如何从CSV文件输出特定行的内容？

Question

The goal of my code is to ask the user for an input, and my code will search my CSV file and output the correct row and column the data lies. However, I'm quite stumped as to how to extract that specific cell so I can then edit the contents.

Say I search for banana and my code searches for banana and then outputs that specific row which will include banana,store to a variable so I can then edit the location, and put it back in the correct cell.

Here's the code for finding the row and column of the specific text I search for:

try{

        String strSearch = searchSerialField.getText();

        CSVReader reader = new CSVReader(new FileReader("test.txt"), ',');
        List<String[]> myEntries = reader.readAll();
        reader.close();

        for (int row = 0; row < myEntries.size(); row++)
        {
            for (int column = 0; column < myEntries.get(row).length; column++)
            {
                if (myEntries.get(row)[column].trim().equalsIgnoreCase(strSearch))
                {
                    System.out.println("Found - Your item is on row: " + row + ", column: " + column);
                }
            }
        }

//I now need to output the contents of the row into something so I can edit it

I'm now just needing to extract the row into something so I can then edit the location, but I'm clueless as to how I should be approaching this?

If anyone has any tips or methods I should be following, then that would be greatly appreciated.

Thank you.

Answer 1

Java String s are immutable; you can't change them, you have to create new ones. List s and arrays, on the other hand are mutable (unless they're not).

You can do...

for (int row = 0; row < myEntries.size(); row++)
{
    for (int column = 0; column < myEntries.get(row).length; column++)
    {
        if (myEntries.get(row)[column].trim().equalsIgnoreCase(strSearch))
        {
            System.out.println("Found - Your item is on row: " + row + ", column: " + column);
            String myNewString = "something else";
            myEntries.get(row)[column] = myNewString;  // Replaces the String at this array index
        }
    }
}

// Now write the contents to a CSVWriter variable called 'myCSVWriter'
for (String[] entry : myEntries) {
    myCSVWriter.writeNext(entry);
}
myCSVWriter.close();

// Actually -- instead of that -- an easier way would be...
myCSVWriter.writeAll(myEntries);
myCSVWriter.close();

When you're done, you can use the myEntries collection to overwrite the contents of the file.