求助～！这个程序实现思路对吗？

Question

请编写一个字符输入流的包装类，通过这个包装类对底层字符输入流进行包装，让程序通过这个包装类读取某个文本文件（例如，一个java源文件）时，能够在读取的每行前面都加上有行号和冒import java.net.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
public class AddLine
{
  public static void main(String[] args)
  {
        JFrame jf = new JFrame("Hello");
        jf.setSize(600,400);
        jf.setLocation(100,100);
        JPanel p = new JPanel();
        JLabel l = new JLabel("Open File:");
      
        final JTextField tf = new JTextField(30);
        p.add(l);
        p.add(tf);
        jf.getContentPane().add(p,"North");
        final JTextArea ta = new JTextArea();
        jf.getContentPane().add(ta,"Center");
        JButton btn = new JButton("Open");
        jf.getContentPane().add(btn,"north");
        byte b[] = new byte [1024*10];
        String s;
        final String str = tf.getText();
        btn.addActionListener(new ActionListener() {
              public void actionPerformed(ActionEvent e) {
              try
               {
                    FileInputStream fis = new FileInputStream(str);
                    DataInputStream din = new DataInputStream(fis);
                                
                    String line = System.getProperty("line.separator");
                    int len = 0;
               byte b[] = new byte[1024*10];          
                    while((b = din.readLine())!=null)
                     {     
                          ta.append(++len + ": ");
                          ta.append(b);
                          ta.append(line.getBytes());
                     }
                     
                         fis.close();
                    }
           
             catch (Exception ex) 
              {
               ex.printStackTrace();
              }        }
      });
        
        
    jf.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
           System.exit(0);
         }
       });
    jf.show();
  }
}            

Answer 1

不懂 swing 
帮忙顶

Answer 2

不知道你为什么要写一个swing的界面出来，
从要求来看，你只要把中间的一段
  try
               {
                    FileInputStream fis = new FileInputStream(str);
                    DataInputStream din = new DataInputStream(fis);
                                
                    String line = System.getProperty("line.separator");
                    int len = 0;
               byte b[] = new byte[1024*10];          
                    while((b = din.readLine())!=null)
                     {     
                          ta.append(++len + ": ");
                          ta.append(b);
                          ta.append(line.getBytes());
                     }
                     
                         fis.close();
                    }包装成一个类，提供一个readline方法就好了。

Answer 3

public class AddLine
{
    public static void main(String[] args)
    {
        JFrame jf = new JFrame("Hello");
        jf.setSize(600, 400);
        jf.setLocation(100, 100);
        JPanel p = new JPanel();
        JLabel l = new JLabel("Open File:");        final JTextField tf = new JTextField(30);
        p.add(l);
        p.add(tf);
        jf.getContentPane().add(p, "North");
        final JTextArea ta = new JTextArea();
        jf.getContentPane().add(ta, "Center");
        JButton btn = new JButton("Open");
        jf.getContentPane().add(btn, "North");
        byte b[] = new byte[1024 * 10];        btn.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                String str = ta.getText();
                try
                {
                    FileInputStream fis = new FileInputStream(new File(str));
                    ta.setText("");
                    BufferedReader br = new BufferedReader(new InputStreamReader(fis)) ;
//                    DataInputStream din = new DataInputStream(fis);                    String line = System.getProperty("line.separator");
                    int len = 0;
                    byte b[] = new byte[1024 * 10];
                    String s ;
                    while ((s = br.readLine()) != null)
                    {
                        ta.append(++len + ": ");
                        ta.append(s);
//                        ta.append(line.getBytes());
                        ta.append(line);
                    }                    fis.close();
                }                catch (Exception ex)
                {
                    ex.printStackTrace();
                }            }
        });        jf.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
        jf.setVisible(true);
    }
}大概改了一下，需要在textarea中输入文件的绝对路径

Answer 4

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;/**
 * @author songy
 *
 */
public class NewInputStream {
static BufferedReader bufferedReader = null;
static int index = 0;
/**
 * 
 */
public NewInputStream(BufferedReader bufferedReader) {
this.bufferedReader = bufferedReader;
} /* (non-Javadoc)
 * @see java.io.InputStream#read()
 */

public String readLine() throws IOException {
index ++;
String currentLine = bufferedReader.readLine();
if (currentLine != null ){
return String.valueOf(index) + ": " + currentLine; 
} else {
return null;
}
}

public void close() throws IOException {
bufferedReader.close();
}

public static void main(String[] args) {
NewInputStream newInputStream = null;
                  if (args.length != 1) {
System.err.println("Usage: java NewInputStream [fileName]");
System.exit(1);
}
try {
newInputStream = new NewInputStream(new BufferedReader(new FileReader(args[0])));
String currentLine = "";
while ((currentLine = newInputStream.readLine()) != null) {
System.out.println(currentLine);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {newInputStream.close();} catch (IOException e) { }
}
}

}所谓包装类应该类似于BufferdReader之于FileReader，提供一个更高层次的接口，所以并不应该写成LZ的形式。

Answer 5

把main去掉了用就可以了~但是不能使用流标记、重置。