Is there a way to read a file from GitHub and print it in the console using Java?

Question

I want to store a file in Github as a string in java and process it later in the code. How can I do that ?

Answer 1

We can execute curl commands in Java and use Basic authentication to access files.

URL url;String username="username",password="password",file="";
        try {
            url = new URL("https://www.bitbucket.com/raw-file-url");
            URLConnection uc;
            uc = url.openConnection();

            uc.setRequestProperty("X-Requested-With", "Curl");
            ArrayList<String> list=new ArrayList<String>();
            String userpass = username + ":" + password;
            String basicAuth = "Basic " + new String(new Base64().encode(userpass.getBytes()));//needs Base64 encoder, apache.commons.codec
            uc.setRequestProperty("Authorization", basicAuth);

            BufferedReader reader = new BufferedReader(new InputStreamReader(uc.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) 
                file=file+line+"\n";
            System.out.println(file);
            return file;

        } catch (IOException e) {
            System.out.println("Wrong username and password");
            return null;

        }

Answer 2

This is plain java way of doing this... I used standard java.net.URL api and Base64 class to connect github and print a json like the below example :

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Base64;

public class GitConnect {
    public static void main(String... args) throws Exception {

        java.net.URL url = null;
        String username = "user";
        String password = "gitpwd";
        String file = "";
        try {
            url = new java.net.URL("https://raw.githubusercontent.com/lrjoshi/webpage/master/public/post/c159s.csv");
            java.net.URLConnection uc;
            uc = url.openConnection();

            uc.setRequestProperty("X-Requested-With", "Curl");
            java.util.ArrayList<String> list = new java.util.ArrayList<String>();
            String userpass = username + ":" + password;
            String basicAuth = "Basic " + new String(Base64.getEncoder().encode(userpass.getBytes()));//needs Base64 encoder, apache.commons.codec
            uc.setRequestProperty("Authorization", basicAuth);

            BufferedReader reader = new BufferedReader(new InputStreamReader(uc.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null)
                file = file + line + "\n";
            System.out.println(file);

        } catch (IOException e) {
            System.out.println("Wrong username and password");
        }
    }
}

Answer 3

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;
import java.util.Map;


public static String getTextFromGithub(String link) {
    URL Url = null;
    try {
        Url = new URL(link);
    } catch (MalformedURLException e1) {
        e1.printStackTrace();
    }
    HttpURLConnection Http = null;
    try {
        Http = (HttpURLConnection) Url.openConnection();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    Map<String, List<String>> Header = Http.getHeaderFields();
    
    for (String header : Header.get(null)) {
        if (header.contains(" 302 ") || header.contains(" 301 ")) {
            link = Header.get("Location").get(0);
            try {
                Url = new URL(link);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }
            try {
                Http = (HttpURLConnection) Url.openConnection();
            } catch (IOException e) {
                e.printStackTrace();
            }
            Header = Http.getHeaderFields();
        }
    }
    InputStream Stream = null;
    try {
        Stream = Http.getInputStream();
    } catch (IOException e) {
        e.printStackTrace();
    }
    String Response = null;
    try {
        Response = GetStringFromStream(Stream);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return Response;
}

private static String GetStringFromStream(InputStream Stream) throws IOException {
    if (Stream != null) {
        Writer Writer = new StringWriter();

        char[] Buffer = new char[2048];
        try {
            Reader Reader = new BufferedReader(new InputStreamReader(Stream, "UTF-8"));
            int counter;
            while ((counter = Reader.read(Buffer)) != -1) {
                Writer.write(Buffer, 0, counter);
            }
        } finally {
            Stream.close();
        }
        return Writer.toString();
    } else {
        return "No Contents";
    }
}