Speichern JTable als text-Datei

Einem minimal-Beispiel, das ich gemacht, ist unten angegeben. Ich gibt die folgende form der Ausgabe:

Vorname: Kathy

Nachname: Smith

Sport: Snowboarden

Anzahl der Jahre: 5

Vorname: John

Nachname: Doe

Sport: Rudern

Anzahl der Jahre: 2

        String[] columnNames = {"First Name", "Last Name","Sport","# of Years"};

    Object[][] data = {
            {"Kathy", "Smith", "Snowboarding", "5"},
            {"John", "Doe", "Rowing", "2"},
            {"Sue", "Black", "Knitting", "8"},
            {"Jane", "White", "Speed reading", "10"},
            {"Joe", "Brown", "Pool", "20"}
    };

    JTable table = new JTable(data, columnNames);

    for(int row = 0; row < table.getRowCount(); row++) {

        for(int column = 0; column < table.getColumnCount(); column++) {
            System.out.print(table.getColumnName(column) + ": ");
            System.out.println(table.getValueAt(row, column));
        }
        System.out.println(""); //Add line space
    }

InformationsquelleAutor Snorre

Zusätzlich zu den Antworten bereits vorgesehen, ich habe implementiert eine Lösung, die speichert den Inhalt in eine text-Datei des Typs .csv (Komma-Getrennte Werte).

• Erstens, habe ich eine Methode, die den Inhalt einer JTable in ein zwei-dimensionales array vom Typ Object. Ich wählte den Typ Object, weil Sie verschiedene Spalten in einer JTable speichern kann verschiedene Arten von Daten, z.B. zahlen, Strings etc. Diese Methode befindet sich innerhalb meiner GUI front-end:

         /**
          *
          * This method extrapolates the data from the JTable and places 
          * it into a two-dimensional object array. <p>
          * 
          * It then returns the object array in preparation for writing 
            to disk
          *
          * 
          * @param  aTable - the selected table for rendering into a two-
  
             dimensional object array
          *
          * @return Object[][] - the two-dimensional object array which 
  
             shall be written to disk
          * 
          * @see 
          *
          */
          public Object[][] getTableData(JTable aTable)
          {
  
            int rowCount = aTable.getModel().getRowCount();
            int columnCount = aTable.getModel().getColumnCount();
  
            Object[][] curTableData = 
  
                 new Object[rowCount][columnCount];
  
            for ( int row = 0; row < rowCount; row++)
            {
              for (int column = 0; column < columnCount; column++)
              {
  
                curTableData[row][column]  = 
                     aTable.getModel().getValueAt(row,column);
  
       //        System.out.println("curTableData["+row+"]["+column+"] = "+curTableData[row][column]);
  
              }
            }
  
            return curTableData;
  
          }

• Zweitens habe ich eine Klasse angelegt, die verantwortlich für das schreiben der Inhalt der zwei-dimensionalen object-array (JTable Inhalt) auf die Festplatte. Diese ist im folgenden beschrieben:

  import java.io.*;
  
  /**
  *
  * This class is responsible for writing the 2D object to disk.
  * The 2d Object contains your JTable contents 
  * <p>
  *
  * @author      Mark Burleigh
  * @version     %I%, %G%
  * @since       1.0
  *
  */
  public class WriteJTableContents
  {
  /**
   *
   * This constructor takes in two parameters. It is also responsible
   * for writing the JTable contents to disk (to csv file)
   * 
   * 
   * @param  aData - the JTable data to be saved to disk
   * @param  afile  - the name of the file where the data shall be saved
   * (this is a .CSV type file)
   *
   *
   */
    public WriteRandomSampleData(Object[][] aData, String afile)
    {
          writeToDisk(aData,afile);
  
    //This method prints the two-dimensional array to the command console
    // printData();
  
    }
  
    /**
    *
    * This method is responsible for writing the contents of a JTable (2d 
    * array object) to disk (csv text file)
    * <p>
    * 
    * @param  aData - the 2D data (Jtable contents) to be stored to disk
    * @param  aDatafile - the file where the data shall be stored
    * to disk. This shall be of type.CSV
    *
    * @return 
    * 
    * @see 
    *
    */
    public void writeToDisk(Object[][] aData, String aDatafile)
    {
  
      try
       {
  
          FileOutputStream fout =  new FileOutputStream(aDatafile, false);
  
          BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fout));
  
          //Headers
          bw.append("Script No., Candidate No., Mark, Grade,Script No., Candidate No., Mark, Grade");
          //End of data row (Jable row) so append new line character in csv file
          bw.append('\n');
  
          for (int row = 0; row < aData.length; row++)
          {
  
            for (int column = 0; column < aData[row].length; column++)
            {
  
              if(aData[row][column] == null)
              {
                bw.append("null");
                //The comma separated value
                bw.append(',');
              }
              else
              {
                /* In my particular example, I am doing some checking on 
  
                    the 2d array for types: 
                    if the data is not of type null (as checked above)
                    then it must be of type Integer.
                    This is because the 2D data array only contains data of either
                    Integer or null
  
                    each of these object types have a method called toString().
                    we need this in order to convert the types to a string prior to wrting them to
                    the file.
  
                */
                bw.append(aData[row][column].toString());
                bw.append(',');
              }
  
            }//end column loop (inner loop)
  
            bw.append('\n');
  
          }//end row loop (outer loop)
  
          bw.close();
  
      }
      catch (Exception e)
      {
  
          e.getStackTrace();
      }
  
    }//end of readFileFromDisk
  
    /**
    *
    * These methods is responsible for printing the random sample scripts
    * Into the command console.
    * <p>
    * 
    *
    */
    public void printData()
    {
        //System.out.println();
        //System.out.println("=======WriteRandomSampleData Class===========");
        //System.out.println();
  
        for (int row = 0; row < data.length; row++)
        {
          for (int column = 0; column < data[row].length; column++)
          {
              System.out.println("data["+row+"]["+column+"] = " +data[row][column]);
          }
        }
  
    }
  
  //==================Instance Variables=============================
    //JTable contents hedata
    private Object[][] data;
  
   //====================Test Driver============================
  
    public static void main(String args[])
    {
     //file seperator for windows platform '\\'
      String aFileLocation = "C:\\dirA\\subdir1\\subdir2\\";
  
      //Dummy values - 2D array which stores the contents of a 
      //JTable into a csv text file
       Object[][] testData = new Object [][] {
  
                      {new Integer(1),new Integer(1),null,null,new Integer(11),new Integer(1),null,null},
                      {new Integer(2),new Integer(1),null,null,new Integer(12),new Integer(1),null,null},
                      {new Integer(3),new Integer(1),null,null,new Integer(13),new Integer(1),null,null},
                      {new Integer(4),new Integer(1),null,null,new Integer(14),new Integer(1),null,null},
                      {new Integer(5),new Integer(1),null,null,new Integer(15),new Integer(1),null,null},
                      {new Integer(6),new Integer(1),null,null,new Integer(16),new Integer(1),null,null},
                      {new Integer(7),new Integer(1),null,null,new Integer(17),new Integer(1),null,null},
                      {new Integer(8),new Integer(1),null,null,new Integer(18),new Integer(1),null,null},
                      {new Integer(9),new Integer(1),null,null,new Integer(19),new Integer(1),null,null},
                      {new Integer(10),new Integer(1),null,null,new Integer(20),new Integer(1),null,null}
  
                       };
  //SampleData_TEST.csv gets created in the particular directory
  //and the file gets populated with the contents of the JTable
                       new WriteRandomSampleData(testData,aFileLocation2+"SampleData_TEST.csv");
  
  
    }
  }

Den Inhalt der resultierenden SampleData_TEST.csv-Datei werden im folgenden beschrieben:

Wie oben dargestellt, wird das csv-Dateiformat kann in Microsoft Excel geöffnet werden kann vielseitiger sein (je nach Art der Daten) als eine .doc-oder .txt-Datei

InformationsquelleAutor Mark Burleigh