如何从Java中的另一个类导入已填充的现成ArrayList？

我正在处理大量导入的数据，并使用2类（WeatherStation，WeatherReading）在主要方法中检索其中的某些部分。数据是气象站负载（站号，名称，纬度，经度，年，时间，温度等）我制作了第三类（SoloSiteIds），其唯一目的是返回站点ID的完整且完整的ArrayList，而不重复。但是我不能将ArrayList从另一个类导入到我的main方法中。我的SoloSiteIds类如下所示：

public class SoloSiteIds {

 static ArrayList <Integer> siteIds = new ArrayList <Integer>();
 

 public SoloSiteIds() {
 }
 
 public SoloSiteIds( ArrayList <Integer> siteIds) {
     
     String[] weatherData = WeatherData.getData();{ // get the weather data 
     
         for (int i = 1; i < weatherData.length; i++) {
                String line = weatherData[i];
                String[] elements = line.split(","); // Split the data at ",
                
                String siteid = elements[0]; // convert all the site id's at index 0 to integers
                int id = Integer.parseInt(siteid);
                if(!siteIds.contains(id)) {
                    siteIds.add(id);
                }
     
     
     this.siteIds=siteIds;



         }
    
}
}

public static ArrayList<Integer> getSiteIds() {
    return siteIds;
}

public ArrayList<Integer> setSiteIds(ArrayList<Integer> siteIds) {
    return this.siteIds = siteIds;
}   

}

我尝试导入ArrayList“ siteIds”的主要方法如下：

        WeatherStation thisStation = new WeatherStation (id, name, lat, lon);
    WeatherReading thisReading = new WeatherReading(year, month, date, hour, windSpeed, temp);
    SoloSiteIds siteList= new SoloSiteIds();
    


    
    String[] weatherData = WeatherData.getData();{ // get the weather data

        
        for (int i = 1; i < weatherData.length; i++) {
            String line = weatherData[i];
            String[] elements = line.split(","); // Split the data at ","   
            
    
            
                

                    String siteid = elements[0]; // convert all the site id's at index 0 to integers
                    id = Integer.parseInt(siteid);
                    thisStation.setId(id);
                    
                    thisStation.setName(elements[1]);
                    
                    //parse the different elements into different data types
                    
                    String stringLat = elements[2];    
                    lat= Double.parseDouble(stringLat);
                    lat = thisStation.setLat(lat);
                    lat=thisStation.setLat(lat);
                        
                    String stringLon = elements[3];
                    lon= Double.parseDouble(stringLon);
                    lat = thisStation.setLon(lon);
                    lat=thisStation.setLon(lon);
                    
                    String stringTemp=elements[9];
                    temp=Double.parseDouble(stringTemp);
                    temp=thisReading.setTemp(temp);

仅顶部是相关的。我尝试使用“ thisList”实例和新的ArrayList来尝试.set和.get的许多不同变体

ArrayList<Integer> siteIds = thisList.setSiteIds();
ArrayList<Integer> siteIds= SoloSiteIds.getSiteIds();
thisList=Siteids.setSiteIds();
thisList=SingleSoloSites.setSiteIds();

等等等。这可能看起来很愚蠢，但我只是表明我已经尝试了很多事情，我被困了，谢谢