I have a problem with the stream of Java 8 foreach attempting to move on next item in loop. I cannot set the command like continue;
, only return;
works but you will exit from the loop in this case. I need to move on next item in loop. How can I do that?
Example(not working):
try(Stream<String> lines = Files.lines(path, StandardCharsets.ISO_8859_1)){
filteredLines = lines.filter(...).foreach(line -> {
...
if(...)
continue; // this command doesn't working here
});
}
Example(working):
try(Stream<String> lines = Files.lines(path, StandardCharsets.ISO_8859_1)){
filteredLines = lines.filter(...).collect(Collectors.toList());
}
for(String filteredLine : filteredLines){
...
if(...)
continue; // it's working!
}
The lambda you are passing to forEach()
is evaluated for each element received from the stream. The iteration itself is not visible from within the scope of the lambda, so you cannot continue
it as if forEach()
were a C preprocessor macro. Instead, you can conditionally skip the rest of the statements in it.
Another solution: go through a filter with your inverted conditions : Example :
if(subscribtion.isOnce() && subscribtion.isCalled()){
continue;
}
can be replaced with
.filter(s -> !(s.isOnce() && s.isCalled()))
The most straightforward approach seem to be using "return;" though.
You can use a simple if
statement instead of continue. So instead of the way you have your code, you can try:
try(Stream<String> lines = Files.lines(path, StandardCharsets.ISO_8859_1)){
filteredLines = lines.filter(...).foreach(line -> {
...
if(!...) {
// Code you want to run
}
// Once the code runs, it will continue anyway
});
}
The predicate in the if statement will just be the opposite of the predicate in your if(pred) continue;
statement, so just use !
(logical not).
Source: Stackoverflow.com