如何从文本文件中读取多个对象，然后发送到 ArrayList？

Question

I currently have my program reading the first object using BufferedReader but I am unsure how to read more then one object. Here is the code that I have reading from the file:

    public Stock getData(){

    StringTokenizer row;
    Stock aStock = new Stock();

    try{
        BufferedReader inbuffer = new BufferedReader(new FileReader(fileName));
        String inputString;
        inputString = inbuffer.readLine();
        if(inputString != null){
            row = new StringTokenizer(inputString, DELIMTER);
            if(row.countTokens() == 4){
                aStock.setStockName(row.nextToken());
                aStock.setStockQuantity(Integer.parseInt(row.nextToken()));
                aStock.setPurchasePrice(Double.parseDouble(row.nextToken()));
                aStock.setCurrentPrice(Double.parseDouble(row.nextToken()));

            }
        }
        inbuffer.close();
    }
    catch(IOException ioe){
        JOptionPane.showMessageDialog(null, ioe.getMessage(), "File Read Error", JOptionPane.ERROR);
    }
    return aStock;
}

The file I am reading from looks like this:

and then the section of code that calls to my bufferedReader looks like this:

    public void loadFile(){
    StockIO stockRead = new StockIO();
    jFileChooser1.showOpenDialog(jPanel3);
    File file = jFileChooser1.getSelectedFile();
    stockRead.loadFileName(file.getName());
    stockArr.add(stockRead.getData());

    int index = 0;
    if(stockArr.get(index) != null){
        DLM.addElement(stockArr.get(0).getStockName());
        index ++;
    }


    listStock.setModel(DLM);

}

So I am trying to get it where my bufferedReader will read and send both lines of code through.Currently if I run this it will send through the "Shawn" line with all object information but I want the "test" line as well. Thank you for your time looking at this.

Answer 1

Your code is currently stopping after it reads the first line because there is no loop to continue iterating through your whole file.

You can use a while loop to check if there is a line to read while looping through your lines:

while ((line = inbuffer.readLine()) != null) {
   // Process each line
}

import java.util.ArrayList;

public ArrayList<Stock> getData(){

    StringTokenizer row;

    ArrayList<Stock> stockList = new ArrayList<>();

    try{
        BufferedReader inbuffer = new BufferedReader(new FileReader(fileName));
        String inputString;
        Stock aStock;
        // inputString = inbuffer.readLine();
        while ((line = inbuffer.readLine()) != null){
            row = new StringTokenizer(line, DELIMTER);
            if(row.countTokens() == 4){
                aStock = new Stock();
                aStock.setStockName(row.nextToken());
                aStock.setStockQuantity(Integer.parseInt(row.nextToken()));
                aStock.setPurchasePrice(Double.parseDouble(row.nextToken()));
                aStock.setCurrentPrice(Double.parseDouble(row.nextToken()));
                stockList.add(aStock);
            }
        }
        inbuffer.close();
    }
    catch(IOException ioe){
        JOptionPane.showMessageDialog(null, ioe.getMessage(), "File Read Error", JOptionPane.ERROR);
    }

    return stockList;
}

It also looks like you also need to add a loop in your loadFile() method to iterate through all of your stocks.

public void loadFile(){
    StockIO stockRead = new StockIO();
    jFileChooser1.showOpenDialog(jPanel3);
    File file = jFileChooser1.getSelectedFile();
    stockRead.loadFileName(file.getName());

    // Add all new stocks from getData to stockArr
    stockArr.addAll(stockRead.getData());

    // int index = 0;
    for (int index = 0; index < stockArr.length; index++) {
        if(stockArr.get(index) != null){
            DLM.addElement(stockArr.get(index).getStockName());
        }
    }

    listStock.setModel(DLM);

}