假设我有一个使用lambda表达式(闭包)定义的对象列表.有没有办法检查它们,以便可以进行比较?
我最感兴趣的代码是
List<Strategy> strategies = getStrategies();
Strategy a = (Strategy) this::a;
if (strategies.contains(a)) { // ...
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完整的代码是
import java.util.Arrays;
import java.util.List;
public class ClosureEqualsMain {
interface Strategy {
void invoke(/*args*/);
default boolean equals(Object o) { // doesn't compile
return Closures.equals(this, o);
}
}
public void a() { }
public void b() { }
public void c() { }
public List<Strategy> getStrategies() {
return Arrays.asList(this::a, this::b, this::c);
}
private void testStrategies() {
List<Strategy> strategies = getStrategies();
System.out.println(strategies);
Strategy a = (Strategy) …
Run Code Online (Sandbox Code Playgroud) 我知道IdentityHashMap,但是我需要使用“ identitySet ”之类的东西(它使用等于-> o1 == o2)。当我用“ extractor”(JavaFX)收听Observable列表时,我将使用一个:
List<Person> deleteList = new ArrayList<>();
List<Person> addList = new ArrayList<>();
ObservableList<Person> list = FXCollections.observableArrayList(Person.extractor());
list.add(new Person("a",1));
list.add(new Person("b",2));
list.add(new Person("c",3));
list.addListener((ListChangeListener<Person>) observable -> {
if(observable.next()) {
if (observable.wasAdded()) {
addList.addAll(observable.getAddedSubList());
}
if (observable.wasUpdated()) {
deleteList.add(list.get(observable.getFrom()));
}
if (observable.wasRemoved()) {
deleteList.addAll(observable.getRemoved());
}
}
});
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人类:
public class Person {
private final StringProperty s;
private final DoubleProperty d;
//Getters and Setters
// ...
@Override
public int hashCode() {
int result = …
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