在 Object 中存儲值並將其轉換為 int

Question

我正在做一個來自 coursera 的作業，我正在為 map 進行編碼，它顯示標記以指出發生地震的地點。因此，如果地震發生在 2000 年之后，我想將標記的顏色更改為黃色，如果在 2000 年之前，我想將標記的顏色更改為灰色2000 年。在我的代碼中，我在 ArrayList 中使用 PointFeature 作為數據類型，它存儲了諸如年份之類的信息，以便標記改變顏色。我正在使用展開地圖。

 List<PointFeature> bigEqs = new ArrayList<PointFeature>();
 Location valLoc = new Location(-38.14f,-73.03f);   
 Feature valEq = new PointFeature(valLoc);
 bigEqs.add((PointFeature) valEq);
 valEq.addProperty("title", "Valvidivia,Chile");
 valEq.addProperty("magnitude","9.5");
 valEq.addProperty("date", "May 22,1960");
 valEq.addProperty("year", "1960");
      
 Location valLoc1 = new Location(60.59f,-147.848f);
 Feature alaskaEq = new PointFeature(valLoc1);
 bigEqs.add((PointFeature) alaskaEq);
 alaskaEq.addProperty("title", "Prince William Sound ,Southern Alaska");
 alaskaEq.addProperty("magnitude","9.2");
 alaskaEq.addProperty("date", "March 28,1964");
 alaskaEq.addProperty("year", "1964");
   
 Location valLoc2 = new Location(3.30f,95.98f);
 Feature sumantraEq = new PointFeature(valLoc2);
 bigEqs.add((PointFeature) sumantraEq);
 sumantraEq.addProperty("title", "Sumatra-Andaman Islands ");
 sumantraEq.addProperty("magnitude", " 9.1");
 sumantraEq.addProperty("date", " December 26,2004");
 sumantraEq.addProperty("year", " 2004");
   
   
 Location valLoc3 = new Location(38.30f,142.37f);
 Feature japanEq = new PointFeature(valLoc3);
 bigEqs.add((PointFeature) japanEq);
 japanEq.addProperty("title", "Tohuku(Eastern coast of Honshu) ,Japan");
 japanEq.addProperty("magnitude", " 9.1");
 japanEq.addProperty("date", "November 3 , 2011 ");
 japanEq.addProperty("year", "2011 ");
   
 Location valLoc4 = new Location(52.62f,159.78f);
 Feature kamchatkaEq = new PointFeature(valLoc4);
 bigEqs.add((PointFeature) kamchatkaEq);
 kamchatkaEq.addProperty("title", "Kamchatka,Russia ");
 kamchatkaEq.addProperty("magnitude", " 9.0");
 kamchatkaEq.addProperty("date", "April 24,1952 ");
 kamchatkaEq.addProperty("year", " 1952");
 
 List<Marker> markers1 = new ArrayList<Marker>();
 for(PointFeature eq:bigEqs) {
       markers1.add(new SimplePointMarker(eq.getLocation(),eq.getProperties()));
       
  }  for(Marker mk:markers1) {
     if(  mk.getProperty("year")>2000) {
         mk.setColor(color(255,255,0));
     }else {
         mk.setColor(color(128,128,128));
     }
     map.addMarker(mk);
 }

但它顯示錯誤：它不能在這里將 obj 轉換為 int，if( mk.getProperty("year")>2000)

Answer 1

由於年份是一個數字，因此如果將其解析為 int 它將起作用。

例子：

if(Integer.parseInt(mk.getProperty("year"))>2000)

這將起作用。