将StringBuilder附加到JTextArea

Question

我试图让自己成为一个文字处理器。我只熟悉JFileChooser的概念，并将其实现到我的代码中。我希望能够使用JFileChooser来打开文本文件并将文本文件的内容附加到JTextArea。为了尽我所能分离我的功能，我实现了MVC（模型视图控制器），所以我有3个类。该视图称为WordFrame.java，模型称为DataStuff.java，控制器称为ProcessEvents.java。我的问题很简单，我可以将文本文件的内容打印到控制台，但试图将所述内容附加到TextArea只会产生空白区域，下图显示了textArea上的位置，表示其字符间距，这是在文件加载后。如上所述，控制台可以完美地打印出来。

也，这里是模型和控制器

import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.io.File; 
import java.util.Scanner; 


public class ProcessEvents { 

    private WordFrame frame = new WordFrame(); 
    private DataStuff data = new DataStuff(); 
    private DialogBoxes dialogs = new DialogBoxes(); 
    private boolean fileSaved; 
    String fileName = ""; 
    int fontSize = 0; 
    public ProcessEvents(WordFrame frame, DataStuff data){ 
     this.frame = frame; 
     this.data = data; 
     this.frame.addListener(new wordProcessListener()); 
    } 
    class wordProcessListener implements ActionListener{ 

     @Override 
     public void actionPerformed(ActionEvent e) { 
      if(e.getSource().equals(frame.openMenuItem)){ 
       frame.fileChooser.showOpenDialog(frame); 
       File f = frame.fileChooser.getSelectedFile(); 

       System.out.println("Command Executed: open"); 

       data.loadFile(f.getAbsoluteFile()); 

       if(data.showText() != null){ 
        String texts = data.showText().toString(); 

        System.out.println(data.showText()); 

        frame.textArea.append(data.showText().toString()); 
       } 
      } 
      if(e.getSource().equals(frame.FontMenuItem)){ 
       System.out.println("font"); 
      } 
      if(e.getSource().equals(frame.exitMenuItem)){ 
       dialogs.getConfirmDialog("exitWithoutSave"); 
      } 

      if(e.getSource().equals(frame.saveMenuItem)){ 
       dialogs.getSaveFileDialog(); 
       data.saveFile("Bingo"); 
       fileSaved = true; 
      } 
      if(e.getSource().equals(dialogs.close)){ 
       if(!fileSaved){ 

       } 
      } 
     } 

    } 
} 

这里的代码模型

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 

public class DataStuff { 
    private String fileName = ""; 
    private File file; 

    String text; 
    String name; 
    private File saveFile; 
    int counter = 0; 
    FileInputStream fis = null; 
    FileOutputStream fout = null; 
    StringBuilder sb; 
    char[] charArray; 
    int count = 0; 
    public void loadFile(File fileName){ 
     this.file = fileName; 
     try{ 
      fis = new FileInputStream(file); 
      charArray = new char[fis.read()]; 
      while ((counter = fis.read()) != -1) { 

       System.out.print((char) counter); 
       sb = new StringBuilder(); 
       sb.append(charArray); 

      } 

     } 
     catch(IOException ex){ 
      ex.printStackTrace(); 
     } 
     finally { 
      try { 
       if (fis != null) 
        fis.close(); 
      } catch (IOException ex) { 
       ex.printStackTrace(); 
      } 
     } 
    } 
    public StringBuilder showText(){ 

     return sb; 

    } 
    public void saveFile(String name) { 
     this.name = name; 
     try{ 
     fout = new FileOutputStream(saveFile+"/"+name+".txt"); 
     } 
     catch(IOException e){ 
      System.out.println("File failed to save or something went horribly wrong"); 
     } 
    } 
} 

，并一如既往地支持总是赞赏。

编辑：所以我实际上在下面的人的帮助下修复了这个解决方案，我决定我不想替换上面的代码，以防万一别人在同一个问题上磕磕绊绊，可以看到差异，这里是视图类再次进行调整。

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 

public class DataStuff { 
    private String fileName = ""; 
    private File file; 

    String text; 
    String name; 
    private File saveFile; 
    int counter = 0; 
    FileInputStream fis = null; 
    FileOutputStream fout = null; 
    StringBuilder sb = new StringBuilder(4096); 
    //char[] charArray = new char[4096]; 
    int count = 0; 
    public void loadFile(File fileName){ 
     this.file = fileName; 
     try{ 
      fis = new FileInputStream(file); 
     // charArray = Character.toChars(fis.read()); 
      while ((counter = fis.read()) != -1) { 

       System.out.print((char) counter); 

       sb.append((char) counter); 

      } 

     } 
     catch(IOException ex){ 
      ex.printStackTrace(); 
     } 
     finally { 
      try { 
       if (fis != null) 
        fis.close(); 
      } catch (IOException ex) { 
       ex.printStackTrace(); 
      } 
     } 
    } 
    public StringBuilder showText(){ 

     return sb; 

    } 
    public void saveFile(String name) { 
     this.name = name; 
     try{ 
     fout = new FileOutputStream(saveFile+"/"+name+".txt"); 
     } 
     catch(IOException e){ 
      System.out.println("File failed to save or something went horribly wrong"); 
     } 
    } 
} 

Answer 1

在第一次审查它看起来像你正在创建每次循环迭代一个新的字符串生成器，而不是重新使用。您应该在开始while循环之前创建stringbuilder，并在每次迭代时简单地附加读取字符。