我實現了一個名為 EventSet 的類，其中包含一個帶有自定義比較器的 TreeSet。comparator 應該與 equals 一致，因為在將元素添加到集合之前，TreeSet 似乎使用 compare 或 compareTo 進行所有需要的比較。我的應用程序需要讀取包含一系列命令的文本文件，一個可能的命令是導入指定事件的文本文件。因此，一個假設的 event.txt 文件包含幾行，例如“IN LOGIN 18082019 ab001 45.457, 9,181 A”，應用程序調用一個方法來解析字符串并將其轉換為一個 Event 對象，該對象被添加到 EventSet 實例中。這里的問題很奇怪：一切正常，除非在命令文件中我嘗試導入相同的事件。txt 文件兩次，文件的第一行被轉換為一個事件，并作為重復項插入到集合中，即使 equals 和 compare 說它是重復項。無論我如何更改它，這只會發生在文件的第一行。到目前為止，這是我的一些代碼：類事件集：private static EventSet instance;private TreeSet<Event> eventTree;//costruttoreprivate EventSet() { EventComparator comp = new EventComparator(); this.eventTree = new TreeSet<Event>(comp);}public static EventSet getInstance() { if (instance == null) { instance = new EventSet(); } return instance;}public TreeSet<Event> getEventTree() { return eventTree;}public void setEventTree(TreeSet<Event> eventTree) { this.eventTree = eventTree;}public boolean add(Event e) { return this.eventTree.add(e);}public boolean add(Set<Event> set) { return this.eventTree.addAll(set);}類事件比較器：public EventComparator() { super();}@Overridepublic int compare(Event e1, Event e2) { if(e1.equals(e2)) { return 0; } else if(e1.getTimestamp().compareTo(e2.getTimestamp())>=0) { return 1; } else { return -1; }}
1 回答
紅糖糍粑
TA貢獻1815條經驗 獲得超6個贊
已解決：顯然，問題是由調用一個方法引起的，該方法讀取文件并在另一個從文件讀取的方法中對樹執行 add() 。我編輯了 import_events() 和 import_cmd() 方法，現在一切正常。
private HashSet<Event> import_events(String path) throws FileNotFoundException, IOException, ParseException {
FileReader fr1;
BufferedReader br1;
String current;
String[] tokens;
HashSet<Event> set = new HashSet<Event>();
fr1 = new FileReader(path);
br1 = new BufferedReader(fr1);
current = br1.readLine();
if (current == null) {
if (this.controller != null) {
controller.get_message("Warning: event file is empty, no events to import");
}
br1.close();
fr1.close();
return set;
}
InputLine il;
while (current != null) {
current = current.trim();
if (this.controller != null) {
il = new InputLine(current, controller);
} else {
il = new InputLine(current);
}
if (il.line_ok()) {
tokens = current.split(Pattern.quote(" "));
RegState reg_state = RegState.valueOf(tokens[0]);
String user_id = tokens[3];
LogState log_state = LogState.valueOf(tokens[1]);
InputLine.d_format.setLenient(false);
Date timestamp = InputLine.d_format.parse(tokens[2]);
String[] latlong = tokens[4].split(",");
double lat = Double.parseDouble(latlong[0]);
double longi = Double.parseDouble(latlong[1]);
Position pos = Position.create(lat, longi);
if (pos == null) {
if (this.controller != null) {
controller.get_message("Error: invalid coordinates at "+current+", event ignored");
}
break;
}
Emotion emotion = Emotion.valueOf(tokens[5]);
Event event = new Event(reg_state,log_state, timestamp, user_id, pos, emotion);
set.add(event);
}
current = br1.readLine();
}
br1.close();
fr1.close();
return set;
}
現在 import_events() 返回文件中包含的事件的 HashSet。
import_cmd() 使用 HashSet 作為在樹上調用 addAll() 的參數。
void import_cmd() throws NumberFormatException, ParseException {
FileReader fr;
BufferedReader br;
String current;
try {
fr = new FileReader(cmd_path);
br = new BufferedReader(fr);
} catch (FileNotFoundException e) {
if (this.controller != null) {
controller.get_message("Error: file not found at this location "+cmd_path.getAbsolutePath());
}
return;
}
InputLine line;
Set<Event> toAdd=new HashSet<Event>();
try {
current = br.readLine();
while (current != null) {
if (this.controller != null) {
line = new InputLine(current, controller);
} else {
line = new InputLine(current);
}
if (line.cmd_check() == 1) {
String extracted = line.getIn_line().substring(line.getIn_line().indexOf("(")+1, line.getIn_line().indexOf(")"));
String path = this.event_path.getAbsolutePath()+File.separator+extracted;
try {
toAdd=import_events(path);
if (this.controller != null) {
controller.get_message("File "+ extracted + " successfully imported ");
}
} catch (FileNotFoundException e) {
if (this.controller != null) {
controller.get_message("Error: file not found at "+path);
}
} catch (IOException ioe) {
if (this.controller != null) {
controller.get_message("Error: unable to read from file at "+path);
}
}
boolean addOk=EventSet.getInstance().add(toAdd);
if (this.controller!=null) {
if (addOk) {
controller.get_message("Events added");
} else {
controller.get_message("No events to add");
}
}
} else if (line.cmd_check() == 2) {
boolean valid = line.validate_date_iterval(line.getIn_line());
if (valid) {
Date[] dates = line.convertIntervaltoDates(line.intervalExtract(line.getIn_line()));
createmap(dates[0], dates[1]);
if (this.controller != null) {
controller.get_message("Map correctly created for "+ line.getIn_line());
}
} else if (this.controller != null) {
controller.get_message("Invalid date at "+ line.getIn_line()+": unable to create map");
}
}
current = br.readLine();
}
br.close();
fr.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
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