Java 使用唯一和重复数据拆分数据帧

输入数据帧：

df=
+---+---+---+---+---+
|  1|  2|  3|  4|  5|
+---+---+---+---+---+
|  a|  b|  c|  d|  E|
|  a|  b|  c|  d|  F|
|  a|  b|  d|  d|  H|
|  a|  c|  c|  d|  E|
|  a|  a|  c|  d|  E|
|  a|  b|  c|  d|  L|
|  a|  c|  c|  d|  E|
+---+---+---+---+---+`

代码

但是我需要一个b的输出

b.show();
+---+---+---+---+---+
|  1|  2|  3|  4|  5|
+---+---+---+---+---+
|  a|  b|  c|  d|  L|
|  a|  b|  c|  d|  F|
|  a|  c|  c|  d|  E|
+---+---+---+---+---+

---

您所需的输出不正确

exceptAll

a.show();
+---+---+---+---+---+
|  1|  2|  3|  4|  5|
+---+---+---+---+---+
|  a|  a|  c|  d|  E|
|  a|  b|  c|  d|  E|
|  a|  b|  d|  d|  H|
|  a|  c|  c|  d|  E|
+---+---+---+---+---+`

b.show();
+---+---+---+---+---+
|  1|  2|  3|  4|  5|
+---+---+---+---+---+
|  a|  b|  c|  d|  L|
|  a|  b|  c|  d|  F|
+---+---+---+---+---+`

b.show();
+---+---+---+---+---+
|  1|  2|  3|  4|  5|
+---+---+---+---+---+
|  a|  b|  c|  d|  L|
|  a|  b|  c|  d|  F|
|  a|  c|  c|  d|  E|
+---+---+---+---+---+