java - 如何有效地连接对象列表中的多个 String 变量？

Question

我想遍历一个对象列表并为每个变量连接几个字符串:

final StringBuilder xBuilder = new StringBuilder();
final StringBuilder yBuilder = new StringBuilder();
final StringBuilder zBuilder = new StringBuilder();

someObjects.forEach(obj -> {
  A a = obj.getA();
  xBuilder.append(obj.getX() + ",");
  yBuilder.append(obj.getY() + ",");
  zBuilder.append(a.getZ() + ",");
});

有没有比为每个变量创建多个 StringBuilder 更有效的方法？

Answer 1

好吧，您确实需要 3 个单独的字符串，因此创建 3 个 StringBuilder(s) 看起来很好。您也可以使用 StringJoiner 虽然:

StringJoiner xJoiner = new StringJoiner(",");
someObjects.forEach(obj -> {
    xJoiner.join(obj.getX();
});