JAVA高级面试进阶训练营视频教程

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在给代码带包成jar后，放到环境中运行出现如下错误：

Exception in thread "main" java.io.IOException: No FileSystem for scheme: file
	at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2644)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2651)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:92)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2687)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2669)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:371)
	at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
	at org.apache.spark.sql.catalyst.catalog.SessionCatalog.makeQualifiedPath(SessionCatalog.scala:115)
	at org.apache.spark.sql.catalyst.catalog.SessionCatalog.createDatabase(SessionCatalog.scala:145)
	at org.apache.spark.sql.catalyst.catalog.SessionCatalog.<init>(SessionCatalog.scala:89)
	at org.apache.spark.sql.internal.SessionState.catalog$lzycompute(SessionState.scala:95)
	at org.apache.spark.sql.internal.SessionState.catalog(SessionState.scala:95)
	at org.apache.spark.sql.internal.SessionState$$anon$1.<init>(SessionState.scala:112)
	at org.apache.spark.sql.internal.SessionState.analyzer$lzycompute(SessionState.scala:112)
	at org.apache.spark.sql.internal.SessionState.analyzer(SessionState.scala:111)
	at org.apache.spark.sql.execution.QueryExecution.assertAnalyzed(QueryExecution.scala:49)
	at org.apache.spark.sql.Dataset$.ofRows(Dataset.scala:64)
	at org.apache.spark.sql.SparkSession.baseRelationToDataFrame(SparkSession.scala:382)
	at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:143)
	at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:122)
	at org.elasticsearch.spark.sql.EsSparkSQL$.esDF(EsSparkSQL.scala:52)
	at org.elasticsearch.spark.sql.EsSparkSQL$.esDF(EsSparkSQL.scala:66)
	at org.elasticsearch.spark.sql.package$SparkSessionFunctions.esDF(package.scala:58)
	at SQLAttack$.getDayDataByES(SQLAttack.scala:51)
	at SQLAttack$.main(SQLAttack.scala:25)
	at SQLAttack.main(SQLAttack.scala)

这是因为 HDFS 的配置文件没写好，更改方式如下：

找到自己项目保存库的位置，依次点击：

File -> Settings -> Build,Execution,Deployment -> Build Tools -> Maven -> Local repository

这里的 Local repository 就是项目保存库的位置。在这里面依次打开文件位置：

\repository\org\apache\hadoop\hadoop-common\2.7.2\

用 rar 打开 hadoop-common-2.7.2.jar ，把里面的 core-default.xml 下载到本地，打开添加更改，在 <!--- global properties --> 添加如下字段：

<!--- global properties -->
<property>
        <name>fs.hdfs.impl</name>
        <value>org.apache.hadoop.hdfs.DistributedFileSystem</value>
        <description>The FileSystem for hdfs: uris.</description>
</property>
<property>
        <name>fs.file.impl</name>
        <value>org.apache.hadoop.fs.LocalFileSystem</value>
        <description>The FileSystem for hdfs: uris.</description>
</property>

将更改后的 core-default.xml 重新放入 hadoop-common-2.7.2.jar 中，再次打包就可以运行了