如何减少列的宽度并在所需坐标处将JTable定位在Java中

Question

i am having problem with JTable. need your help

• i want to reduce size of every column (size should be same for all) so that it can be saved in pdf completely because currently it is occupying full frame and is not being saved fully in pdf.

below is snapshot of frame and pdf of the frame

• i want to place the table in center like in the below image(suppose green border is JFrame). currently it is at top of the frame.

here is my code

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.sql.*;
import java.util.*;
import javax.swing.table.*;
import javax.swing.border.*;
import com.lowagie.text.Document;
import com.lowagie.text.PageSize;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfWriter;
import java.io.FileOutputStream;
import java.awt.Graphics2D;
import javax.swing.table.TableColumn;



class tt_show extends JFrame implements ItemListener,ActionListener
{

JLabel l1,l2;

Choice c1,c2,c3;

JButton b1;

Checkbox cb1,cb2;

CheckboxGroup cbg;

Container c=this.getContentPane();

Graphics g;



tt_show()
{

    setLayout(null);

    l1=new JLabel("Course");

    l2=new JLabel("Semester");

    b1=new JButton("OK");

    cbg=new CheckboxGroup();

    cb1 = new Checkbox("full",cbg,false);

    cb2 = new Checkbox("specific day",cbg,false);

    c1 = new Choice();

    c2 = new Choice();

    c3 = new Choice();

    c3.add("Monday"); c3.add("Tuesday"); c3.add("Wednesday");       c3.add("Thursday"); c3.add("Friday");

    c1.add("MCA");

    c.add(l1); c.add(l2); c.add(b1); c.add(l1); c.add(cb1); c.add(cb2);   c.add(c1); c.add(c2); //c.add(c3);

    l1.setBounds(500,160,100,100);
    c1.setBounds(700,200,100,100);

    l2.setBounds(500,260,100,100);
    c2.setBounds(700,300,100,100);

    cb1.setBounds(500,350,200,100);
    cb2.setBounds(700,350,200,100);

    b1.setBounds(600,500,100,30);

    b1.addActionListener(this);
    c1.addItemListener(this);




    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public void itemStateChanged(ItemEvent ie)
{

    if(ie.getSource()==c1)
    {
        for(int i=0;i<5;i++)
        {
            c2.add(String.valueOf(i+1));
        }
    }
}

public void actionPerformed(ActionEvent ae)
{
    String str1="",str2="",str3="",str4="";

    str1=c1.getSelectedItem();

    str2=c2.getSelectedItem();

    str3=cbg.getSelectedCheckbox().getLabel();

    str4="select * from ";

    int count=0;

    Vector<Vector> data = new Vector<Vector>();

    Vector<String> row = new Vector<String>();

    Vector<String> cols = new Vector<String>();

    cols.add("Day  / Lecture  -->>");   cols.add("First");       cols.add("Second");  cols.add("Third");   cols.add("Fourth");  cols.add("Fifth");

    cols.add("Sixth");   cols.add("Seventh");  cols.add("Eighth");






    str4=str4+str1+str2;

    try
            {
                DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());


                Connection con =   DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","hr","hr");


                Statement stmt = con.createStatement();


                ResultSet rs = stmt.executeQuery(str4);


                while(rs.next())
                {
                        count++;

                        switch(count)
                        {
                            case 1 : row.add("Monday");
                                 //row=new Vector<String>();
                                 break;

                            case 2 : row.add("Tuesday");
                                // row=new Vector<String>();
                                 break;

                            case 3 : row.add("Wednesday");
                                 //row=new Vector<String>();
                                 break;

                            case 4 : row.add("Thursday");
                                // row=new Vector<String>();
                                 break;

                            case 5 : row.add("Friday");
                                 //row=new Vector<String>();
                                 break;
                        }


                        for(int i=1;i<=8;i++)
                        {
                            row.add(rs.getString(i));
                        }
                        data.add(row);
                        row=new Vector<String>();
                }



            }
            catch(Exception e)
            {
                //System.out.println(e.printStackTrace());
            }


            time_table ob1 =new time_table();

            ob1.setTitle("TIME TABLE ->> "+str1+"-"+str2);

            ob1.setExtendedState(JFrame.MAXIMIZED_BOTH);

            ob1.show(data,cols,str1,str2);

            ob1.setVisible(true);
















}

public static void main(String args[]) throws Exception
{

    tt_show obj = new tt_show();

    obj.setExtendedState(JFrame.MAXIMIZED_BOTH);

    obj.setTitle("TIME TABLE");

    obj.setVisible(true);
}

}


class time_table extends JFrame implements ActionListener
{

String course,sem;

JTable tab;





time_table()
{
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JButton b1 = new JButton("Save As PDF");

    Container c=getContentPane();

    c.add(b1);



    b1.setBounds(700,700,200,30);

    b1.addActionListener(this);



}

public void show(Vector<Vector> data1,Vector<String> cols1,String s1,String s2)
{


    course=s1;

    sem=s2+".pdf";

    tab = new JTable(data1,cols1);

    TableColumn column = null;

    for(int i=1;i<=8;i++)
    {
        column = tab.getColumnModel().getColumn(i);

             column.setPreferredWidth(5);
        }


    tab.setEnabled(false);

    tab.setBorder(BorderFactory.createLineBorder(Color.green,3));

    tab.setFont(new Font("Arial",Font.PLAIN,15));

    tab.setRowHeight(30);

    tab.setGridColor(Color.red);

    JTableHeader head = tab.getTableHeader();

    head.setFont(new Font("SansSerif", Font.ITALIC, 15));

    head.setForeground(Color.magenta);

    Container c = this.getContentPane();

    c.setLayout(new BorderLayout());



    c.add("North",head);



    c.add("Center",tab);





    DefaultTableCellRenderer centerRenderer = new DefaultTableCellRenderer();

    centerRenderer.setHorizontalAlignment( SwingConstants.CENTER );

    tab.setDefaultRenderer(String.class, centerRenderer);
}

 private void print() {
Document document = new Document(PageSize.A4.rotate());
try {


  PdfWriter writer = PdfWriter.getInstance(document, new    FileOutputStream(course+sem));

  document.open();
  PdfContentByte cb = writer.getDirectContent();

  cb.saveState();
  Graphics2D g2 = cb.createGraphicsShapes(1600, 500);

  Shape oldClip = g2.getClip();
  g2.clipRect(0, 0, 1600, 1000);

  tab.print(g2);
  g2.setClip(oldClip);

  g2.dispose();
  cb.restoreState();
} catch (Exception e) {
  System.err.println(e.getMessage());
}
document.close();
}

    public void actionPerformed(ActionEvent ae)

    {

        print();    
    }
}

Answer 1

i want to reduce size of every column (size should be same for all)

After creating the table and setting the model you do something like:

JTable table = new JTable(...);
TableColumnModel tcm = table.getColumnModel();

for (int i = 0; i < tcm.getColumnCount(); i++) 
{
    tcm.getColumn(i).setPreferredWidth(...);
}

Another option might be to use the Table Column Adjuster . This class will set the size of the column based on the data in the column. So it will ensure that all the data is visible.

Answer 2

So this is some test code, which makes use the JTable 's Printable implementation to print the table. This is normally used to print the table to a printer, but you can fake the process

import com.itextpdf.text.Document;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.print.PageFormat;
import java.awt.print.Paper;
import java.awt.print.Printable;
import java.io.FileOutputStream;
import java.util.Arrays;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JTable;
import javax.swing.SwingConstants;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.JTableHeader;

public class TestPDF {

    public static void main(String[] args) {

        Vector columnNames = new Vector();
        columnNames.add("Day  / Lecture  -->>");
        columnNames.add("First");
        columnNames.add("Second");
        columnNames.add("Third");
        columnNames.add("Fourth");
        columnNames.add("Fifth");

        columnNames.add("Sixth");
        columnNames.add("Seventh");
        columnNames.add("Eighth");

        Vector data = new Vector();
        data.add(makeRow(new String[]{"Monday", "LAB", "", "", "", "CS rashmi", "STOA", "STOA", ".NET"}));
        data.add(makeRow(new String[]{"Tuesday", ".NET", ".NET", "SC", "SC", "ADBMS", "ADBMS", "CS", "STOA"}));
        data.add(makeRow(new String[]{"Wednesday", "ADBMS", "ADBMS", "SC", "SC", ".NET", "CS", "CS", "STOA"}));
        data.add(makeRow(new String[]{"Thursday", "LAB .Net", "", "", "", "ADBMS P", ".NET", "CS", "STOA"}));
        data.add(makeRow(new String[]{"Friday", "LAV ADBMS", "", "", "", "LAB .NET", "", "", ""}));

        JTable tab = new JTable(data, columnNames);

//        for (int i = 1; i <= 8; i++) {
//            TableColumn column = tab.getColumnModel().getColumn(i);
//            column.setPreferredWidth(5);
//        }
//
//        tab.setEnabled(false);
//
        tab.setBorder(BorderFactory.createLineBorder(Color.green, 3));
        tab.setFont(new Font("Arial", Font.PLAIN, 15));
        tab.setRowHeight(30);
        tab.setGridColor(Color.red);

        JTableHeader head = tab.getTableHeader();
        head.setFont(new Font("SansSerif", Font.ITALIC, 15));
        head.setForeground(Color.magenta);

        DefaultTableCellRenderer centerRenderer = new DefaultTableCellRenderer();
        centerRenderer.setHorizontalAlignment(SwingConstants.CENTER);
        tab.setDefaultRenderer(String.class, centerRenderer);

//        JFrame frame = new JFrame();
//        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
//        frame.add(new JScrollPane(tab));
//        frame.pack();
//        frame.setLocationRelativeTo(null);
//        frame.setVisible(true);
//        JOptionPane.showMessageDialog(null, new JScrollPane(tab));
        Document document = new Document(PageSize.A4.rotate());
        try {

            PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("Test.pdf"));

            document.open();
            PdfContentByte cb = writer.getDirectContent();

            cb.saveState();
            Graphics2D g2 = cb.createGraphicsShapes(1600, 500);

            Shape oldClip = g2.getClip();
            g2.clipRect(0, 0, 1600, 1000);

            Rectangle pageSize = document.getPageSize();
            float width = pageSize.getWidth();
            float height = pageSize.getHeight();

            // Size the JTable to be the width of the page, but maintain
            // it's own overall height
            tab.setSize((int) width, tab.getPreferredSize().height);

            JTableHeader tableHeader = tab.getTableHeader();
            tableHeader.setSize((int) width, tableHeader.getPreferredSize().height);

            // Get the table's printable
            Printable printable = tab.getPrintable(JTable.PrintMode.FIT_WIDTH, null, null);

            // Create a Paper which meets the size of the available document...
            Paper paper = new Paper();
            paper.setSize(height, width);
            paper.setImageableArea(0, 0, height, width);
            // Create a PageFormat for the Paper
            PageFormat pageFormat = new PageFormat();
            pageFormat.setOrientation(PageFormat.LANDSCAPE);
            pageFormat.setPaper(paper);
            // Print each page of the table
            int pageIndex = 0;
            while (printable.print(g2, pageFormat, pageIndex) != Printable.NO_SUCH_PAGE) {
                System.out.println("Print " + pageIndex);
                printable.print(g2, pageFormat, pageIndex);
                pageIndex++;
            }
            g2.setClip(oldClip);

            g2.dispose();
            cb.restoreState();
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }
        document.close();
    }

    protected static Vector makeRow(String[] values) {
        return new Vector(Arrays.asList(values));
    }

}

You may need to play around with iText a bit if you want to decrease the size of the margins