以下代码将 element -Array放大1，从而使您可以在新创建的最后一个索引中放入内容.然后只需保存该数组即可.

The following "enlarges" the element-Array by one, enabling you to put something in the newly created last index. Then just save that array.

import java.util.Arrays;

    String element[] = null;
    while((element = reader.readNext()) != null){
        element = Arrays.copyOf(element, element.length + 1);
        element[element.length - 1] = "JSON";
        writer.writeNext(element);
    }