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将java.lang.Boolean转换为Scala Boolean

refactoring scala java

Mr.Turtle · 技术社区 · 6 年前

我目前正在开发一个Scala应用程序,它利用Spring-Boot和Swagger发送&接听休息电话。

Swagger和springboot是纯Java项目,与Scala的兼容性有限,但我似乎找到了解决这个问题的方法。

关于我所做的:

case class ParamsAsJava(includeMovies: java.lang.Boolean = java.lang.Boolean.FALSE, includeTvShows: java.lang.Boolean = java.lang.Boolean.FALSE) {

  def toScala(): Params = {
    Params(
      includeMovies = convertToScala(includeMovies),
      includeTvShows = convertToScala(includeTvShows)
    )
  }

  private def convertToScala(test: java.lang.Boolean): Boolean
  = if (test == null) false else test.booleanValue

}

case class Params(includeMovies: Boolean = false, includeTvShows: Boolean = false)

object Application extends App {

  val test1 = ParamsAsJava(java.lang.Boolean.FALSE, java.lang.Boolean.TRUE).toScala
  val test2 = ParamsAsJava(java.lang.Boolean.TRUE, java.lang.Boolean.TRUE).toScala
  val test3 = ParamsAsJava().toScala
  val test4 = ParamsAsJava(null, null).toScala
  val test5 = ParamsAsJava(null, java.lang.Boolean.TRUE).toScala

  println(s"Test 1 = $test1")
  println(s"Test 2 = $test2")
  println(s"Test 3 = $test3")
  println(s"Test 4 = $test4")
  println(s"Test 5 = $test5")
}

输出

测试1=参数(假,真)

测试3=参数(假,假)

测试5=参数(假,真)

好啊。。。我的问题是:

有更简单的方法吗&更具可读性的实现方法? 令人惊叹的

2 回复 | 直到 6 年前

Andrey Tyukin 6 年前

你不需要写出来 java.lang.blah 每次进来

ParamsAsJava(java.lang.Boolean.FALSE, java.lang.Boolean.TRUE)

ParamsAsJava(false, true)

摆脱 toScala ,在中定义隐式转换 Params 伴奏对象:
```
object Params {
  implicit def params_j2s(p: ParamsAsJava): Params = p.toScala()
}
```
现在你可以写:
```
val test1: Params = ParamsAsJava(true, false)
```
当然,如果您不是在真空中定义这个变量,而是将它传递给一个方法,那么将自动推断正确的类型,并且隐式地转换对象。
不需要使用parens () def toScala() 方法无副作用。

prayagupa soxunyi 6 年前

或者你可以告诉Spring使用 ScalaObjectMapper

<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-scala_2.12</artifactId>
    <version>2.9.7</version>
</dependency>

WebMvcConfigurerAdapter . 例子;

import com.fasterxml.jackson.module.scala.DefaultScalaModule
import com.fasterxml.jackson.module.scala.experimental.ScalaObjectMapper
import scala.collection.JavaConverters._

@EnableWebMvc
@Configuration
@PropertySource(Array("classpath:config/default.properties"))
@ComponentScan(Array(
  "com.prayagupd"
))
@Order(HIGHEST_PRECEDENCE)
class MyAppConfig extends WebMvcConfigurerAdapter {

  override def extendMessageConverters(converters: java.util.List[HttpMessageConverter[_]]): Unit = {
    val encodeDecoderOpt = converters.asScala.collectFirst { case p: MappingJackson2HttpMessageConverter => p }

    val jacksonConverter = encodeDecoderOpt.getOrElse(new MappingJackson2HttpMessageConverter)
    jacksonConverter.setObjectMapper(Config.objectMapper)

    if (encodeDecoderOpt.isEmpty) // because converters is mutable
       converters.add(jacksonConverter)
  }
}


object Config {

  @Bean
  def objectMapper: ObjectMapper = {
    new ObjectMapper() with ScalaObjectMapper
  }.registerModule(DefaultScalaModule)
}

@RestController
@CrossOrigin(origins = Array("*"))
@RequestMapping(value = Array("/"))
class MyController @Autowired()(implicit val jacksonObjectMapper: ObjectMapper) {
  import MyController._

  @Async
  @RequestMapping(value = Array("/talk"), method = Array(RequestMethod.POST), consumes = Array(MediaType.APPLICATION_JSON_VALUE), produces = Array(MediaType.APPLICATION_JSON_VALUE))
  def talk(@RequestBody request: MyRequest): MyResponse = {
       // goes here
   }
}

//expose these in client jar if you want
object MyController {
  final case class MyRequest(includeMovies: Boolean, includeTvShows: Boolean, somethingElse: List[String])

  final case class MyResponse(whatever: String)
}

Karthik P 5 年前

我用的是scala.Boolean box 和 unbox 方法。