java - How to add an object to an array of another object java

Question

I'm developing an Android app. My apps has a button and when I press this button I will parse an XML file, put the information of this file in some object and present this object in a expandable list. Also my XML file has this structure:

<?xml version="1.0" encoding="UTF-8"?>
<Programs>
    <Program programNumber="1" imgURL="http://www.photovideolife.com/userfiles/Placeholder%2001.jpg" description="Lorem ipsum dolor sit er elit">
        <Episode pN="1" episodeNumber="1" transmissionName="Titolo" date="29 Giu 2013" time1="14:30" time2="" channel="Real Time" channelLogo="https://lh6.googleusercontent.com/-XSh-9ngYJu4/ThiY-xl2EeI/AAAAAAAABmc/iz04VpL5hOs/s800/realtime.png">
        </Episode>
        <Episode pN="1" episodeNumber="1" transmissionName="Titolo" date="29 Giu 2013" time1="" time2="16:30" channel="DMAX" channelLogo="http://tv.zam.it/canali/dmax.png">
        </Episode>
        <Episode pN="1" episodeNumber="2" transmissionName="Titolo" date="01 Lug 2013" time1="14:30" time2="" channel="Real Time" channelLogo="https://lh6.googleusercontent.com/-XSh-9ngYJu4/ThiY-xl2EeI/AAAAAAAABmc/iz04VpL5hOs/s800/realtime.png">
        </Episode>
        <Episode pN="1" episodeNumber="2" transmissionName="Titolo" date="01 Lug 2013" time1="" time2="16:30" channel="DMAX" channelLogo="http://tv.zam.it/canali/dmax.png">
        </Episode>
    </Program>
</Programs>

I made 3 object: Episode, Program and Programs. I post here the implementation:

Episode.java

public class Episode {
    String pN, episodeNumber, transmissionName, date, time1, time2, channel, channelLogo;

    public String getpN() {
        return pN;
    }

    public void setpN(String pN) {
        this.pN = pN;
    }

    public String getEpisodeNumber() {
        return episodeNumber;
    }

    public void setEpisodeNumber(String episodeNumber) {
        this.episodeNumber = episodeNumber;
    }

    public String getTransmissionName() {
        return transmissionName;
    }

    public void setTransmissionName(String transmissionName) {
        this.transmissionName = transmissionName;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getTime1() {
        return time1;
    }

    public void setTime1(String time1) {
        this.time1 = time1;
    }

    public String getTime2() {
        return time2;
    }

    public void setTime2(String time2) {
        this.time2 = time2;
    }

    public String getChannel() {
        return channel;
    }

    public void setChannel(String channel) {
        this.channel = channel;
    }

    public String getChannelLogo() {
        return channelLogo;
    }

    public void setChannelLogo(String channelLogo) {
        this.channelLogo = channelLogo;
    }

}

Program.java

public class Program {
    public Episode[] episodes;

    String programNumber, imgUrl, description;

    public Episode[] getEpisodes() {
        return episodes;
    }

    public void setEpisodes(Episode[] episodes) {
        this.episodes = episodes;
    }

    public String getProgramNumber() {
        return programNumber;
    }

    public void setProgramNumber(String programNumber) {
        this.programNumber = programNumber;
    }

    public String getImgUrl() {
        return imgUrl;
    }

    public void setImgUrl(String imgUrl) {
        this.imgUrl = imgUrl;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

}

Programs.java

public class Programs {
    public Program[] programs;

    public Program[] getPrograms() {
        return programs;
    }

    public void setPrograms(Program[] programs) {
        this.programs = programs;
    }
}

To parse the XML file I made this class:

XmlParser.java

import it.lucgian84.models.Episode;
import it.lucgian84.models.Program;
import it.lucgian84.models.Programs;

import java.io.ByteArrayInputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

import android.renderscript.Element;
import android.util.Log;

public class XmlParser {
    private String xml;
    private Programs programs;
    private Program program = new Program();
    private Episode episode = new Episode();

    public XmlParser(String xml) {
        this.xml = xml;
    }

    public void parseXml() {
        try {
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
                    .newInstance();
            DocumentBuilder documentBuilder = documentBuilderFactory
                    .newDocumentBuilder();
            Document document = documentBuilder.parse(new InputSource(
                    new ByteArrayInputStream(xml.getBytes("utf-8"))));
            document.getDocumentElement().normalize();
            NodeList nodeList = document.getElementsByTagName("Program");
            for (int i = 0; i < nodeList.getLength(); i++) {
                Node nodeItem = nodeList.item(i);
                if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                    Element element = (Element) nodeItem;
                    program.setProgramNumber(((org.w3c.dom.Element) element)
                            .getAttribute("programNumber"));
                    program.setImgUrl(((org.w3c.dom.Element) element)
                            .getAttribute("imgUrl"));
                    program.setDescription(((org.w3c.dom.Element) element)
                            .getAttribute("description"));
                }
            }
            nodeList = document.getElementsByTagName("Episode");
             for (int i = 0; i < nodeList.getLength(); i++) {
                 Node nodeItem = nodeList.item(i);
                 if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                     Element element = (Element) nodeItem;
                     episode.setpN(((org.w3c.dom.Element) element)
                                .getAttribute("pN"));
                     episode.setEpisodeNumber(((org.w3c.dom.Element) element)
                            .getAttribute("episodeNumber"));
                     episode.setTransmissionName(((org.w3c.dom.Element) element)
                            .getAttribute("transmissionName"));
                     episode.setDate(((org.w3c.dom.Element) element)
                            .getAttribute("date"));
                     episode.setTime1(((org.w3c.dom.Element) element)
                            .getAttribute("time1"));
                     episode.setTime2(((org.w3c.dom.Element) element)
                            .getAttribute("time2"));
                     episode.setChannel(((org.w3c.dom.Element) element)
                            .getAttribute("channel"));
                     episode.setChannelLogo(((org.w3c.dom.Element) element)
                            .getAttribute("channelLogo"));
                 }
             }
        } catch (Exception e) {
            Log.d("XML", "Exception: " + e);
        }
    }

}

I'm not sure how to insert the object Episode to the array Program and the object Program to the array Programs. I hope you can help me to find a solution of this issue. Thank you

score 1 · Accepted Answer

List<Programs> programsList = new ArrayList<Programs>(); //create list of Programs
List<Program> programList = new ArrayList<Program>(); // create list of Program
programsList.add(new Program()); //object Program to the array Programs
programList.add(new Episode()); //insert the object Episode to the array Program

Expanding:

with your current implementation:

public void parseXml() {
    try {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
                .newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory
                .newDocumentBuilder();
        Document document = documentBuilder.parse(new InputSource(
                new ByteArrayInputStream(xml.getBytes("utf-8"))));
        document.getDocumentElement().normalize();
        NodeList nodeList = document.getElementsByTagName("Program");
        for (int i = 0; i < nodeList.getLength(); i++) {
            Node nodeItem = nodeList.item(i);
            if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                Element element = (Element) nodeItem;

                Program program = new Program();

                program.setProgramNumber(((org.w3c.dom.Element) element)
                        .getAttribute("programNumber"));
                program.setImgUrl(((org.w3c.dom.Element) element)
                        .getAttribute("imgUrl"));
                program.setDescription(((org.w3c.dom.Element) element)
                        .getAttribute("description"));

                programsList.add(program);
            }
        }
        nodeList = document.getElementsByTagName("Episode");
         for (int i = 0; i < nodeList.getLength(); i++) {   
             Node nodeItem = nodeList.item(i);
             if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                 Element element = (Element) nodeItem;

                 Episode episode = new Episode(); //creating new episode object

                 episode.setpN(((org.w3c.dom.Element) element)
                            .getAttribute("pN"));
                 episode.setEpisodeNumber(((org.w3c.dom.Element) element)
                        .getAttribute("episodeNumber"));
                 episode.setTransmissionName(((org.w3c.dom.Element) element)
                        .getAttribute("transmissionName"));
                 episode.setDate(((org.w3c.dom.Element) element)
                        .getAttribute("date"));
                 episode.setTime1(((org.w3c.dom.Element) element)
                        .getAttribute("time1"));
                 episode.setTime2(((org.w3c.dom.Element) element)
                        .getAttribute("time2"));
                 episode.setChannel(((org.w3c.dom.Element) element)
                        .getAttribute("channel"));
                 episode.setChannelLogo(((org.w3c.dom.Element) element)
                        .getAttribute("channelLogo"));

                 programList.add(episode);
             }
         }
    } catch (Exception e) {
        Log.d("XML", "Exception: " + e);
    }
}

Another alternative:

public void parseXml() {
    try {
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
                .newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory
                .newDocumentBuilder();
        Document document = documentBuilder.parse(new InputSource(
                new ByteArrayInputStream(xml.getBytes("utf-8"))));
        document.getDocumentElement().normalize();
        NodeList nodeList = document.getElementsByTagName("Program");
        for (int i = 0; i < nodeList.getLength(); i++) {
            Node nodeItem = nodeList.item(i);
            if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                Element element = (Element) nodeItem;

                String programNumber = ((org.w3c.dom.Element) element)
                        .getAttribute("programNumber");
                String imgUrl = ((org.w3c.dom.Element) element)
                            .getAttribute("imgUrl");
                String description = ((org.w3c.dom.Element) element)
                                .getAttribute("description");

                programsList.add(new Program(programNumber, imgUrl, description));
            }
        }
        nodeList = document.getElementsByTagName("Episode");
         for (int i = 0; i < nodeList.getLength(); i++) {   
             Node nodeItem = nodeList.item(i);
             if (nodeItem.getNodeType() == Node.ELEMENT_NODE) {
                 Element element = (Element) nodeItem;

                 String pN = ((org.w3c.dom.Element) element)
                            .getAttribute("pN");
                 String episodeNumber = ((org.w3c.dom.Element) element)
                                .getAttribute("episodeNumber");
                 String transmissionName =  ((org.w3c.dom.Element) element)
                                    .getAttribute("transmissionName");
                 String date =  ((org.w3c.dom.Element) element)
                                        .getAttribute("date");
                 String time1 = ((org.w3c.dom.Element) element)
                                            .getAttribute("time1");
                 String time2 = ((org.w3c.dom.Element) element)
                                                .getAttribute("time2");
                 String channel = ((org.w3c.dom.Element) element)
                                                    .getAttribute("channel");
                 String channelLogo = ((org.w3c.dom.Element) element)
                                                        .getAttribute("channelLogo");

                 programList.add(new Episode(pN, episodeNumber, transmissionName, date, time1, time2, channel, channelLogo));
             }
         }
    } catch (Exception e) {
        Log.d("XML", "Exception: " + e);
    }
}

With alternatie approach, then you have to add specific constructors in your Program and Episode classes:

public class Program {
  public Program(String programNumber, String imgUrl, String description){
    setProgramNumber(programNumber);
    setImgUrl(imgUrl);
    setDescription(description);
  }

  ....the rest of your implementation...
}


public class Episode {
  public Episode(String pN, String episodeNumber, String transmissionName, String date, String time1, String time2, String channel, String channelLogo){
    setpN(pN);
    setEpisodeNumber(episodeNumber);
    setTransmissionName(transmissionName);
    setDate(date);
    setTime1(time1);
    setTime2(time2);
    setChannel(channel);
    setChannelLogo(channelLogo);
  }

  ....the rest of your implementation...
}

I would personally prefer alternative approach, since it is more of OO paradigm and easier to read (at least for me) and easier to cope with future changes
The code goes like this:
1. Objects Program and Episode are instantiated
2. Objects Program and Episode are populated
3. Objects Program and Episode are added to the list
Objects can be accessed from the list by using list.get(index) and can be altered while being in the list like: ((Program)list.get(index)).setDescription("my new description") and the list will be updated

java - How to add an object to an array of another object java

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