java - 调用一个类的构造函数来修改它以在另一个类中使用

Question

该程序的目的是读取文件并将其写入文本文件。

为此我有三个类(class):

Class ReadFile //Reads and displays text from the text file

Class WriteFile //Gets input from user and puts it writes it to the text file 

Class Application //Holds the Main method for execution.

在 WriteFile 类中，我有代码将文本追加(添加)到文本文件或不追加(删除文本文件中的所有内容，然后将输入写入文本文件，这是通过此完成的)代码在这里

public class WriteFile 
{

private String path;
private boolean append_to_file = false;

public WriteFile(String file_path)
{
    path = file_path;
}

public WriteFile (String file_path, boolean append_value)
{
    path = file_path;
    append_to_file = append_value;
}

public void writeToFile(String textLine) throws IOException
{
    FileWriter write = new FileWriter(path);
    PrintWriter print_line = new PrintWriter(write);

    print_line.printf("%s" + "%n", textLine);
    print_line.close();
}
}

现在决定是否将数据附加到文本文件的唯一方法是注释掉

append_to_file = append_value;

用户当然无法做到这一点。我想给用户这个选项。

所以我想我可以将其添加到类应用程序中，该应用程序包含接收输入的代码。

public class Application 
{

public static void main(String[] args) throws IOException
{



String file_name = "Q:/test.txt";

try
{

    ReadFile file = new ReadFile(file_name);
    String[] aryLines = file.OpenFile();

    for(int i = 0; i < aryLines.length; i++)
    {
        System.out.println(aryLines[i]);    
    }
}

catch (IOException e)
{
    System.out.println( e.getMessage());
}

//boolean End = false;
String userEnter;
Scanner input = new Scanner (System.in);

for(int i = 0; i < 10; i++)
{
System.out.println("\n\nenter text to write to file");
userEnter = input.nextLine();

WriteFile data = new WriteFile(file_name, true);
data.writeToFile( userEnter );

System.out.println( "Text File Written To" );
}

}
}

如何编写代码来为用户提供附加数据的选项？

如果有帮助的话，这是类 ReadFile

public class ReadFile 
{
private String path;

public ReadFile (String file_path)
{
    path = file_path;
}

public String[] OpenFile() throws IOException
{
    FileReader fr = new FileReader(path);
    BufferedReader textReader = new BufferedReader(fr);

    int numberOfLines = readLines();
    String[] textData = new String [numberOfLines];



    for(int i = 0; i < numberOfLines; i++)
    {
        textData[i] = textReader.readLine();
    }

    textReader.close();
    return textData;
}

int readLines() throws IOException
{
    FileReader file_to_read = new FileReader(path);
    BufferedReader bf = new BufferedReader(file_to_read);

    String aLine;
    int numberOfLines = 0;

    while ((aLine = bf.readLine()) != null)
    {
        numberOfLines++;
    }
    bf.close();
    return numberOfLines;
}

}

我希望我解释清楚

谢谢你 凯尔

Answer 1

如果您希望用户始终追加或始终覆盖一组特定的行，您可以执行以下操作:

System.out.println("Enter false to overwrite data, or true to append data");
userEnter = input.nextLine();
boolean append = Boolean.parseBoolean(userEnter);

如果您将这些行放在循环之外，用户将被询问一次，并且将始终使用相同的值，或者您可以将其放在循环内每次都询问。

WriteFile data = new WriteFile(file_name, append);