OJAI/MapR-DB Sample code to save/get binary content

demo.MapRDBSJSONType.java

package demo;

import com.mapr.db.MapRDB;
import com.mapr.db.Table;
import org.ojai.Document;

import javax.print.Doc;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.UUID;

public class MapRDBSJSONType {

  static final String TABLE_NAME = "/apps/demo";
  static Table table = null;

  public static void main(String[] args) throws Exception {

    String employeePic = "/Users/tgrall/Downloads/jdoe.png";
    String imageRestoreTo = "/Users/tgrall/Downloads/tmp/";

    MapRDBSJSONType app = new MapRDBSJSONType();
    app.insertEmployee("jdoe", "John", "Doe", employeePic);
    app.readEmployee("jdoe", imageRestoreTo );

    if (table != null) {
      table.close();
    }
  }

  public MapRDBSJSONType() {

      if (MapRDB.tableExists(TABLE_NAME)) {
        table = MapRDB.getTable(TABLE_NAME);
      } else {
        table = MapRDB.createTable(TABLE_NAME);
      }


  }


  private void insertEmployee(String id, String firstName, String lastName, String picture) throws IOException {

    System.out.println("\n== ==  WRITE TO MAPR-DB  == == == ");

    Document emp = MapRDB.newDocument()
            .set("_id",id)
            .set("first_name",firstName)
            .set("last_name", lastName);

    System.out.println(emp);

    // import an image
    byte[] imageAsBytes = extractBytes(picture);
    emp.set("image", imageAsBytes);

    // save the document in the MapR DB Table
    table.insertOrReplace(emp);
    System.out.println("\n== == == == == ");

  }

  private void readEmployee(String id, String location) throws Exception {

    Document emp = table.findById(id);

    System.out.println("\n== ==  READ FROM MAPR-DB  == == == ");
    System.out.println(emp);



    byte[] imageAsBytes = emp.getBinary("image").array();
    String fileCreated = saveImageToFile(imageAsBytes, location);

    System.out.println("\n\t File saved at : "+ location + fileCreated);
    System.out.println("\n== == == == == ");


  }

  /**
   * Get the bytes of the file passes as parameter
   * @param fileName
   * @return
   * @throws java.io.IOException
   */
  public byte[] extractBytes (String fileName) throws IOException {
    FileInputStream fileInputStream=null;
    File file = new File(fileName);
    byte[] bFile = new byte[(int) file.length()];
    try {
      //convert file into array of bytes
      fileInputStream = new FileInputStream(file);
      fileInputStream.read(bFile);
      fileInputStream.close();
    }catch(Exception e){
      e.printStackTrace();
    }
    return bFile;
  }

  /**
   * Save bytes into a file
   * @param imagesAsBytes
   * @param location
   * @return
   * @throws Exception
   */
  public String saveImageToFile( byte[] imagesAsBytes , String location  ) throws Exception {
    String fileName = location+ "maprdb-json-"+    UUID.randomUUID().toString() +".png";
    try (FileOutputStream fos = new FileOutputStream(fileName)) {
      fos.write(imagesAsBytes);
    } catch (IOException ioe) {
      ioe.printStackTrace();
    }
    return fileName;

  }

}