lambda - What's the right way to check null or check exceptions in a chained statement in Java 8? -

for example code:

list<class> classes =          stream.of("java.lang.object", "java.lang.integer", "java.lang.string")               .map(classname -> class.forname(classname))               .collect(collectors.tolist()); 

this code runs fine now. but, assume have empty list in stream , have tons of operations stream. nullpointer exceptions , etc. find it's hard try-catch kind of statement. what's right way handle exception this?

you not need check nulls. if have empty stream operations skipped:

stream.of("hello")       .filter(e => "world".equals(e)) // empties stream       .foreach(system.out::println); // no nullpointer, no output 

exception handling possible in mapper:

    list<class<?>> classes = stream.of("java.lang.object", "java.lang.integer", "java.lang.string")             .map(classname -> {                 try {                     return class.forname(classname);                 } catch (exception e) {                     throw new yourruntimeexception();                 }             })             .collect(collectors.tolist()); 

if want exceptions ignored, suggest map optionals.

    list<class<?>> classes = stream.of("java.lang.object", "java.lang.integer", "java.lang.string")             .map(classname -> {                 try {                     return optional.of(class.forname(classname));                 } catch (exception e) {                     return optional.<class<?>>empty();                 }             })             .filter(optional::ispresent) // ignore empty values             .map (optional::get) // unwrap optional contents             .collect(collectors.tolist()); 

please have @ how can throw checked exceptions inside java 8 streams? more detailed discussion class.forname in combination java 8 streams.