Java Generic Supplier - 来自现有方法

Question

我想实现这样的目标。

public class Test1 {
 dummyResponseForTest for any type.
    public static <T> DummyResponse<T> dummyResponseForTest(String data) {
        return new DummyResponse(data);
    }

//doesn't compile
   public static <U> Supplier<U> responseSupplier = () -> dummyResponseForTest("test");

   String stringResponse = responseSupplier.<String>get();
   Integer stringResponse = responseSupplier.<Integer>get();
}

不编译

public static <U> Supplier<U> responseSupplier = () -> Test2.<U>dummyResponseForTest("test");`

Answer 1

字段不能有自己的类型变量，只有类和方法可以。

您可以改用一种方法：

public static <U> Supplier<U> responseSupplier() {
    return () -> dummyResponseForTest("test");
}