在excel文件中导出Jtable

Question

嗨我是java编程的新手，但这里是我的问题我正在设计GUI进行一些计算，需要在J表中显示输入和输出然后将它们导出到excel文件

代码工作就像魅力，但当我打开excel文件时，我发现它是空的..

j表

import java.awt.Desktop;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import javax.swing.JFileChooser;


public class Export extends javax.swing.JFrame {


public Export() {
    initComponents();
}


@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jScrollPane1 = new javax.swing.JScrollPane();
    jTable1 = new javax.swing.JTable();
    jButton1 = new javax.swing.JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jTable1.setModel(new javax.swing.table.DefaultTableModel(
        new Object [][] {
            {"Channel Model", global.channel_model, global.channel_model},                    
    {"System Bandwidth (MHz)", global.band_width_index,      global.band_width_index},
            {"Cell Edge Rate (Kbps)", global.Rreq_UL, global.Rreq_DL},
            {"Cell edge MCS", global.mcs, global.mcs},
    {"Antenna Configuration", global.DL_antenna_config, global.DL_antenna_config},
            {"Total RB Number", global.number_of_RB, global.number_of_RB},

            {"Tx", "", null},
            {"Max Power (dBm)", global.UE_Tx_power, global.UE_Tx_power},
            {"Cable Loss (dB)", global.cable_loss, global.cable_loss},
            {"Body Loss (dB)", global.body_loss, global.body_loss},
            {"Antenna Gain (dB)", global.UE_antennaGain, global.UE_antennaGain},
            {"EIRB (dB)", "", null},
            {"Rx", null, null},
            {"Antenna Gain (dB)", global.UE_antennaGain, global.UE_antennaGain},
            {"Cable Loss (dB)", global.cable_loss, global.cable_loss},
            {"Body Loss (dB)", global.body_loss, global.body_loss},
            {"Noise Figure (dB)", global.UE_noiseFigure, global.UE_noiseFigure},
            {"Thermal Noise (dB)", null, null},
            {"Interference Margin (dB)", global.Biul, global.Bidl},
            {"SINR (dB)", global.SINR, global.DL_SINR},
            {"Reciver Sensitivty (dB)", "", null},
            {"MAPL", null, null},
            {"Diversity (dB)", global.Tx_diversity_gain, global.Tx_diversity_gain},

            {"Shadow Fading Margin (dB)", global.shadow_margin, global.shadow_margin},
            {"MAPL (dB)", null, null},
            {"Cell Radius (Km)", global.R, global.R},
            {"Area of Dimensioning (Km squar", global.site_area, global.site_area},
            {"Site Type", global.type_of_site, global.type_of_site},
            {"Number of Sites  Due to Coverage", "", null}
        },
        new String [] {
            "Summary", "Uplink", "Downlink"
        }
    ));
    jTable1.setName("Export");
    jScrollPane1.setViewportView(jTable1);
    jTable1.getAccessibleContext().setAccessibleName("\"Export\"");
    jTable1.getAccessibleContext().setAccessibleDescription("");

    jButton1.setText("Export");
    jButton1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton1ActionPerformed(evt);
        }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap(562, Short.MAX_VALUE)
            .addComponent(jButton1)
            .addContainerGap())
        .addComponent(jScrollPane1)
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 455, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jButton1)
            .addGap(0, 0, Short.MAX_VALUE))
    );

    pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
   try{
     JFileChooser fileChooser = new JFileChooser();
    int retval = fileChooser.showSaveDialog(jButton1);

    if (retval == JFileChooser.APPROVE_OPTION) {
        File file = fileChooser.getSelectedFile();
        if (file != null) {
            if (!file.getName().toLowerCase().endsWith(".xls")) {
                file = new File(file.getParentFile(), file.getName() + ".xls");



            }

            try {
                ExcelExporter exp=new ExcelExporter();
                exp.exportTable(jTable1, file);


                Desktop.getDesktop().open(file);
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();

            } catch (FileNotFoundException e) {
                e.printStackTrace();
                System.out.println("not found");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        }


   }catch(Exception e){
       System.out.println("shit");
   }

}                                        

    public static void main(String args[]) {
            try {
        for (javax.swing.UIManager.LookAndFeelInfo info :     javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(Export.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(Export.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(Export.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Export.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new Export().setVisible(true);
         }
    });
 }

 // Variables declaration - do not modify                     
 private javax.swing.JButton jButton1;
 private javax.swing.JScrollPane jScrollPane1;
 private javax.swing.JTable jTable1;
 // End of variables declaration                   
 }

excel生成器类

import java.io.*;
import javax.swing.table.TableModel;
import javax.swing.*;


public class ExcelExporter {
    ExcelExporter(){}
    public void exportTable(JTable jTable1,File file) throws IOException{
      TableModel model=jTable1.getModel();
      FileWriter out=new FileWriter(file);
      BufferedWriter bw=new BufferedWriter(out);
      for (int i=0;i<model.getColumnCount();i++){
        bw.write(model.getColumnName(i)+"\t");
      }
      bw.write("\n");
      for (int i=0;i<model.getRowCount();i++){
        for (int j=0;j<model.getColumnCount();j++){
          bw.write(model.getValueAt(i,j).toString()+"\t");
        }
        bw.write("\n");
      }
      bw.close();
   System.out.print("Write out to"+file);


}
}

Answer 1

正如所建议的那样，Apache POI是一个非常好的api，用于操作和创建Excel文档。 它是免费的开源，因此很容易使用。 如果您尝试一下，那么这里是您创建文件的一种方法：

private static void writeToExcell(JTable table, Path path) throws FileNotFoundException, IOException {
    new WorkbookFactory();
    Workbook wb = new XSSFWorkbook(); //Excell workbook
    Sheet sheet = wb.createSheet(); //WorkSheet
    Row row = sheet.createRow(2); //Row created at line 3
    TableModel model = table.getModel(); //Table model


    Row headerRow = sheet.createRow(0); //Create row at line 0
    for(int headings = 0; headings < model.getColumnCount(); headings++){ //For each column
        headerRow.createCell(headings).setCellValue(model.getColumnName(headings));//Write column name
    }

    for(int rows = 0; rows < model.getRowCount(); rows++){ //For each table row
        for(int cols = 0; cols < table.getColumnCount(); cols++){ //For each table column
            row.createCell(cols).setCellValue(model.getValueAt(rows, cols).toString()); //Write value
        }

        //Set the row to the next one in the sequence 
        row = sheet.createRow((rows + 3)); 
    }
    wb.write(new FileOutputStream(path.toString()));//Save the file     
}

另一种方法是学习Microsoft Excel文件规范，然后以这种方式手动创建Excel文件。 您目前正在做的是将表中的数据写入文件，但不是Excel应用程序可以理解的任何方式。

Answer 2

对于编写和操作Excel文件，请使用Apache POI http://poi.apache.org/

如果您想在不使用外部库的情况下自己创建Excel文件，请记住excel文件数据以XML电子表格的形式存储，因此您必须创建这样的文件

<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <Worksheet ss:Name="Sheet1">
  <Table ss:ExpandedColumnCount="2" ss:ExpandedRowCount="2" x:FullColumns="1" x:FullRows="1">
   <Row>
    <Cell><Data ss:Type="String">Name</Data></Cell>
    <Cell><Data ss:Type="String">Example</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value</Data></Cell>
    <Cell><Data ss:Type="Number">123</Data></Cell>
   </Row>
  </Table>
 </Worksheet>
</Workbook>

来源： http ： //en.wikipedia.org/wiki/Microsoft_Excel

Answer 3

您可以在不使用Apache POI的情况下解决此问题。 对我有用的是在excel导出器类中编写时删除String转换。

bw.write(model.getValueAt(i,j)+"\t");

看看这是否有效。 这是因为getValueAt（）函数返回一个转换为String时出现问题的对象。 让我知道。