再說異常之前 先將專案的pom檔案配置發一下

<dependencies>
    <dependency>
        <groupId>org.apache.mahout</groupId>
        <artifactId>mahout-core</artifactId>
        <version>0.9</version>
    </dependency>
    <dependency>
        <groupId>org.apache.mahout</groupId>
        <artifactId>mahout-integration</artifactId>
        <version>0.9</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-client</artifactId>
        <version>2.9.0</version>
    </dependency>

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.2</version>
    </dependency>

</dependencies>
 

異常1

org.apache.hadoop.ipc.RemoteException: Server IPC version 9 cannot communicate with client version 4

經檢查，是因為在mahout-core依賴中，依賴了低版本的hdfs-core包，導致hadoop-client中依賴的2.9.0的版本被覆蓋。。。

所以我們只需要將mahout-core依賴的低版本hdfs-core移除即可。。

pom見下：

<dependency>
    <groupId>org.apache.mahout</groupId>
    <artifactId>mahout-core</artifactId>
    <version>0.9</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
        </exclusion>
    </exclusions>
</dependency>
 

異常2

org.apache.hadoop.fs.UnsupportedFileSystemException: No FileSystem for scheme “hdfs”

解決辦法：

Configuration configuration= new Configuration();

configuration.set("fs.hdfs.impl",org.apache.hadoop.hdfs.DistributedFileSystem.class.getName());