UsageMFSFilesAPI.java

package io.ipfs.api.demo;

import io.ipfs.api.IPFS;
import io.ipfs.api.NamedStreamable;
import io.ipfs.api.WriteFilesArgs;
import io.ipfs.multiaddr.MultiAddress;
import java.io.IOException;
import java.util.List;
import java.util.Map;

/*
From MFS api documentation: https://github.com/ipfs/js-ipfs/blob/master/docs/core-api/FILES.md#the-mutable-files-api
The Mutable File System (MFS) is a virtual file system on top of IPFS that exposes a Unix like API over a virtual directory.
It enables users to write and read from paths without having to worry about updating the graph.

Useful links:
rpc api - https://docs.ipfs.tech/reference/kubo/rpc/#getting-started
proto.school - https://proto.school/mutable-file-system/01
ipfs.tech - https://docs.ipfs.tech/concepts/file-systems/#mutable-file-system-mfs

 */
public class UsageMFSFilesAPI {

  public UsageMFSFilesAPI(IPFS ipfsClient) {
    try {
      run(ipfsClient);
    } catch (IOException ioe) {
      ioe.printStackTrace();
    }
  }

  private void run(IPFS ipfs) throws IOException {

    // remove 'my' directory to clean up from a previous run
    ipfs.files.rm("/my", true, true);

    // To create a new directory nested under others that don't yet exist, you need to explicitly
    // set the value of parents to true
    ipfs.files.mkdir("/my/directory/example", true);

    // Check directory status
    String directoryPath = "/my/directory/example";
    Map exampleDirectory = ipfs.files.stat(directoryPath);
    // {Hash=QmV1a2QoUnB9fPzjZd1GunGR53isuhcWWNCS5Bg3mJyv8N, Size=0, CumulativeSize=57, Blocks=1,
    // Type=directory}

    // Add a file
    String contents = "hello world!";
    String filename = "hello.txt";
    String filePath = directoryPath + "/" + filename;
    NamedStreamable ns = new NamedStreamable.ByteArrayWrapper(filename, contents.getBytes());
    ipfs.files.write(filePath, ns, true, true);

    // Read contents of a file
    String fileContents = new String(ipfs.files.read(filePath));
    System.out.println(fileContents);

    // Write a file using builder pattern
    String ipfsFilename = "ipfs.txt";
    String fullIpfsPath = directoryPath + "/" + ipfsFilename;
    NamedStreamable ipfsFile =
        new NamedStreamable.ByteArrayWrapper(ipfsFilename, "ipfs says hello".getBytes());
    WriteFilesArgs args = WriteFilesArgs.Builder.newInstance().setCreate().setParents().build();
    ipfs.files.write(fullIpfsPath, ipfsFile, args);

    // List directory contents
    List<Map> ls = ipfs.files.ls(directoryPath);
    for (Map entry : ls) {
      System.out.println(entry.get("Name"));
    }

    // Copy file to another directory
    String copyDirectoryPath = "/my/copy/";
    ipfs.files.cp(filePath, copyDirectoryPath + filename, true);
    ls = ipfs.files.ls(copyDirectoryPath);
    for (Map entry : ls) {
      System.out.println(entry.get("Name"));
    }

    // Move file to another directory
    String duplicateDirectoryPath = "/my/duplicate/";
    ipfs.files.mkdir(duplicateDirectoryPath, false);
    ipfs.files.mv(copyDirectoryPath + filename, duplicateDirectoryPath + filename);
    ls = ipfs.files.ls(duplicateDirectoryPath);
    for (Map entry : ls) {
      System.out.println(entry.get("Name"));
    }

    // Remove a directory
    ipfs.files.rm(copyDirectoryPath, true, true);
    ls = ipfs.files.ls("/my");
    for (Map entry : ls) {
      System.out.println(entry.get("Name"));
    }
  }

  public static void main(String[] args) {
    IPFS ipfsClient = new IPFS(new MultiAddress("/ip4/127.0.0.1/tcp/5001"));
    new UsageMFSFilesAPI(ipfsClient);
  }
}