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Using streams for a null-safe conversion from an array to list
Converting Array to ListCreate ArrayList from arrayHow to simplify a null-safe compareTo() implementation?Converting array to list in JavaConvert list to array in JavaRetrieving a List from a java.util.stream.Stream in Java 8How to Convert a Java 8 Stream to an Array?Java 8 Stream and operation on arraysHow can I create a stream from an array?How to sum a list of integers with java streams?Java 8 stream - how to properly make NPE-safe stream
I'm looking for a succinct way to rewrite a piece of Java code so that it uses streams to convert an array to a list in a null-safe fashion. Here's the original code:
public MailObject toMailObject(final String[] ccAddresses)
final MailObject mailObject = new MailObject();
// line of code to be altered
mailObject.setCcAddresses(ccAddresses == null
? Collections.emptyList() : Arrays.asList(ccAddresses));
// other necessary code
return mailObject;
I've thought of doing something like this:
// psuedocode that obviously doesn't compile
Optional.ofNullable(ccAddresses).SOMETHING.orElse(Collections.emptyList());
where SOMETHING would be along the lines of:
Arrays.stream(ints).collect(Collectors.toList());
but I can't seem to get the syntax quite right.
This question was helpful but didn't exactly address my issue. Could anyone point me in the right direction? I feel like I'm close...
Thank you very much for your time.
java java-stream
asked Mar 21 at 1:31
risingTiderisingTide
62041238
add a comment |
I'm looking for a succinct way to rewrite a piece of Java code so that it uses streams to convert an array to a list in a null-safe fashion. Here's the original code:
public MailObject toMailObject(final String[] ccAddresses)
final MailObject mailObject = new MailObject();
// line of code to be altered
mailObject.setCcAddresses(ccAddresses == null
? Collections.emptyList() : Arrays.asList(ccAddresses));
// other necessary code
return mailObject;
I've thought of doing something like this:
// psuedocode that obviously doesn't compile
Optional.ofNullable(ccAddresses).SOMETHING.orElse(Collections.emptyList());
where SOMETHING would be along the lines of:
Arrays.stream(ints).collect(Collectors.toList());
but I can't seem to get the syntax quite right.
This question was helpful but didn't exactly address my issue. Could anyone point me in the right direction? I feel like I'm close...
Thank you very much for your time.
java java-stream
asked Mar 21 at 1:31
risingTiderisingTide
62041238
5
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
1
.map(Arrays::asList)
– shmosel
Mar 21 at 2:05
add a comment |
I'm looking for a succinct way to rewrite a piece of Java code so that it uses streams to convert an array to a list in a null-safe fashion. Here's the original code:
public MailObject toMailObject(final String[] ccAddresses)
final MailObject mailObject = new MailObject();
// line of code to be altered
mailObject.setCcAddresses(ccAddresses == null
? Collections.emptyList() : Arrays.asList(ccAddresses));
// other necessary code
return mailObject;
I've thought of doing something like this:
// psuedocode that obviously doesn't compile
Optional.ofNullable(ccAddresses).SOMETHING.orElse(Collections.emptyList());
where SOMETHING would be along the lines of:
Arrays.stream(ints).collect(Collectors.toList());
but I can't seem to get the syntax quite right.
This question was helpful but didn't exactly address my issue. Could anyone point me in the right direction? I feel like I'm close...
Thank you very much for your time.
java java-stream
asked Mar 21 at 1:31
risingTiderisingTide
62041238
I'm looking for a succinct way to rewrite a piece of Java code so that it uses streams to convert an array to a list in a null-safe fashion. Here's the original code:
public MailObject toMailObject(final String[] ccAddresses)
final MailObject mailObject = new MailObject();
// line of code to be altered
mailObject.setCcAddresses(ccAddresses == null
? Collections.emptyList() : Arrays.asList(ccAddresses));
// other necessary code
return mailObject;
I've thought of doing something like this:
// psuedocode that obviously doesn't compile
Optional.ofNullable(ccAddresses).SOMETHING.orElse(Collections.emptyList());
where SOMETHING would be along the lines of:
Arrays.stream(ints).collect(Collectors.toList());
but I can't seem to get the syntax quite right.
This question was helpful but didn't exactly address my issue. Could anyone point me in the right direction? I feel like I'm close...
Thank you very much for your time.
java java-stream
java java-stream
asked Mar 21 at 1:31
risingTiderisingTide
62041238
asked Mar 21 at 1:31
risingTiderisingTide
62041238
edited Mar 21 at 3:01
risingTide
asked Mar 21 at 1:31
risingTiderisingTide
62041238
asked Mar 21 at 1:31
risingTiderisingTide
62041238
asked Mar 21 at 1:31
risingTiderisingTide
62041238
62041238
5
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
1
.map(Arrays::asList)
– shmosel
Mar 21 at 2:05
add a comment |
5
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
1
.map(Arrays::asList)
– shmosel
Mar 21 at 2:05
5
5
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
1
1
.map(Arrays::asList)– shmosel
Mar 21 at 2:05
.map(Arrays::asList)– shmosel
Mar 21 at 2:05
add a comment |
2 Answers
2
active
oldest
votes
In my opinion, the code that you have so far is perfectly readable. I think using a Stream for something like this will just complicate things. If you still want to use a Stream, then something like the following would work:
mailObject.setCcAddresses(Stream.ofNullable(ccAddresses)
.flatMap(Arrays::stream)
.collect(Collectors.toUnmodifiableList()));
As you can see, this is a more unreadable, and I wouldn't recommend it over your simple ternary expression.
Your Optional solution is slightly more readable and would look like the following:
mailObject.setCcAddresses(Optional.ofNullable(ccAddresses)
.map(Arrays::asList)
.orElse(Collections.emptyList()));
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
5
Stream.ofNullablerequires Java 9 andCollectors.toUnmodifiableList()even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code tomailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of usingOptionalorStreamhere even more.
– Holger
Mar 21 at 9:16
1
Good insight onto the Java versions that the first solution uses...and also into theList.of()possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!
– risingTide
Mar 21 at 18:18
add a comment |
You might use the map :
List<String> ccAddrs = Optional.ofNullable(ccAddress)
.map(Arrays::asList)
.orElse(Collections.emptyList())
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
I had wondered if the.map()method might be of use; thanks for the full usage in context.
– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
In my opinion, the code that you have so far is perfectly readable. I think using a Stream for something like this will just complicate things. If you still want to use a Stream, then something like the following would work:
mailObject.setCcAddresses(Stream.ofNullable(ccAddresses)
.flatMap(Arrays::stream)
.collect(Collectors.toUnmodifiableList()));
As you can see, this is a more unreadable, and I wouldn't recommend it over your simple ternary expression.
Your Optional solution is slightly more readable and would look like the following:
mailObject.setCcAddresses(Optional.ofNullable(ccAddresses)
.map(Arrays::asList)
.orElse(Collections.emptyList()));
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
5
Stream.ofNullablerequires Java 9 andCollectors.toUnmodifiableList()even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code tomailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of usingOptionalorStreamhere even more.
– Holger
Mar 21 at 9:16
1
Good insight onto the Java versions that the first solution uses...and also into theList.of()possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!
– risingTide
Mar 21 at 18:18
add a comment |
In my opinion, the code that you have so far is perfectly readable. I think using a Stream for something like this will just complicate things. If you still want to use a Stream, then something like the following would work:
mailObject.setCcAddresses(Stream.ofNullable(ccAddresses)
.flatMap(Arrays::stream)
.collect(Collectors.toUnmodifiableList()));
As you can see, this is a more unreadable, and I wouldn't recommend it over your simple ternary expression.
Your Optional solution is slightly more readable and would look like the following:
mailObject.setCcAddresses(Optional.ofNullable(ccAddresses)
.map(Arrays::asList)
.orElse(Collections.emptyList()));
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
5
Stream.ofNullablerequires Java 9 andCollectors.toUnmodifiableList()even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code tomailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of usingOptionalorStreamhere even more.
– Holger
Mar 21 at 9:16
1
Good insight onto the Java versions that the first solution uses...and also into theList.of()possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!
– risingTide
Mar 21 at 18:18
add a comment |
In my opinion, the code that you have so far is perfectly readable. I think using a Stream for something like this will just complicate things. If you still want to use a Stream, then something like the following would work:
mailObject.setCcAddresses(Stream.ofNullable(ccAddresses)
.flatMap(Arrays::stream)
.collect(Collectors.toUnmodifiableList()));
As you can see, this is a more unreadable, and I wouldn't recommend it over your simple ternary expression.
Your Optional solution is slightly more readable and would look like the following:
mailObject.setCcAddresses(Optional.ofNullable(ccAddresses)
.map(Arrays::asList)
.orElse(Collections.emptyList()));
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
In my opinion, the code that you have so far is perfectly readable. I think using a Stream for something like this will just complicate things. If you still want to use a Stream, then something like the following would work:
mailObject.setCcAddresses(Stream.ofNullable(ccAddresses)
.flatMap(Arrays::stream)
.collect(Collectors.toUnmodifiableList()));
As you can see, this is a more unreadable, and I wouldn't recommend it over your simple ternary expression.
Your Optional solution is slightly more readable and would look like the following:
mailObject.setCcAddresses(Optional.ofNullable(ccAddresses)
.map(Arrays::asList)
.orElse(Collections.emptyList()));
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
edited Mar 21 at 2:05
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
answered Mar 21 at 2:00
Jacob G.Jacob G.
16.4k52464
16.4k52464
5
Stream.ofNullablerequires Java 9 andCollectors.toUnmodifiableList()even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code tomailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of usingOptionalorStreamhere even more.
– Holger
Mar 21 at 9:16
1
Good insight onto the Java versions that the first solution uses...and also into theList.of()possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!
– risingTide
Mar 21 at 18:18
add a comment |
5
Stream.ofNullablerequires Java 9 andCollectors.toUnmodifiableList()even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code tomailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of usingOptionalorStreamhere even more.
– Holger
Mar 21 at 9:16
1
Good insight onto the Java versions that the first solution uses...and also into theList.of()possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!
– risingTide
Mar 21 at 18:18
5
5
Stream.ofNullable requires Java 9 and Collectors.toUnmodifiableList() even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code to mailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of using Optional or Stream here even more.– Holger
Mar 21 at 9:16
Stream.ofNullable requires Java 9 and Collectors.toUnmodifiableList() even requires Java 10. And when you’re using Java 9 or newer, you can likewise change the original code to mailObject.setCcAddresses(ccAddresses == null? List.of(): List.of(ccAddresses));, whose simplicity will highlight the silliness of using Optional or Stream here even more.– Holger
Mar 21 at 9:16
1
1
Good insight onto the Java versions that the first solution uses...and also into the
List.of() possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!– risingTide
Mar 21 at 18:18
Good insight onto the Java versions that the first solution uses...and also into the
List.of() possibility! Between this and the full answer by @Jacob G. there are a lot of options here; thanks!– risingTide
Mar 21 at 18:18
add a comment |
You might use the map :
List<String> ccAddrs = Optional.ofNullable(ccAddress)
.map(Arrays::asList)
.orElse(Collections.emptyList())
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
I had wondered if the.map()method might be of use; thanks for the full usage in context.
– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
add a comment |
You might use the map :
List<String> ccAddrs = Optional.ofNullable(ccAddress)
.map(Arrays::asList)
.orElse(Collections.emptyList())
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
I had wondered if the.map()method might be of use; thanks for the full usage in context.
– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
add a comment |
You might use the map :
List<String> ccAddrs = Optional.ofNullable(ccAddress)
.map(Arrays::asList)
.orElse(Collections.emptyList())
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
You might use the map :
List<String> ccAddrs = Optional.ofNullable(ccAddress)
.map(Arrays::asList)
.orElse(Collections.emptyList())
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
answered Mar 21 at 2:06
Mạnh Quyết NguyễnMạnh Quyết Nguyễn
11k1930
11k1930
I had wondered if the.map()method might be of use; thanks for the full usage in context.
– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
add a comment |
I had wondered if the.map()method might be of use; thanks for the full usage in context.
– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
I had wondered if the
.map() method might be of use; thanks for the full usage in context.– risingTide
Mar 21 at 18:23
I had wondered if the
.map() method might be of use; thanks for the full usage in context.– risingTide
Mar 21 at 18:23
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
@risingTide you're welcome. :D
– Mạnh Quyết Nguyễn
Mar 22 at 1:48
add a comment |
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5
Your original code seems succinct enough
– GBlodgett
Mar 21 at 1:35
Fair enough, but I'm curious as to the best way it can be done using streams.
– risingTide
Mar 21 at 1:36
1
.map(Arrays::asList)– shmosel
Mar 21 at 2:05