java - 当 jtable 中存在空值时，如何分隔要动态添加到 jtable 中的行数据？

Question

我的要求是在 JTable 中动态添加行和列。

我尝试了一个简单的代码，但我陷入了一个地方，当行数据中存在空值时，我不知道如何分隔。我尝试使用“\s+”分隔符分割行数据，但是当行数据中有空值时这不起作用。我的代码仅在行数据有值时才有效。

请在下面找到我的代码

<小时/>

String[] resultLines = data.split("\n", 0);

parsedResult = new String[resultLines.length][];
String cols[] = resultLines[1].split("\\s+");
String[] columnsParsed = new String[cols.length];
for (int i = 0; i < cols.length; i++) {
    String colName = cols[i];
    columnsParsed[i] = colName;
}
parsedResult[0] = columnsParsed;

int k = 1;
for (int j = 3; j < parsedResult.length; j++) {
    parsedResult[k] = resultLines[j].trim().split("\\s+");
    k++;
}

String[] columns = parsedResult[0];
String[][] data1 = new String[parsedResult.length - 1][];
for (int i = 1; i < parsedResult.length; i++) {
    data1[i - 1] = parsedResult[i];
}

DefaultTableModel model = new DefaultTableModel(data1, columns);
jTable1.setModel(model);

请引用以下数据

Handles   NPM(K)    PM(K)      WS(K)     CPU(s)   Id  SI  ProcessName                                                  
-------   ------    -----      -----     ------   --  -- -----------                                                  
    322      17     3308      13800              2572   0  armsvc                                                       
    171      10     6304      11224       0.11   3836   0  audiodg                                                      
    591      31    11864      42480       1.39   3660   9  backgroundTaskHost                                           
   1488      55    28736      61776              1892   0  CcmExec                                                      
     42       4     2332       3816       0.05  10720   9  cmd                                                          
     74       6     5704       4452       0.09  12032   9  cmd                                                          
     58       5     4312       6028       0.25  12188   9  cmd                                                          
     42       4     2324       3800       0.06  13760   9  cmd                                                          
    235      14     3004      10092              1896   0  CmRcService                                                  
    216      12     2520      13128             12980   0  CompatTelRunner                                              
     88       5      916       4060             14084   0  CompatTelRunner   

你们能帮我解决这个问题吗？

Answer 1

如果您利用数据右对齐(最后一列除外)的事实，则可以尝试下面我演示的方法，而不是“分隔符”方法。

由于数据对齐是精确的，因此我为每列获取精确的字符数。尝试一下，看看它是否适合您。

(我从您代码中的 resultLines 开始。)

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

public class ParseTableData {

  public static String[] parseRow(String line) {
    String[] row = new String[8];
    row[0] = line.substring(0, 7).trim();
    row[1] = line.substring(7, 15).trim();
    row[2] = line.substring(15, 24).trim();
    row[3] = line.substring(24, 35).trim();
    row[4] = line.substring(35, 46).trim();
    row[5] = line.substring(46, 53).trim();
    row[6] = line.substring(53, 57).trim();
    row[7] = line.substring(57).trim();
    return row;
  }

  public static void main(String[] args)
  {
    String[] resultLines = new String[] {
        "Handles   NPM(K)    PM(K)      WS(K)     CPU(s)   Id  SI  ProcessName                                                  ",
        "-------   ------    -----      -----     ------   --  -- -----------                                                  ",
        "    322      17     3308      13800              2572   0  armsvc                                                       ",
        "    171      10     6304      11224       0.11   3836   0  audiodg                                                      ",
        "    591      31    11864      42480       1.39   3660   9  backgroundTaskHost                                           ",
        "   1488      55    28736      61776              1892   0  CcmExec                                                      ",
        "     42       4     2332       3816       0.05  10720   9  cmd                                                          "
    };

    String[] columns = resultLines[0].split("\\s+");

    String[][] data = new String[resultLines.length - 2][];
    for (int i = 2; i < resultLines.length; i++) {
      data[i-2] = parseRow(resultLines[i]);
    }

    DefaultTableModel tableModel = new DefaultTableModel(data, columns);

    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(new JScrollPane(new JTable(tableModel)));
    frame.pack();
    frame.setVisible(true);
  }
}

版本 2

尝试我的程序的这个版本。这里，列数和列宽是动态计算的。

(calculateColumnWidths() 中使用的算法可能会得到增强。我只是想演示该方法。)

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

public class ParseTableData {

  public static int findFirstRowWithNoEmptyCells(String[] resultLines) {
    String[] columnNames = resultLines[0].split("\\s+");
    for (int i = 2; i < resultLines.length; i++) {
      String[] row = resultLines[i].trim().split("\\s+");

      if (columnNames.length == row.length) {
        return i;
      }
    }
    throw new IllegalStateException("Not a single complete row.");
  }

  public static int[] calculateColumnWidths(String rowWithNoEmptyCells) {
    int columnCount = rowWithNoEmptyCells.trim().split("\\s+").length;
    int[] columnWidths = new int[columnCount];

    int currentColumnIndex = 0;
    int currentWidth = 0;
    boolean nonSpaceCharFound = false;
    for (int i = 0; i < rowWithNoEmptyCells.length(); i++) {
      char c = rowWithNoEmptyCells.charAt(i);
      if (c == ' ') {
        if (!nonSpaceCharFound) {
          currentWidth++;
        }
        else {
          columnWidths[currentColumnIndex] = i;
          currentWidth = 1;
          nonSpaceCharFound = false;
          currentColumnIndex++;
        }
      }
      else {
        nonSpaceCharFound = true;
        currentWidth++;
      }
    }
    return columnWidths;
  }

  public static String[] parseRow(String line, int[] columnWidths) {
    String[] row = new String[columnWidths.length];
    for (int i = 0; i < row.length; i++) {
      if (i == 0) {
        row[i] = line.substring(0, columnWidths[i]).trim();
      }
      else if (i == row.length - 1) {
        row[i] = line.substring(columnWidths[i-1]).trim();
      }
      else {
        row[i] = line.substring(columnWidths[i-1], columnWidths[i]).trim();
      }
    }

    return row;
  }

  public static void main(String[] args)
  {
    String[] resultLines = new String[] {
        "Handles   NPM(K)    PM(K)      WS(K)     CPU(s)   Id  SI  ProcessName                                                  ",
        "-------   ------    -----      -----     ------   --  -- -----------                                                  ",
        "    322      17     3308      13800              2572   0  armsvc                                                       ",
        "    171      10     6304      11224       0.11   3836   0  audiodg                                                      ",
        "    591      31    11864      42480       1.39   3660   9  backgroundTaskHost                                           ",
        "   1488      55    28736      61776              1892   0  CcmExec                                                      ",
        "     42       4     2332       3816       0.05  10720   9  cmd                                                          "
    };

    int indexOfFirstRowWithNoEmptyCells = findFirstRowWithNoEmptyCells(resultLines);
    int[] columnWidths = calculateColumnWidths(resultLines[indexOfFirstRowWithNoEmptyCells]);

    String[] columns = resultLines[0].split("\\s+");

    String[][] data = new String[resultLines.length - 2][];
    for (int i = 2; i < resultLines.length; i++) {
      data[i-2] = parseRow(resultLines[i], columnWidths);
    }

    DefaultTableModel tableModel = new DefaultTableModel(data, columns);

    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(new JScrollPane(new JTable(tableModel)));
    frame.pack();
    frame.setVisible(true);
  }
}