Question

我当前的hashmap如下所示：

val h1 = HashMap[String,Object]()
val h2 = ListBuffer[HashMap[String,String]]()
val h3 = HashMap[String,Object]()
val h4 = ListBuffer[HashMap[String,String]]()

基本上h1是我的主哈希，带有h2和h3以及其他字符串的键。 h3有h4和其他字符串的键。

因为scala不支持对字符串 - >对象类型的json进行散列，所以我看到我必须编写旧的写/读方法

如何编写写入和读取方法，以便检测内部地图，列表？

到目前为止，我一直在关注此事：Scala to JSON in Play Framework 2.1

来自迪马关于使用杰克逊的建议，在玩游戏时遇到错误

play.api.UnexpectedException: Unexpected exception[RuntimeException: java.lang.VerifyError: class com.fasterxml.jackson.module.scala.ser.ScalaIteratorSerializer overrides final method withResolved.(Lcom/fasterxml/jackson/databind/BeanProperty;Lcom/fasterxml/jackson/databind/jsontype/TypeSerializer;Lcom/fasterxml/jackson/databind/JsonSerializer;)Lcom/fasterxml/jackson/databind/ser/std/AsArraySerializerBase;]
at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:276)
at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:206)
at play.api.GlobalSettings$class.onError(GlobalSettings.scala:160)
at play.api.DefaultGlobal$.onError(GlobalSettings.scala:188)
at play.api.http.GlobalSettingsHttpErrorHandler.onServerError(HttpErrorHandler.scala:98)
at play.core.server.netty.PlayRequestHandler$$anonfun$2$$anonfun$apply$1.applyOrElse(PlayRequestHandler.scala:100)
at play.core.server.netty.PlayRequestHandler$$anonfun$2$$anonfun$apply$1.applyOrElse(PlayRequestHandler.scala:99)
at scala.concurrent.Future$$anonfun$recoverWith$1.apply(Future.scala:344)
at scala.concurrent.Future$$anonfun$recoverWith$1.apply(Future.scala:343)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)

Caused by: java.lang.RuntimeException: java.lang.VerifyError: class com.fasterxml.jackson.module.scala.ser.ScalaIteratorSerializer overrides final method withResolved.(Lcom/fasterxml/jackson/databind/BeanProperty;Lcom/fasterxml/jackson/databind/jsontype/TypeSerializer;Lcom/fasterxml/jackson/databind/JsonSerializer;)Lcom/fasterxml/jackson/databind/ser/std/AsArraySerializerBase;
at play.api.mvc.ActionBuilder$$anon$2.apply(Action.scala:463)
at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5$$anonfun$apply$6.apply(Action.scala:112)
at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5$$anonfun$apply$6.apply(Action.scala:112)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5.apply(Action.scala:111)
at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5.apply(Action.scala:110)
at scala.Option.map(Option.scala:146)
at play.api.mvc.Action$$anonfun$apply$2.apply(Action.scala:110)
at play.api.mvc.Action$$anonfun$apply$2.apply(Action.scala:103)
at scala.concurrent.Future$$anonfun$flatMap$1.apply(Future.scala:251)

Caused by: java.lang.VerifyError: class com.fasterxml.jackson.module.scala.ser.ScalaIteratorSerializer overrides final method withResolved.(Lcom/fasterxml/jackson/databind/BeanProperty;Lcom/fasterxml/jackson/databind/jsontype/TypeSerializer;Lcom/fasterxml/jackson/databind/JsonSerializer;)Lcom/fasterxml/jackson/databind/ser/std/AsArraySerializerBase;
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

我的依赖项：

libraryDependencies += "com.fasterxml.jackson.core" % "jackson-databind" % "2.4.4"
libraryDependencies += "com.fasterxml.jackson.module" %% "jackson-module-scala" % "2.5.1"

Answer 1

谁告诉你scala不支持它？有不同类型的库...例如，如果你使用杰克逊，你只需要做这样的事情：

 val mapper = new ObjectMapper()
   .registerModule(DefaultScalaModule)

 val h1 = mapper.readObject(input, classOf[Map[String,_]])

如何将嵌套的HashMap（使用哈希映射嵌套）转换为Scala中的json？

1 个答案: