convert Arraylist into json

please help how could we convert the below Arraylist method into Json

public ArrayList<String> helloName(String patentno)  {

    ArrayList<String> bibo = new ArrayList<String>();

    for (int row = 2; row < rowsize; row++) {
        pno = driver.findElement(
                By.xpath("//*[@id='body']/table/tbody/tr[" + row + "]/td"))
                .getText();
        bibo.add(pno);
    }
    return bibo;
}