Jackson 的JAR包冲突问题

在maven编译过程中发现报出了如下的错误：

Exception in thread "main" java.lang.ExceptionInInitializerError
        at org.apache.spark.SparkContext.withScope(SparkContext.scala:701)
        at org.apache.spark.SparkContext.textFile(SparkContext.scala:830)
        at org.apache.spark.api.java.JavaSparkContext.textFile(JavaSparkContext.scala:172)
        at com.getui.test.spark.TextIO.main(TextIO.java:12)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.apache.hadoop.util.RunJar.run(RunJar.java:318)
        at org.apache.hadoop.util.RunJar.main(RunJar.java:232)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Incompatible Jackson version: 2.9.5
        at com.fasterxml.jackson.module.scala.JacksonModule$class.setupModule(JacksonModule.scala:64)
        at com.fasterxml.jackson.module.scala.DefaultScalaModule.setupModule(DefaultScalaModule.scala:19)
        at com.fasterxml.jackson.databind.ObjectMapper.registerModule(ObjectMapper.java:751)
        at org.apache.spark.rdd.RDDOperationScope$.<init>(RDDOperationScope.scala:82)
        at org.apache.spark.rdd.RDDOperationScope$.<clinit>(RDDOperationScope.scala)
        ... 10 more

后台查阅资料与查看报错发现，是由于Jackson这个工具库的版本不一致导致的。

解决方案：
排除其他对于Jackon的依赖，从而阻止Maven自动导入高版本的库：

<exclusions>
    <exclusion>
        <groupId>com.fasterxml.jackson.module</groupId>
        <artifactId>*</artifactId>
    </exclusion>
    <exclusion>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>*</artifactId>
    </exclusion>
</exclusions>

随后手动添加相同版本Jackon库的依赖项，重新import即可。

<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-scala_2.10</artifactId>
    <version>2.9.5</version>
</dependency>

<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-paranamer</artifactId>
    <version>2.9.5</version>
</dependency>
 
<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-jaxb-annotations</artifactId>
    <version>2.9.5</version>
</dependency>