如何从Java类读取？

Question

I'm at really beginning with Android dev and Objective programming so this question will be so stupid for you.. I know, but I wanna ask, how can I read from a java class?

This is my case: I came from C and C++ and I have to keep datas from an XML file. The datas are about places, so the items are: "Name", "Address", "Telephone number" and so on. Now, if I was in C maybe I will do an Array or a List, but, I wanna learn Java and the Objective programming so I made a class named "PointOfInterest" with all field, but I don't know if I'm writing well onto it and I don't know how to read from the class.. If I was in C or C++ with to for cicles I could go horizontally when the title is equal to the field "0" for example. But with Java classes??

How can I do? This is my code:

package com.example.findmyclients;

public class PointOfInterest {
    private String title;
    private String address;
    private String telephone;
    private String email;
    private String description;
    private String facebook;
    private String twitter;
    private String website;

    public void AnyPoint(String nome, String indirizzo, String telefono, String email, String description, String facebook, String twitter, String website){
        //super();
        this.title = nome;
        this.address = indirizzo;
        this.telephone = telefono;
        this.email = email;
        this.description = description;
        this.facebook = facebook;
        this.twitter = twitter;
        this.website = website;
    }

    public String prova(String nome){
        if(title.contains(nome)){
            return this.address;
        }
        return nome;
    }
}

and this is my "try" to keep into the class datas from xml:

for (int i = 0; i < markers.getLength(); i++) {

    //PointOfInterest p = point.get(i+1);

    Element item = (Element) markers.item(i);
    String name = item.getAttribute("name");
    String address = item.getAttribute("address");
    String stringLat = item.getAttribute("lat");
    String stringLong = item.getAttribute("long");
    String icon = item.getAttribute("icon"); //assigned variable for the XML icon attribute

    String desc = item.getAttribute("descrizione");
    String tel = item.getAttribute("tel");
    String email = item.getAttribute("email");
    String facebook = item.getAttribute("facebook");
    String twitter = item.getAttribute("twitter");
    String web = item.getAttribute("web");

    Double lat = Double.valueOf(stringLat);
    Double lon = Double.valueOf(stringLong);

    PointOfInterest p = new PointOfInterest();
    p.AnyPoint(name,address,tel,email,desc,facebook,twitter,web);

[...]

Answer 1

I'm afraid to misunderstand what you want to get, precisely I don't get to the meaning of 'how to read from the class'

Nevertheless if I understand it correctly, you may want to use Java Collections Framework .like as HashMap or TreeMap.

If you want to get PointOfInterest instance with some 'key', you can do it as followings.

Map<String, PointOfInterest> nameMap = new HashMap<<String, PointOfInterest>();
nameMap.put(p.getName, p);


PointOfInterest anotherP = nameMap.get("foo");

if (anotherP != null)  {  // there is a instance with a name of "foo"
   ...
} 

By the way, I strongly want to suggest to use Immutable object. For example

public class PointOfInterest {
    private final String title;
    private final String address;
    private final String telephone;
    ....

    //constructure
    public PointOfInterest(String title, String address, ... ) {
        this.title = title;
        ....
    }
  ....
 }

If this is not what you want to know, please let me understand it. I hope there is a way that I can help you.