Question

我正在研究从.txt文件中读取文本的JTable。 txt文件在3秒后动态更新。现在当我运行应用程序时，一切都很好，除了.txt文件的输出来自第二行的JTable。第一行txt文件没有出现在我的JTable上。有人可以帮忙吗？这是代码：

public class InterfaceFrame extends JFrame implements ActionListener{

public static void main(String[] args) throws
URISyntaxException,
IOException,
InterruptedException {
    panel.setSize(100,100);
      panel.add(table);
      model.fireTableStructureChanged();

        table.setModel(model);
        InsertFileToJtable model = new InsertFileToJtable();
      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
      table.setFillsViewportHeight(true);

      RowSorter<TableModel> sorter =
              new TableRowSorter<TableModel>(model);
            table.setRowSorter(sorter);

        JScrollPane scrollpane = new JScrollPane(table);
        panel.add(scrollpane, BorderLayout.CENTER);

        JButton button = new JButton("Show View");
        panel.add( button, BorderLayout.SOUTH );


        tabbedPane.addTab("Process",null,scrollpane,"");
}

我在编写文本文件时可能会出错。这是生成.txt文件的代码。：

import java.io.*;
import java.util.StringTokenizer;


public class GetProcessList
{

 private String GetProcessListData()
 {
 Process p;
 Runtime runTime;
 String process = null;
 try {
 System.out.println("Processes Reading is started...");

 //Get Runtime environment of System
 runTime = Runtime.getRuntime();

 //Execute command thru Runtime
 p=runTime.exec("ps -e");              //For Linux

 //Create Inputstream for Read Processes
 InputStream inputStream = p.getInputStream();
 InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
 BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

 //Read the processes from sysrtem and add & as delimeter for tokenize the output
 String line = bufferedReader.readLine();
 process = "&";
 while (line != null) {
 line = bufferedReader.readLine();
 process += line + "&";
 }

 //Close the Streams
 bufferedReader.close();
 inputStreamReader.close();
 inputStream.close();

 System.out.println("Processes are read.");
 } catch (IOException e) {
 System.out.println("Exception arise during the read Processes");
 e.printStackTrace();
}
    return process;
 }

 void showProcessData()
 {
 try {

 //Call the method For Read the process
 String proc = GetProcessListData();

 //Create Streams for write processes
 //Given the filepath which you need.Its store the file at where your java file.
 OutputStreamWriter outputStreamWriter =
 new OutputStreamWriter(new FileOutputStream("ProcessList.txt"));
 BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);

 //Tokenize the output for write the processes
 StringTokenizer st = new StringTokenizer(proc, "&");

 while (st.hasMoreTokens()) {
 bufferedWriter.write(st.nextToken());  //Write the data in file
 bufferedWriter.newLine();               //Allocate new line for next line
 }

 //Close the outputStreams
 bufferedWriter.close();
 outputStreamWriter.close();

 } catch (IOException ioe) {
 ioe.printStackTrace();
 }

 }
}

下面是代码，它读取ProcessList.txt并将输出提供给JTable：

import java.io.*;
import java.awt.*;
import java.util.*;import javax.swing.*;
import java.awt.event.*;
import javax.swing.table.*;

public class InsertFileToJtable extends AbstractTableModel{
Vector data;
Vector columns;
private String[] colNames = {"<html><b>PID</b></html>","<html><b>TTY</b</html>",<html>  <b>time</b></html>","<html><b>Process Name</b></html>",};


public InsertFileToJtable() {
String line;
data = new Vector();
columns = new Vector();
  try {
        FileInputStream fis = new FileInputStream("ProcessList.txt");
        BufferedReader br = new BufferedReader(new InputStreamReader(fis));
        StringTokenizer st1 = new StringTokenizer(br.readLine(), " ");
        while (st1.hasMoreTokens())
                columns.addElement(st1.nextToken());
        while ((line = br.readLine()) != null) {
                StringTokenizer st2 = new StringTokenizer(line, " ");
                while (st2.hasMoreTokens())
                       data.addElement(st2.nextToken());
        }
        br.close();
} catch (Exception e) {
        e.printStackTrace();
}  

}

public int getRowCount() {
return data.size() / getColumnCount();
}

public int getColumnCount() {
return columns.size();
}

public Object getValueAt(int rowIndex, int columnIndex) {
return (String) data.elementAt((rowIndex * getColumnCount())
                + columnIndex);
}
@Override
public String getColumnName(int column) {
return colNames[column];
}
@Override
public Class getColumnClass(int col){
return getValueAt(0,col).getClass();
}
}

Answer 1

我的做法略有不同，避免使用中间文本文件。取而代之的是，

使用ProcessBuilder，“可以从同一个实例重复调用”。您可以阅读here所示的输出并将其解析为合适的数据结构，例如List<List<String>>。
```
ProcessBuilder pb = new ProcessBuilder("ps -ef");
```
开始一个有三秒钟的javax.swing.Timer;在计时器的监听器中调用pb.start()。
解析结束时，fireTableDataChanged()中的AbstractTableModel显示为here。

Presto，您的表每三秒更新一次最新结果。

JTable从第二行读取文本文件

1 个答案: