datetime() + "')",Statement.RETURN_GENERATED_KEYS);
                                     
                                }
                        //ALL DONE, COMMIT DB CHANGES
                                       conn.commit();
                                       JOptionPane.showMessageDialog(this, "Successful", "Successful", JOptionPane.PLAIN_MESSAGE);
                            } catch (Exception e) {
                                        pst.close();
                                        conn.rollback(save1);
                                        conn.setAutoCommit(true);
                                        JOptionPane.showMessageDialog(this, "Failed 3" +e, "Error in connectivity", JOptionPane.ERROR_MESSAGE);
                                        return;
                            }
                    } catch (Exception e) {
                        JOptionPane.showMessageDialog(this, e, "Invalid", JOptionPane.ERROR_MESSAGE);
                    }
            
                //TURN ON AUTO COMMIT
                       try {
                           conn.setAutoCommit(true);
                       } catch (SQLException ex) {
               //            Logger.getLogger(PurchaseOrder.class.getName()).log(Level.SEVERE, null, ex);
                       }
                    }

Java Hash Map Set and get Data

Set Hash Map

 private TreeMap <String, String> itemMap = new TreeMap<String, String>();
     private TreeMap <String, String> itemMap1 = new TreeMap<String, String>();
     private void FillCombo_Items(){
       
         //int row = jTable_Roles.getSelectedRow();
          // jCombo_Items.removeAllItems();
           itemMap.clear();
           itemMap1.clear();
          
           String S;
           String sql = "Select stock_id,description,units from inventory_dcl_stock_master ORDER BY description ASC";
        try {
                pst = conn.prepareStatement(sql);
               ResultSet rs_item = pst.executeQuery();
                jCombo_Items.addItem("");
                  
        while(rs_item.next()){
                 S = rs_item.getString("description");
                jCombo_Items.addItem(S);
                itemMap.put(rs_item.getString("stock_id"), S);
                itemMap1.put(S, rs_item.getString("units"));
              }
             
        }catch (Exception e) {
           
            JOptionPane.showMessageDialog(this, "Error in connecitivity " +e);
        }
       
        
    }

Get Data From  it

  stock_name = (String) jCombo_Items.getSelectedItem();
           stock_id = getKeyForValue(stock_name,itemMap);
           unit = getValueForKey(stock_name,itemMap1);
         

Java View Hashmap Data

Download Gson

https://code.google.com/p/google-gson/

Gson gson = new Gson();

System.out.println(gson.toJson(itemMap1));

Output:
{"17inch VGA Monitor":"ea","32MB VGA Card":"ea","52x CD Drive":"ea","Assembly Labour":"hrs","Black Fluid":"ea","Blue Fluid":"ea","Fluid 2":"ea","MK-Comx":"ea","P4 Business System":"ea","RX-35V":"ea","RX-55V":"ea","Red Fluid":"ea","s o d a":"ea"}

Java Xml modify

package Utility;

/**
 *
 * @author Sakib
 */
import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class ModifyXMLFile {

    public static void main(String argv[]) {

       try {
        String filepath = "c:\\temp\\file.xml";
        DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
        Document doc = docBuilder.parse(filepath);

        // Get the root element
        Node company = doc.getFirstChild();

        // Get the staff element , it may not working if tag has spaces, or
        // whatever weird characters in front...it's better to use
        // getElementsByTagName() to get it directly.
        // Node staff = company.getFirstChild();

        // Get the staff element by tag name directly
        Node staff = doc.getElementsByTagName("staff").item(1);

        // update staff attribute
        NamedNodeMap attr = staff.getAttributes();
        Node nodeAttr = attr.getNamedItem("id");
        nodeAttr.setTextContent("2");

        // append a new node to staff
        Element age = doc.createElement("age");
        age.appendChild(doc.createTextNode("28"));
        staff.appendChild(age);

        // loop the staff child node
        NodeList list = staff.getChildNodes();

        for (int i = 0; i < list.getLength(); i++) {

                   Node node = list.item(i);

           // get the salary element, and update the value
           if ("salary".equals(node.getNodeName())) {
            node.setTextContent("2000000");
           }

                   //remove firstname
        //   if ("firstname".equals(node.getNodeName())) {
        //    staff.removeChild(node);
        //   }

        }

        // write the content into xml file
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(new File(filepath));
        transformer.transform(source, result);

        System.out.println("Done");

       } catch (ParserConfigurationException pce) {
        pce.printStackTrace();
       } catch (TransformerException tfe) {
        tfe.printStackTrace();
       } catch (IOException ioe) {
        ioe.printStackTrace();
       } catch (SAXException sae) {
        sae.printStackTrace();
       }
    }
}

Java XML Read

package Utility;

/**
 *
 * @author Sakib
 */


import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class ReadXMLFile {

   public static void main(String argv[]) {

    try {

    SAXParserFactory factory = SAXParserFactory.newInstance();
    SAXParser saxParser = factory.newSAXParser();

    DefaultHandler handler = new DefaultHandler() {

    boolean bfname = false;
    boolean blname = false;
    boolean bnname = false;
    boolean bsalary = false;

    public void startElement(String uri, String localName,String qName,
                Attributes attributes) throws SAXException {

        System.out.println("Start Element :" + qName);

        if (qName.equalsIgnoreCase("FIRSTNAME")) {
            bfname = true;
        }

        if (qName.equalsIgnoreCase("LASTNAME")) {
            blname = true;
        }

        if (qName.equalsIgnoreCase("NICKNAME")) {
            bnname = true;
        }

        if (qName.equalsIgnoreCase("SALARY")) {
            bsalary = true;
        }

    }

    public void endElement(String uri, String localName,
        String qName) throws SAXException {

        System.out.println("End Element :" + qName);

    }

    public void characters(char ch[], int start, int length) throws SAXException {

        if (bfname) {
            System.out.println("First Name : " + new String(ch, start, length));
            bfname = false;
        }

        if (blname) {
            System.out.println("Last Name : " + new String(ch, start, length));
            blname = false;
        }

        if (bnname) {
            System.out.println("Nick Name : " + new String(ch, start, length));
            bnname = false;
        }

        if (bsalary) {
            System.out.println("Salary : " + new String(ch, start, length));
            bsalary = false;
        }

    }

     };

       saxParser.parse("c:\\temp\\file.xml", handler);

     } catch (Exception e) {
       e.printStackTrace();
     }

   }

}