What is the best approach to code in java?

by using constructors for example:

class MyInputStream {
    private InputStream inputStream;  

    public InputStream getInputStream() {
        return inputStream;
    }

    MyInputStream(String filename) throws FileNotFoundException {
       inputStream = new FileInputStream(filename);
   }

by using parameterized methods directly to get return value. for example:

public InputStream getInputStream(String filename) throws FileNotFoundException {
    InputStream inputStream;   
    inputStream = new FileInputStream(filename);
    return inputStream; 
}

by using getter setter without constructor

class MyInputStream {
    private InputStream inputStream;

    public InputStream getInputStream() {
        return inputStream;
    }

    ...
    ...
}   

or any other good professional time and resource saving dynamic universal good practice