curl -u username:password https://example.com/xyz/abc

String username="myusername";
    String password="mypassword";
    String url="https://www.example.com/xyz/abc";
       String[] command = {"curl", "-u" ,"Accept:application/json", username, ":" , password , url};
        ProcessBuilder process = new ProcessBuilder(command);
        Process p;
        try
        {
            p = process.start();
             BufferedReader reader =  new BufferedReader(new InputStreamReader(p.getInputStream()));
                StringBuilder builder = new StringBuilder();
                String line = null;
                while ( (line = reader.readLine()) != null) {
                        builder.append(line);
                        builder.append(System.getProperty("line.separator"));
                }
                String result = builder.toString();
                System.out.print(result);

        }
        catch (IOException e)
        {   System.out.print("error");
            e.printStackTrace();
        }

String[] command = {"curl", "-u" ,"Accept:application/json", username, ":" , password , url};

String[] command = {"curl", "-H", "Accept:application/json", "-u", username+":"+password , url};