A file-like MogileFS client for Java
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Latest commit 3a32669 Oct 11, 2016 @hrchu hrchu committed on GitHub Ignore eclipse and Intellij metadata



A file-like MogileFS client for Java.

Start using

You can obtain Moji from Maven Central using the following identifier:


  • java.io.File like API
  • Supports writing streams of unknown length
  • Unit/Integration tests
  • Spring friendly
  • Tracker connection pooling with balancing between hosts and strategies for dealing with failed nodes
  • Local file system implementation for faking in tests (fm.last.moji.local.LocalFileSystemMoji)


Using plain-old-Java

    SpringMojiBean moji = new SpringMojiBean();

Using the Spring framework

Set some properties for your context:


Import the Moji Spring context:

    <import resource="moji-context.xml" />

Or create a Moji spring bean:

    <bean id="moji" class="fm.last.moji.spring.SpringMojiBean">
      <property name="addressesCsv" value="${moji.tracker.address}" />
      <property name="domain" value="${moji.domain}" />
      <property name="maxActive" value="${moji.pool.max.active:100}" />
      <property name="maxIdle" value="${moji.pool.max.idle:10}" />
      <property name="testOnBorrow" value="${moji.pool.test.on.borrow:true}" />


Create/update a remote file

    MojiFile rickRoll = moji.getFile("rick-astley");
    moji.copyToMogile(new File("never-gonna-give-you-up.mp3"), rickRoll);

Or in a given storage class:

    MojiFile rickRoll = moji.getFile("rick-astley", "music-meme");

Get the remote file size

    long length = rickRoll.length();

Rename the remote file


Check the existence of a remote file

    MojiFile abba = moji.getFile("voulez-vous");
    if (abba.exists()) {

Delete the remote file


Download a remote file

    MojiFile fooFighters = moji.getFile("stacked-actors");
    fooFighters.copyToFile(new File("foo-fighters.mp3"));

Modify the storage class of a remote file


Stream from a remote file

    InputStream stream = null;
    try {
      stream = fooFighters.getInputStream();
      // Do something streamy
      //   stream.read();
    } finally {

Stream to a remote file

This will either create a new file or overwrite an existing file's contents

    OutputStream stream = null;
    try {
      stream = fooFighters.getOutputStream();
      // Do something streamy
      //   stream.write(...);
    } finally {

List remote files by prefix

    List<MojiFile> files = moji.list("abba-");
    for(MojiFile file : files) {
      // abba-waterloo, abba-voulez-vous, abba-fernado, etc.

Impose a limit on the number of items returned:

    List<MojiFile> files = moji.list("abba-", 10);
    for(MojiFile file : files) {
      // abba-waterloo, abba-voulez-vous, abba-fernado, etc. - maximum of 10

Get the locations of a remote file

    File fooFighters = moji.getFile("in-your-honour"); 
    List<URL> paths = fooFighters.getPaths();
    //,, etc

Get the attributes of a remote file

Note: this is only supported on more recent versions of MogileFS.

    File fooFighters = moji.getFile("in-your-honour"); 
    MojiFileAttributes attributes = fooFighters.getAttibutes();

    String storageClass = attributes.getStorageClass();
    int deviceCount = attributes.getDeviceCount();
    int fid = attributes.getFid();

Running the integration tests

To run the integration tests, you can make use of ready-to-use docker image, or setup the environment manually. For manual setup, you need:

  • A unix-type system (for shell script execution - FIXME)
  • A test MogileFS tracker and a storage node (installation instructions)
  • mogdelete, moglistkeys, mogupload
  • uuencode (apt-get install sharutils)

MogileFS integration test properties config:

  • These properties should be set in /moji.properties on the classpath.
  • Set your Tracker address with the property:

  • Declare your Mogile domain with the property:

  • Declare two storage classes (class assigned here should have devcount=1 if there are multiple storage nodes in the environment) in your Mogile instance and assign them with these properties:

  • Choose a key prefix to avoid any key clashes with real data (you're using a test instance right?) or other tests. Otherwise we might get unexpected behaviour and file deletions:



This project uses the Maven build system.


All contributions are welcome. Please use the Last.fm codeformatting profile found in the lastfm-oss-config project for formatting your changes.


Copyright 2012-2016 Last.fm & The "mogilefs-moji" committers.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.