Jackson版本太旧

Question

我有以下build.sbt文件：

name := "myProject"

version := "1.0"

scalaVersion := "2.11.8"

javaOptions ++= Seq("-Xms512M", "-Xmx2048M", "-XX:MaxPermSize=2048M", "-XX:+CMSClassUnloadingEnabled")


dependencyOverrides ++= Set(
  "com.fasterxml.jackson.core" % "jackson-core" % "2.8.1"
)

// additional libraries
libraryDependencies ++= Seq(
  "org.apache.spark" %% "spark-core" % "2.0.0" % "provided",
  "org.apache.spark" %% "spark-sql" % "2.0.0" % "provided",
  "org.apache.spark" %% "spark-hive" % "2.0.0" % "provided",
  "com.databricks" %% "spark-csv" % "1.4.0",
  "org.scalactic" %% "scalactic" % "2.2.1",
  "org.scalatest" %% "scalatest" % "2.2.1" % "test",
  "org.scalacheck" %% "scalacheck" % "1.12.4",
  "com.holdenkarau" %% "spark-testing-base" % "2.0.0_0.4.4" % "test",
)

然而，当我运行代码时，我得到了这个错误：

An exception or error caused a run to abort. 
java.lang.ExceptionInInitializerError
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Jackson version is too old 2.4.4
    at com.fasterxml.jackson.module.scala.JacksonModule$class.setupModule(JacksonModule.scala:56)
    at com.fasterxml.jackson.module.scala.DefaultScalaModule.setupModule(DefaultScalaModule.scala:19)
    at com.fasterxml.jackson.databind.ObjectMapper.registerModule(ObjectMapper.java:549)
    at org.apache.spark.rdd.RDDOperationScope$.<init>(RDDOperationScope.scala:82)
    at org.apache.spark.rdd.RDDOperationScope$.<clinit>(RDDOperationScope.scala)
    ... 58 more

为什么会这样呢？我已经在dependencyOverrides中添加了一个较新版本的杰克逊(在查看了这里的Spark Parallelize? (Could not find creator property with name 'id')之后)，所以不应该使用旧版本。

Answer 1

jackson-core和jackson-databind版本应该匹配(我认为至少是次要版本)。

因此，删除dependencyOverrides并让

libraryDependencies ++= Seq(
  ...
  "com.fasterxml.jackson.core" % "jackson-databind" % "2.8.1"
)

或者在dependencyOverrides中同时指定两者

dependencyOverrides ++= Set(
  "com.fasterxml.jackson.core" % "jackson-core" % "2.8.1"
  "com.fasterxml.jackson.core" % "jackson-databind" % "2.8.1"
)

虽然我不确定我明白你在做什么；但链接的问题似乎是说你应该使用旧版本(2.4.4)。