java Lambda expressions are not supported at this language level
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Lambda expressions are not supported at this language level
提问by Klausos Klausos
I have a Java class that uses Spark. I need to filter out the header from JavaRDD. This is how I want to do this.
I have a Java class that uses Spark. I need to filter out the header from JavaRDD. This is how I want to do this.
String first = data.first();
JavaRDD<String> filteredData = data.filter((String s) -> {return !s.contains(first);});
However, this code data.filter((String s) -> {return !s.contains(first);})cannot be compiled. IntelliJ IDE says "Lambda expressions are not supported at this language level".
However, this code data.filter((String s) -> {return !s.contains(first);})cannot be compiled. IntelliJ IDE says "Lambda expressions are not supported at this language level".
回答by pepyakin
You can use lambdas on Java 7, but it is a bit involved —?you have to use something like Retrolambda.
You can use lambdas on Java 7, but it is a bit involved —?you have to use something like Retrolambda.
Also you can do the same thing without lambdas. Lambdas can be easily represented via annonymous classes, however it is a lot more verbose.
Also you can do the same thing without lambdas. Lambdas can be easily represented via annonymous classes, however it is a lot more verbose.
final String first = data.first();
JavaRDD<String> filteredData = data.filter(new Function<String, Boolean>() {
@Override public Boolean call(String s) {
return !s.contains(first);
}
});
