Question

JTextArea中内容看不见

代码见链接
http://yun.baidu.com/share/link?shareid=1006085437&uk=3037160217&third=0

打开.txt或.java的文件后无法显示，但内容是存在的，因为再保存到新路径后有内容，但如果重新输入再保存就不行了，求助

Answer 1

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

public class JTextAreaLoadFile {
    public static void main(String args[]){
        new JTextAreaLoadFile().test();
    }

    void test(){
        new NoteFrame();
    }

    class NoteFrame extends JFrame  {
        public NoteFrame() {
            this.setLocation(200, 200);
            setTitle("MINI JAVA IDE");

            Container c = getContentPane();
            add((p1 = new TextPanel()) );
            
            JMenuBar menubar = new JMenuBar();
            this.setJMenuBar(menubar);

            JMenu fileMenu = new JMenu("文件");

            JMenuItem newItem = new JMenuItem("新建");
            newItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    p1.area1.setText("");
                }
            });
            fileMenu.add(newItem);

            JMenuItem openItem = new JMenuItem("打开");
            openItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e){
                    JFileChooser chooser = new JFileChooser();
                    chooser.setCurrentDirectory(new File("."));
                    chooser.showOpenDialog(NoteFrame.this);
                    filePath = chooser.getSelectedFile().getPath();
                    try{
                        File f = new File(filePath);

                        FileInputStream in = new FileInputStream(f);
                        int n = in.available();
                        byte[] b = new byte[n];
                        in.read(b, 0, n);

                        fileText = new String(b);
                        p1.area1.setText(fileText);
                    }
                    catch (IOException e1){

                    }
                }
            });
            fileMenu.add(openItem);

            JMenuItem saveItem = new JMenuItem("保存");
            saveItem.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    JFileChooser chooser = new JFileChooser();
                    chooser.setCurrentDirectory(new File("."));
                    chooser.showSaveDialog(NoteFrame.this);
                    String filePath = chooser.getSelectedFile().getPath();
                    try {
                        FileWriter out = new FileWriter(new File(filePath));
                        out.write(p1.area1.getText());
                        out.flush();
                    } catch (IOException e1){

                    }
                }
            });
            fileMenu.add(saveItem);

            JMenuItem exitItem = new JMenuItem("退出");
            exitItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    System.exit(0);
                }
            });
            fileMenu.add(exitItem);

            JMenu editMenu = new JMenu("编辑");

            JMenuItem copyItem = new JMenuItem("复制");
            copyItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    p1.area1.copy();
                }
            });
            editMenu.add(copyItem);

            JMenuItem cutItem = new JMenuItem("剪切");
            cutItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    p1.area1.cut();
                }
            });
            editMenu.add(cutItem);

            JMenuItem pasteItem = new JMenuItem("粘贴");
            pasteItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    p1.area1.paste();
                }
            });
            editMenu.add(pasteItem);

            JMenu proMenu = new JMenu("编译");
            JMenuItem debugItem = new JMenuItem("调试");
            debugItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    String str = p1.area1.getText();
                    Runtime ce = Runtime.getRuntime();
                    Process process = null;
                    try {
                        process = ce.exec("javac " + filePath);
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    BufferedInputStream is = new BufferedInputStream(process.getErrorStream());
                    byte[] buf = new byte[4096];
                    int n = -1;
                    boolean boo;
                    boolean boo1 = true;
                    try {
                        while ((n = is.read(buf, 0, buf.length)) != -1) {

                            boo = false;
                            boo1 = false;
                        }
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    if (boo1) {
                        p1.area2.append("\n调试成功！");
                        boo = true;
                    } else {
                        p1.area2.append("\n调试失败！");
                        boo1 = true;
                    }
                    try {
                        is.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    process.destroy();
                }
            });
            proMenu.add(debugItem);

            JMenuItem runItem = new JMenuItem("运行");
            runItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                    Runtime ce = Runtime.getRuntime();
                    byte[] buf = new byte[4096];
                    int n = -1;
                    String s1 = filePath;
                    int i=s1.lastIndexOf("\\");
                    int j=s1.lastIndexOf(".");
                    String s2 = s1.substring(i+1, j);
                    //取出文件名，存入s2
                    Process process1 = null;
                    try {
                        process1 = ce.exec("java " + s2);
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    BufferedInputStream bis = new BufferedInputStream(process1.getInputStream());
                    try {
                        while ((n = bis.read(buf, 0, buf.length)) != -1) {
                            p1.area2.append('\n' + new String(buf, 0, n));
                        }
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    try {
                        bis.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                    process1.destroy();
                }
            });
            proMenu.add(runItem);


            JMenu helpMenu = new JMenu("帮助");
            JMenuItem aboutItem = new JMenuItem("快捷键");
            aboutItem.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e){
                    JOptionPane.showMessageDialog(null, "提示：\nCtrl+C:复制\nCtrl+V:粘贴\nCtrl+X:剪切\nCtrl+A:全选");
                }
            });
            helpMenu.add(aboutItem);
            menubar.add(fileMenu);
            menubar.add(editMenu);
            menubar.add(proMenu);
            menubar.add(helpMenu);
            pack();// 使用该语句,使panel的大小与frame相适应
            p1.area1.setText(fileText);
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setVisible(true);
        }


        public String fileText, filePath;

        public String title;

        public TextPanel p1;
    }


    class TextPanel extends JPanel {
        public TextPanel() {
            this.setLayout(new BorderLayout());
            this.setSize(200, 200);
            area1 = new JTextArea(20, 40);
            area2 = new JTextArea(20, 40);
            area2.setEditable(false);
            JScrollPane scroll1 = new JScrollPane(area1);
            add(scroll1, BorderLayout.NORTH);

            JScrollPane scroll2 = new JScrollPane(area2);
            add(scroll2, BorderLayout.SOUTH);
        }

        public JTextArea area1;
        public JTextArea area2;
    }
}