java.lang.UnsupportedOperationException：未由DistributedFileSystem实现实现

如果需要将hdfs声明为分布式的，我将使用单节点hadoop集群（2.6.2）。我添加了hdfs、core、commonjar到项目构建路径，也需要jar到项目库。但是我现在得到了错误java.lang.UnsupportedOperationException：不是由我在应用程序上下文中配置的分布式文件系统实现实现的

Configuration conf = new Configuration();

conf.addResource(new Path("/usr/local/hadoop-2.6.2/etc/hadoop/core-site.xml"));
        conf.addResource(new Path("/usr/local/hadoop-2.6.2/etc/hadoop/hdfs-site.xml"));
        conf.addResource(new Path("/usr/local/hadoop-2.6.2/etc/hadoop/mapred-site.xml"));


conf.set("fs.defaultFS", "hdfs://localhost:8088");
FileSystem fileSystem = FileSystem.get(conf);

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您使用的依赖jar似乎有问题

我正在使用Hadoop 2.7.1

我试用了你的程序，在集群中得到了正确的结果。我得到了正确的输出

hdfs

作为方案

节目：

package com.myorg.hadooptests;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;

public class GetConfTest {
    public static void main(String[] args) throws Exception    {

        Configuration conf = new Configuration();

        conf.set("fs.defaultFS", "hdfs://MBALLUR:8020");
        FileSystem fs = FileSystem.get(conf);
        System.out.println(fs.getScheme());
    }
}

<dependencies>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-mapreduce-client-core</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>1.2.1</version>
    </dependency>

</dependencies>

Maven依赖项：

package com.myorg.hadooptests;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;

public class GetConfTest {
    public static void main(String[] args) throws Exception    {

        Configuration conf = new Configuration();

        conf.set("fs.defaultFS", "hdfs://MBALLUR:8020");
        FileSystem fs = FileSystem.get(conf);
        System.out.println(fs.getScheme());
    }
}

<dependencies>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-mapreduce-client-core</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>1.2.1</version>
    </dependency>

</dependencies>

org.apache.hadoop
hadoop通用
2.7.1
org.apache.hadoop
hadoop mapreduce客户端核心
2.7.1
org.apache.hadoop
hadoop内核
1.2.1

我的类路径设置为（我正在Windows上运行）：

package com.myorg.hadooptests;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;

public class GetConfTest {
    public static void main(String[] args) throws Exception    {

        Configuration conf = new Configuration();

        conf.set("fs.defaultFS", "hdfs://MBALLUR:8020");
        FileSystem fs = FileSystem.get(conf);
        System.out.println(fs.getScheme());
    }
}

<dependencies>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-mapreduce-client-core</artifactId>
        <version>2.7.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-core</artifactId>
        <version>1.2.1</version>
    </dependency>

</dependencies>

E:\HadoopTests\target>echo%CLASSPATH% .;e:\hdp\hadoop-2.7.1.2.3.0.0-2557\etc\hadoop\；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\ 共享\hadoop\common*；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\common\lib* ;e:\hdp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\hdfs*；e:\hdp\hadoop-2.7.1.2.3.0。 0-2557\share\hadoop\hdfs\lib*；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\map 减少*；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\mapreduce\lib*；e:\hdp\ha doop-2.7.1.2.3.0.0-2557\share\hadoop\tools*；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\sh 是\hadoop\tools\lib*；e:\hdp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\warn*；e:\h dp\hadoop-2.7.1.2.3.0.0-2557\share\hadoop\Thread\lib*

---

您在哪一行获得此异常？最后一行FileSystem=FileSystem.get（conf）；请帮帮我。这个问题发生了很多次…我会检查并回答答案。几个月前，我曾研究过一个类似的问题，并得到了解决。你能把你的maven依赖项发布给我吗？事实上，对于这个项目，我开始使用maven。但后来它给出了一个问题，所以我改为纯JavaEE透视。