Given this java 8 code
public Server send(String message) {
sessions.parallelStream()
.map(Session::getBasicRemote)
.forEach(basic -> {
try {
basic.sendText(message);
} catch (IOException e) {
e.printStackTrace();
}
});
return this;
}
how do we properly make this IOException
be delegated up the stack of the method call? (in nutshell how to make this method throw this IOException
?)
Lambdas in java does not look very friendly to error handling...
My approach would be to sneakily throw it from the lambda, but take care to have the send
method declare it in its throws
clause. Using the Exceptional
class I posted here:
public Server send(String message) throws IOException {
sessions.parallelStream()
.map(Session::getBasicRemote)
.forEach(basic -> Exceptional.from(() -> basic.sendText(message)).get());
return this;
}
This way you're effectively making the compiler "look away" for just a bit, disabling its exception checking at one spot in your code, but by declaring the exception on your send
method, you restore the regular behavior for all its callers.