intellij-idea

问题 For some unknown reason, in every class where I have methods that return String type or accept String as a parameter, intellij is automatically importing: import com.sun.org.apache.xpath.internal.operations.String; Instead of java.lang.String Is this a known Bug or is there a way to disable this? 回答1: You can exclude classes from import and completion under File | Settings | Editor | General | Auto Import . Check if java.lang.String is not added there by accident. And you can add com.sun.org

问题 trying to implement Kleisli category for a made-up Partial type in Scala (reading Bartosz Milewski's "category theory for programmers", that's exersize for chapter 4) object Kleisli { type Partial[A, B] = A => Option[B] implicit class KleisliOps[A, B](f1: Partial[A, B]) { def >=>[C](f2: Partial[B, C]): Partial[A, C] = (x: A) => for { y <- f1(x) z <- f2(y) } yield z def identity(f: Partial[A, B]): Partial[A, B] = x => f(x) } val safeRecip: Partial[Double, Double] = { case 0d => None case x =>

问题 trying to implement Kleisli category for a made-up Partial type in Scala (reading Bartosz Milewski's "category theory for programmers", that's exersize for chapter 4) object Kleisli { type Partial[A, B] = A => Option[B] implicit class KleisliOps[A, B](f1: Partial[A, B]) { def >=>[C](f2: Partial[B, C]): Partial[A, C] = (x: A) => for { y <- f1(x) z <- f2(y) } yield z def identity(f: Partial[A, B]): Partial[A, B] = x => f(x) } val safeRecip: Partial[Double, Double] = { case 0d => None case x =>

问题 trying to implement Kleisli category for a made-up Partial type in Scala (reading Bartosz Milewski's "category theory for programmers", that's exersize for chapter 4) object Kleisli { type Partial[A, B] = A => Option[B] implicit class KleisliOps[A, B](f1: Partial[A, B]) { def >=>[C](f2: Partial[B, C]): Partial[A, C] = (x: A) => for { y <- f1(x) z <- f2(y) } yield z def identity(f: Partial[A, B]): Partial[A, B] = x => f(x) } val safeRecip: Partial[Double, Double] = { case 0d => None case x =>

问题 trying to implement Kleisli category for a made-up Partial type in Scala (reading Bartosz Milewski's "category theory for programmers", that's exersize for chapter 4) object Kleisli { type Partial[A, B] = A => Option[B] implicit class KleisliOps[A, B](f1: Partial[A, B]) { def >=>[C](f2: Partial[B, C]): Partial[A, C] = (x: A) => for { y <- f1(x) z <- f2(y) } yield z def identity(f: Partial[A, B]): Partial[A, B] = x => f(x) } val safeRecip: Partial[Double, Double] = { case 0d => None case x =>

问题 So im running my program and I need to setup @NotNull from import javaz.validation.constraints.NotBlank; All there is @NonNull private final String firstName; and import org.springframework.lang.NonNull; How do I install @NotNull or is @NonNull the same thing? 回答1: This should answer your question. Short answer: there is a subtle difference, but it all depends on what you want, so you either need to read the post I've linked above or tell us more information. 来源： https://stackoverflow.com

问题 So im running my program and I need to setup @NotNull from import javaz.validation.constraints.NotBlank; All there is @NonNull private final String firstName; and import org.springframework.lang.NonNull; How do I install @NotNull or is @NonNull the same thing? 回答1: This should answer your question. Short answer: there is a subtle difference, but it all depends on what you want, so you either need to read the post I've linked above or tell us more information. 来源： https://stackoverflow.com

问题 I have this a test that I run under @RunWith(SpringRunner.class) @SpringBootTest @Test public void testFind() throws IOException { Review<Hostel> hostelByComplaintId = hostelService.findByComplaintId(complaintId).orElse(null); assertThat(hostelByComplaintId).isNotNull(); } when I run the test from the command line mvn test I got this error Failed tests: Expecting actual not to be null but when I run it from IntelliJ IDEA, the test does not fail 回答1: You can just write complete command if

问题 I have this a test that I run under @RunWith(SpringRunner.class) @SpringBootTest @Test public void testFind() throws IOException { Review<Hostel> hostelByComplaintId = hostelService.findByComplaintId(complaintId).orElse(null); assertThat(hostelByComplaintId).isNotNull(); } when I run the test from the command line mvn test I got this error Failed tests: Expecting actual not to be null but when I run it from IntelliJ IDEA, the test does not fail 回答1: You can just write complete command if

问题 I am trying to learning Scala with Spark. I am following a tutorial but I am having an error, when I try to import the library dependencies of Spark : libraryDependencies += "org.apache.spark" %% "spark-core" % "2.4.3" I am getting the following error : And I have 3 Unkwons artifacts. What could be the problem here? My code is so simple, it is just a Hello World. 回答1: Probably you need to add to your build.sbt : resolvers += "spark-core" at "https://mvnrepository.com/artifact/org.apache.spark