java - 如何减少列的宽度并将java中的JTable定位在所需的坐标处

Question

我在使用 JTable 时遇到问题。需要你的帮助

• 我想减小每列的大小(所有列的大小应该相同)，以便它可以完全保存在 pdf 中，因为目前它占据全帧并且没有完全保存在 pdf 中。

下面是框架的快照和框架的 pdf

• 我想将表格放在中心，如下图所示(假设绿色边框是 JFrame)。目前它位于框架的顶部。

这是我的代码

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)

创建表格并设置模型后，您可以执行以下操作:

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

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

另一个选择可能是使用 Table Column Adjuster 。此类将根据列中的数据设置列的大小。这样就保证了所有的数据都是可见的。