如何在Java类中制作FileInputStream和FileOutputStream

Question

I wrote two methods to write and read data from Internal Storage, now that I want to put them in a non activity class I get errors at openFileOutput and openFileInput that says the method openFileInput / openFileOutput is undefined for the type IOstream(name of my class)

I don't know how to fix it.

public void write(String fileName, String content) throws IOException{
    FileOutputStream outStream = openFileOutput(fileName, Context.MODE_PRIVATE);
    outStream.write(content.getBytes());
    outStream.close();
}

public String read(String fileName) throws IOException{
    FileInputStream inStream = openFileInput(fileName);

    String content = null;
    byte[] readByte = new byte[inStream.available()];

    while(inStream.read(readByte) != -1){
        content = new String(readByte);
    }
    inStream.close();
    return content;
}

I'm looking for a way to put these methods in their own class

Answer 1

When you post a question and say "I get errors", actually posting said errors would go a long way to show people your problem.

Taking a guess from your question and code, you've moved those methods to a class that does not extend Context, where those two methods are declared, so they can't be found.

You need a reference to a context to be able to access those methods.

public void write(Context context, String fileName, String content) throws IOException{
    FileOutputStream outStream = context.openFileOutput(fileName, Context.MODE_PRIVATE);
    outStream.write(content.getBytes());
    outStream.close();
}

public String read(Context context, String fileName) throws IOException{
    FileInputStream inStream = context.openFileInput(fileName);

    String content = null;
    byte[] readByte = new byte[inStream.available()];

    while(inStream.read(readByte) != -1){
        content = new String(readByte);
    }
    inStream.close();
    return content;
}