java - 按元素将列表拆分为 block

Question

我有一个具有此模型的对象(Pos)集合:

public class Pos {
    private String beforeChangement;
    private String type;
    private String afterChangement;
}

对象列表如下:

[
Pos(beforeChangement=Découvrez, type=VER, afterChangement=découvrir), 
Pos(beforeChangement=un, type=DET, afterChangement=un),
Pos(beforeChangement=large, type=ADJ, afterChangement=large), 
Pos(beforeChangement=., type=SENT, afterChangement=.), 
Pos(beforeChangement=Livraison, type=NOM, afterChangement=livraison), 
Pos(beforeChangement=et, type=KON, afterChangement=et), 
Pos(beforeChangement=retour, type=NOM, afterChangement=retour), 
Pos(beforeChangement=., type=SENT, afterChangement=.), 
Pos(beforeChangement=achetez, type=VER, afterChangement=acheter), 
Pos(beforeChangement=gratuitement, type=ADV, afterChangement=gratuitement), 
Pos(beforeChangement=., type=SENT, afterChangement=.), 
Pos(beforeChangement=allez, type=VER, afterChangement=aller), 
Pos(beforeChangement=faites, type=VER, afterChangement=faire), 
Pos(beforeChangement=vite, type=ADV, afterChangement=vite), 
Pos(beforeChangement=chers, type=ADJ, afterChangement=cher), 
Pos(beforeChangement=clients, type=NOM, afterChangement=client)]
Pos(beforeChangement=., type=SENT, afterChangement=.)
]

我想按 beforeChangement 或 afterChangement == "."字段拆分此对象列表。具有这种格式(列表的列表)List<List<SOP>> :

[

[Pos(beforeChangement=Découvrez, type=VER, afterChangement=découvrir), 
Pos(beforeChangement=un, type=DET, afterChangement=un),
Pos(beforeChangement=large, type=ADJ, afterChangement=large)],

[Pos(beforeChangement=Livraison, type=NOM, afterChangement=livraison), 
Pos(beforeChangement=et, type=KON, afterChangement=et), 
Pos(beforeChangement=retour, type=NOM, afterChangement=retour)],

[Pos(beforeChangement=achetez, type=VER, afterChangement=acheter), 
Pos(beforeChangement=gratuitement, type=ADV, afterChangement=gratuitement)],


[Pos(beforeChangement=allez, type=VER, afterChangement=aller), 
Pos(beforeChangement=faites, type=VER, afterChangement=faire), 
Pos(beforeChangement=vite, type=ADV, afterChangement=vite), 
Pos(beforeChangement=chers, type=ADJ, afterChangement=cher), 
Pos(beforeChangement=clients, type=NOM, afterChangement=client)]

]

就像在按字符串“.”对象的字段分割后执行逆向 flatMap 以获得数组或列表( block )的列表

您知道如何使用 Streams 来做到这一点吗？

谢谢大家

Answer 1

嗯，我想使用这样的简单循环来解决您的问题:

List<List<Pos>> result = new ArrayList<>();
List<Pos> part = new ArrayList<>();
for(Pos pos : listPos){
    if(pos.getBeforeChangement().equals(".") || pos.getAfterChangement().equals(".")){
        result.add(part);//If the condition is correct then add the sub list to result list
        part = new ArrayList<>();// and reinitialize the sub-list
    } else {
        part.add(pos);// else just put the Pos object to the sub-list
    }
}
//Just in case the listPos not end with "." values then the last part should not be escaped
if(!part.isEmpty()){
    result.add(part);
}

---

注意，问题不够清楚，您的对象类名为 SOP ，对象列表为 Pos 哪个是正确的，在我的回答中，我基于 public class Pos{..} 而不是 public class SOP{..}。

---

• take a look at the Ideone demo