CODEWITHSUNDEEP
javadictionary
Iñaki
Iñaki

Reputation: 105

I put data in a Map and I get it in different order

I have a method where I read data from a DB, it goes like this:

public Collection<Map<String, String>> getAllFieldsValues() throws Exception
...
mapaTemp.put("DNI", dni.toString());
mapaTemp.put("NOMBRE", nombre.toString());
mapaTemp.put("APELLIDOS", apellidos.toString());
mapaTemp.put("CURSO", curso.toString());
mapaTemp.put("DIRECCION", direccion.toString());
allFieldsValues.add(mapaTemp);
...
return allFieldsValues;

Then I have another method to display the data in a JTable, but the problem is that I read it in a different order from what I put it, I read it in this order. DNI,DIRECCION,NOMBRE,APELLIDOS,CURSO.

This is a problem because when I display the data in the JTable it appears in wrong order. Anyone knows why can it be? Thanks!

Upvotes: 2

Views: 2405

Answers (2)

Kevin Bowersox
Kevin Bowersox

Reputation: 94489

Try using a LinkedHashMap

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

public class Test {
    public static void main(String[] args) {
        Map mapaTemp = new LinkedHashMap();

        // Add some elements
        mapaTemp.put("DNI", "1");
        mapaTemp.put("NOMBRE", "2");
        mapaTemp.put("APELLIDOS", "3");
        mapaTemp.put("CURSO", "4");
        mapaTemp.put("DIRECCION", "5");


        for (Iterator it = mapaTemp.keySet().iterator(); it.hasNext();) {
            Object key = it.next();
            Object value = mapaTemp.get(key);
            System.out.println(value);
        }

    }

}

Upvotes: 6

Kristian
Kristian

Reputation: 6613

What type is mapaTemp and how do you read the values from the map? For example a Java HashMap has no order so you cannot expect to get the results in insertion order.

You should be looking at a LinkedHashMap

Upvotes: 9

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