Question

在Java控制台上打印.dat的正确方法是什么？

public void open(){
    try {
        FileInputStream inFile =
            new FileInputStream("C:"+File.separatorChar+"transactions.dat");
        ObjectInputStream in = new ObjectInputStream(inFile);
        //While (in.readLine!=null){
            System.out.print(in.readLine());}
        in.close();
    } catch (FileNotFoundException ex) {
        System.out.println(ex);
    } catch (Exception ex) {
        ex.printStackTrace();
    } finally{  }
}

这仅给出一行的结果，并且字符具有不同的大小如何读取所有数据并使用可读输出打印到控制台上！

当我在这个dat文件中写入原文时，我使用

FileOutputStream outFile =
    new FileOutputStream("C:"+File.separatorChar+"transactions.dat");
ObjectOutputStream out = new ObjectOutputStream(outFile);
out.writeChars(brokerageAcc1.toString());

Answer 1

FileInputStream fis = new FileInputStream("C:"+File.separatorChar+"transactions.dat");
BufferedReader br=new BufferedReader(new InputStreamReader(fis));
String s;
while ((s=br.readline())!=null)
    System.out.println(s);

Answer 2

如果这是你正在编写和阅读的文本，那么你应该使用Writer和Reader类，用BufferedWriter和BufferedReader包装来提供行处理。

FileOutputStream outFile =
    new FileOutputStream("C:"+File.separatorChar+"transactions.dat");
BufferedWriter writer = new BufferedWriter(new Writer(outFile));
writer.write(Acc1.toString());
// maybe write a newline??
writer.newLine();

然后使用缓冲读卡器将其读回来：

FileInputStream inFile =
    new FileInputStream("C:"+File.separatorChar+"transactions.dat");
BufferedReader reader = new BufferedReader(new InputStreamReader(inFile));
while (true) {
    String line = reader.readline();
    if (line == null) break;
    System.out.println(line);
}

Answer 3

如果控制台上的字符大小不同，则控制台本身配置为显示带有比例字体的文本。这必须在控制台上进行调整，无法通过Java应用程序进行控制。

您正在写信ObjectOutputStream。这有点奇怪，但您可能需要这个。要从这样的文件中读取，请使用以下代码（注意：我稍微改变了您的写入算法！不包括流关闭和异常处理）

// writing

FileOutputStream outFile = new FileOutputStream("C:"+File.separatorChar+"transactions.dat");
ObjectOutputStream out = new ObjectOutputStream(outFile);

String s = brokerageAcc1.toString();
out.writeInt(s.length());
System.out.println(s.length());

out.writeChars(s);

// reading

FileInputStream inFile = new FileInputStream("C:"+File.separatorChar+"transactions.dat");
ObjectInputStream in = new ObjectInputStream(inFile);
int length = in.readInt();     // get the number of chars
System.out.println(""+length);
StringBuilder result = new StringBuilder();
for (int i = 0; i < length; i++)
  result.append(in.readChar());
System.out.println(result.toString());

在Java控制台上打印.dat的正确方法是什么？

3 个答案: