I have the following code:
package test;
import java.util.stream.IntStream;
public class A {
public static void main(String[] args) {
IntStream.range(0, 10).mapToObj(n -> new Object() {
int i = n;
}).mapToInt(o -> o.i).forEachOrdered(System.out::println);
}
}
This code works fine when compiled with javac 1.8.0_101, and produces the number 0 to 9 as expected.
But when I use this code in eclipse, it tells me that at o.i:
i cannot be resolved or is not a field
And producing an error when executing this:
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
i cannot be resolved or is not a field
at test.A.main(A.java:9)
Why do I need to use javac to compile this code?
And how do I get eclipse to behave?
Edit:
I did some tests and it works in ecj as long as I don't create the instance in a lambda:
package test;
import java.util.Optional;
import java.util.function.Supplier;
public class B {
public static void main(String[] args) {
// This works fine:
System.out.println(new Object() {
int j = 5;
}.j);
// This also
System.out.println(trace(new Object() {
int j = 5;
}).j);
// Also no problem
System.out.println(unwrapAndTrace(Optional.of(new Object() {
int j = 5;
})).j);
// Lambdas work:
System.out.println(((Supplier & Serializable) () -> new Object()).get());
// This doesn't work.
System.out.println(invokeAndTrace(() -> new Object() {
int j = 5;
}).j);
}
public static <T> T trace(T obj) {
System.out.println(obj);
return obj;
}
public static <T> T invokeAndTrace(Supplier<T> supplier) {
T result = supplier.get();
System.out.println(result);
return result;
}
public static <T> T unwrapAndTrace(Optional<T> optional) {
T result = optional.get();
System.out.println(result);
return result;
}
}
