为什么我的JAVA项目中不能实现Streams功能？

Question

I'm a beginner of JAVA programming. Recently, I tried to use the map & filter functionality of Stream s like the following code shows.

    List<String> strList = Arrays.asList("abc", "", "bcd", "", "defg", "jk");
    long count = strList.stream().filter(x -> x.isEmpty()).count();
    System.out.printf("List %s has %d empty strings %n", strList, count);

However, the compiler always complains that I need to "Create local variable x".

Maybe I lose some basic steps that is too easy to find any related discussions on Google.

My JAVA compiler version is J2SE 1.5, and I import java.util.stream.* to my file.

Thanks!

Answer 1

Stream s and lambda expressions are Java 8 functionality. Upgrade your compiler.