排序后如何删除数组中特定的重复数据?

Question

这是我的代码:

FileWriter writers = null;
try {
BufferedReader reader = new BufferedReader(new FileReader("Database.txt"));
ArrayList<Data> dataList = new ArrayList<>();
String line = "";
while ((line = reader.readLine()) != null) {
//split string and construct Data object and add it to dataList 
dataList.add(parse(line));
}
reader.close();
Collections.sort(dataList);
writers = new FileWriter("final.txt");
for (Data d : dataList) {
writers.write(d.toString());
writers.write("rn");
}
writers.close();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
}

代码中的输入/输出:

input: mamy, 30, new, old
daddy, 21, new, new
output: daddy, 21,new,new
mamy , 30, new, old

预期输出:

daddy,21,new
mamy,30,new,old

我的问题是如何在存储到final.txt之前删除重复数组?任何建议吗?

Answer 1

我认为Set非常适合你，它消除了重复。

Set<Data> dataSet = new HashSet<>(dataList);

Answer 2

要删除duplicates，请在sorting之前使用此代码。

ArrayList<Data> newDataList = new ArrayList<>(); 
for (Data element : dataList) { 
if (!newDataList.contains(element)) { 
newDataList.add(element); 
} 
}  
dataList = newDataList;