java如何从lambda中获取变量？

Question

我有一个在文件中查找动物物种的方法，我希望它在数据库中不存在物种时抛出一个错误

public void printAnimalFromNames(String... s){
        try (Stream<String> stream = Arrays.stream(s)) {
            stream.forEach(x -> printAnimalPage(AnimalInfo.get(findSpecie(x))));
        } catch (Exception e){
            System.out.println("this spiece don't seem to exist");
        }
    }

在我的catch部分，我想在错误解释中加入x变量，比如

[...]
catch (Exception e){
            System.out.println("this spiece "+x+" don't seem to exist");
        }

我该怎么办

Answer 1

您必须将try-catch移动到lambda的主体内，因为lambda参数x在这个范围内：

public void printAnimalFromNames(String... s) {
    try (Stream<String> stream = Arrays.stream(s)) {
        stream.forEach(x -> {
            try {
                printAnimalPage(AnimalInfo.get(findSpecie(x)));
            } catch (Exception e) {
                System.out.println("this specie " + x + " don't seem to exist");
            }
        });
    }
}