"Wrong FS... expected: file:///" when trying to read file from HDFS in Java

Question

I am unable to read a file from HDFS using Java:

String hdfsUrl = "hdfs://<ip>:<port>";
Configuration configuration = new Configuration();
configuration.set("fs.defaultFS", hdfsUrl);
FileSystem fs = FileSystem.get(configuration);
Path filePath = new Path(hdfsUrl + "/projects/harmonizome/data/achilles/attribute_list_entries.txt.gz");
FSDataInputStream fsDataInputStream = fs.open(filePath);

SEVERE: Servlet.service() for servlet [edu.mssm.pharm.maayanlab.Harmonizome.api.DownloadAPI] in context with path [/Harmonizome] threw exception
java.lang.IllegalArgumentException: Wrong FS: hdfs://146.203.54.165:8020/projects/harmonizome/data/achilles/attribute_list_entries.txt.gz, expected: file:///
    at org.apache.hadoop.fs.FileSystem.checkPath(FileSystem.java:310)
    at org.apache.hadoop.fs.RawLocalFileSystem.pathToFile(RawLocalFileSystem.java:47)
    at org.apache.hadoop.fs.RawLocalFileSystem.getFileStatus(RawLocalFileSystem.java:357)
    at org.apache.hadoop.fs.FilterFileSystem.getFileStatus(FilterFileSystem.java:245)
    at org.apache.hadoop.fs.ChecksumFileSystem$ChecksumFSInputChecker.<init>(ChecksumFileSystem.java:125)
    at org.apache.hadoop.fs.ChecksumFileSystem.open(ChecksumFileSystem.java:283)
    at org.apache.hadoop.fs.FileSystem.open(FileSystem.java:356)
    at edu.mssm.pharm.maayanlab.Harmonizome.api.DownloadAPI.readLines(DownloadAPI.java:37)
    at edu.mssm.pharm.maayanlab.Harmonizome.api.DownloadAPI.doGet(DownloadAPI.java:27)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
...

I didn't setup our HDFS, so I don't know what I don't know. Any help is appreciated.

Solution

Try this:

Configuration configuration = new Configuration();
FileSystem fs = FileSystem.get(new URI(<url:port>), configuration);
Path filePath = new Path(<path/to/file>);
FSDataInputStream fsDataInputStream = fs.open(filePath);
BufferedReader br = new BufferedReader(new InputStreamReader(fsDataInputStream));

Please refer to http://techidiocy.com/java-lang-illegalargumentexception-wrong-fs-expected-file/

A similar problem is addressed.

Comments

[scoa]

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.

[jds]

I agree with @scoa. I was able to resolve my problem using this link and have edited your answer with the working code.

[java_bee]

@scoa thanks for suggestion. I will follow this in future.

[Worse_Username]

I don't get it. What was the root cause?

[akki]

Now the link is invalid & I can't know the root cause anymore 😅

[theannouncer]

Archived version: web.archive.org/web/20150805043209/http://techidiocy.com/…

[theannouncer]

From link, for posterity: "Your Configuration object is not initialized properly because of that it is trying to find this file in your local file system where it doesn’t exists because file [you are accessing] exists on HDFS."