[英]Setting values in an ArrayList with multiple objects
如果我理解正確的話,你有一個List<>
對象,你想在這些對象上進行計算。 這可以通過 Streams 輕松完成。
MyObject object1 = new MyObject(new Date(), "", "", null);
MyObject object2 = new MyObject(new Date(), "", "", null);
// for example purposes, I'm creating a List<> with two objects in it
List<MyObject> myList = new ArrayList<>();
myList.add(object1);
myList.add(object2);
myList = myList.stream()
.map(myObject -> {
String result = "do some computations which result in a value to set";
myObject.setTest(result);
return myObject;
})
.collect(Collectors.toList());
// if you were to look into your objects, you'll see that the null-value is replaced
private class MyObject {
private Date date;
private String vwapspy;
private String vwapgdx;
private String test;
// constructor
// getters and setters
}
您的主要目標是更新您的變量。 在 Stream 的.map()
函數中,您可以輕松放置所需的任何邏輯。
當然,Streams 只從 Java 8 開始可用。示例中的邏輯也可以通過簡單的循環來完成。 如果我沒有清楚地解決您的用例,請查看一些教程。
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