如何用hadoop java API配置hdfs默认路径？

Question

我在Windows10上使用hadoop文件系统3.3.0和hadoop java客户端api。下面是hadoop配置文件。

==core-site.xml

<configuration>
    <property>
        <name>fs.default.name</name>
        <value>hdfs://localhost:9000</value>
     </property>
</configuration>

<configuration>
    <property>
        <name>dfs.replication</name>
          <value>1</value>
     </property>
     <property>
        <name>dfs.http.address</name>
          <value>localhost:50070</value>
     </property>        
    <property>
        <name>dfs.name.dir</name>
        <value>file:///C:/hadoop-3.3.0/data/hdfs/namenode</value>
     </property>
     <property>
          <name>dfs.data.dir</name>
          <value>file:///C:/hadoop-3.3.0/data/hdfs/datanode</value>
     </property>
</configuration>

Configuration conf = new Configuration();
conf.addResource(new Path("file:///C:/hadoop-3.3.0/etc/hadoop/core-site.xml"));
conf.addResource(new Path("file:///C:/hadoop-3.3.0/etc/hadoop/hdfs-site.xml"));
FileSystem hadoopFs = FileSystem.get(conf);

Path hadoopPath = new Path(filename);
        
FSDataOutputStream hadoopOutStream = null;
BufferedWriter bw = null;
        
if(hadoopFs.exists(hadoopPath)) {
    hadoopOutStream =hadoopFs.append(hadoopPath);
} else {
    hadoopOutStream = hadoopFs.create(hadoopPath, true); 
}
        
bw = new BufferedWriter(new OutputStreamWriter(hadoopOutStream,StandardCharsets.UTF_8));
bw.write("data....");
bw.close();
hadoopOutStream.close();

当我执行hadoop命令接口时,输出如下所示,

>hdfs dfs -ls /user/joseph
Found 1 items
-rw-r--r--   1 joseph supergroup     172120 2020-12-11 17:34 /user/joseph/saved_data.csv

保存文件的默认文件夹不包括在hadoop_home上，而是windows用户文件夹。如何修改默认保存文件夹？任何回复都是感谢的。最诚挚的问候

Answer 1

HADOOP_HOME是Hadoop安装所在的路径，它与hdfs路径无关。默认情况下，HDFS将在其/user/nameofuser目录中存储一个目录。/user部分可通过config dfs.user.home.dir.prefix配置，其默认值为/user您可以在hdfs客户端配置中更改它，使用其他前缀而不是/user