You are asking the wrong question. You are asking about sequential vs. parallel whereas you want to process items in order, so you have to ask about ordering. If you have an ordered stream and perform operations which guarantee to maintain the order, it doesn’t matter whether the stream is processed in parallel or sequential; … Read more
Although adding a default method with the same name in the two interfaces would make the code fail to compile, but once you resolve the compilation error, the binaries obtained after compiling both the interfaces, and the class implementing the interfaces, would be backward compatible. So, the compatibility is really about binary compatibility. This is … Read more
A bit of conjecture here. It is possible for an object to be finalized and garbage collected even if there are references to it in local variables on the stack, and even if there is an active call to an instance method of that object on the stack! The requirement is that the object be … Read more
With JPA 2.2, you no longer need to use converter it added support for the mapping of the following java.time types: java.time.LocalDate java.time.LocalTime java.time.LocalDateTime java.time.OffsetTime java.time.OffsetDateTime @Column(columnDefinition = “DATE”) private LocalDate date; @Column(columnDefinition = “TIMESTAMP”) private LocalDateTime dateTime; @Column(columnDefinition = “TIME”) private LocalTime localTime;
You could use map() to get a Stream of region lists and then mapToInt to get the number of regions for each country. After that use sum() to get the sum of all the values in the IntStream: countries.stream().map(Country::getRegions) // now it’s a stream of regions .filter(rs -> rs != null) // remove regions lists … Read more
Because streams that require explicit resource release is actually a pretty unusual case. So we chose not to burden all stream execution with something that is only valuable for .01% of usages. We made Stream Autocloseable so that you can release resources from the source if you want to, but this is where we stopped, … Read more
You have many options. Already noted: boolean isEqual = maybeFoo.equals(Optional.of(testFoo)); Alternatively: boolean isEqual = maybeFoo.isPresent() && maybeFoo.get().equals(testFoo); Or: boolean isEqual = testFoo.equals(maybeFoo.orElse(null)); These last two do have slightly different semantics: each returns a different value when maybeFoo is empty and testFoo is null. It’s not clear which is the correct response (which I guess is … Read more
You have not actually transformed the list; you have created a new list. To transform the list in one small method call, use List#replaceAll(): list.replaceAll(String::toUpperCase);
Homebrew does not support OpenJDK@8 on Apple Silicon (M1/M2) but Zulu Community 8 is present as a cask. You just have to enable cask-versions repository and install zulu8 cask. brew tap homebrew/cask-versions brew install –cask zulu8 It will install the JDK in /Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home. You should then configure your JAVA_HOME variable for development tools to use … Read more
Primitive optionals haven’t map, flatMap and filter methods by design. Moreover, according to Java8 in Action p.305 you shouldn’t use them. The justification of use primitive on streams are the performance reasons. In case of huge number of elements, boxing/unboxing overhead is significant. But this is senselessly since there is only one element in Optional. … Read more