flink1.10配置rocksdb保存checkpoint時，idea運行報錯

首先，使用rocksdb需要引入依賴：

<!-- https://mvnrepository.com/artifact/org.apache.flink/flink-statebackend-rocksdb -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-statebackend-rocksdb_2.12</artifactId>
            <version>1.10.0</version>
        </dependency>

 但是在idea中運行時，仍然報錯，如下：

Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Could not find a file system implementation for scheme 'hdfs'. The scheme is not directly supported by Flink and no Hadoop file system to support this scheme could be loaded.
	at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:450)
	at org.apache.flink.core.fs.FileSystem.get(FileSystem.java:362)
	at org.apache.flink.core.fs.Path.getFileSystem(Path.java:298)
	at org.apache.flink.runtime.state.filesystem.FsCheckpointStorage.<init>(FsCheckpointStorage.java:64)
	at org.apache.flink.runtime.state.filesystem.FsStateBackend.createCheckpointStorage(FsStateBackend.java:490)
	at org.apache.flink.contrib.streaming.state.RocksDBStateBackend.createCheckpointStorage(RocksDBStateBackend.java:477)
	at org.apache.flink.runtime.checkpoint.CheckpointCoordinator.<init>(CheckpointCoordinator.java:279)
	... 24 more
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Cannot support file system for 'hdfs' via Hadoop, because Hadoop is not in the classpath, or some classes are missing from the classpath.
	at org.apache.flink.runtime.fs.hdfs.HadoopFsFactory.create(HadoopFsFactory.java:184)
	at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:446)
	... 30 more
Caused by: java.lang.NoClassDefFoundError: org/apache/hadoop/hdfs/HdfsConfiguration
	at org.apache.flink.runtime.fs.hdfs.HadoopFsFactory.create(HadoopFsFactory.java:85)
	... 31 more
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.hdfs.HdfsConfiguration
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 32 more

這是因爲本地idea運行時，沒有找到Hadoop相關的包。因此還需要引入另外一個依賴：

<dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>2.7.6</version>
        </dependency>