不使用数据库存储表数据的最佳方法？

Question

I need to store data from parsed XML , I have no problem with the parsing, that I can handle. The problem is that I receive a table data basically where each time the column names, columns number and the data it self are different. Now I don't want to use SQLite Database as I have a small number of entries and I don't see it feet for this situation. I even think I can't use it as I will have to create a new table for each data set I will receive. Now to be more clear here is some examples:

 <Details1_Collection>
    <Details1 ProductName="Bicycle" Units="2341" DefectedUnits="125" />
    <Details1 ProductName="Television" Units="3154" DefectedUnits="75" />
    <Details1 ProductName="Keyboard" Units="2413" DefectedUnits="12" />
    ...
  </Details1_Collection>

or another XML :

 <Details_Collection>
    <Details HireDate="2003-02-15T00:00:00" JobTitle="Chief Executive Officer"  BirthDate="1963-03-02T00:00:00" />
    <Details HireDate="2002-03-03T00:00:00" JobTitle="Vice President of Engineering" BirthDate="1965-09-01T00:00:00" />
    <Details HireDate="2001-12-12T00:00:00" JobTitle="Engineering Manager" BirthDate="1968-12- 13T00:00:00" />
    ...
 <Details_Collection>

Now you can notice that the XML tags are different: Details1_Collection and Details_Collection , Details1 and Details and I will receive a new tag set almost each time. But that is not a problem for me, because I receive them in a sooner call to the server so I know what tags I should parse. I don't need to store the Attributes as well names as I already have those too. I need to store only the values.

The Question:

How should I store the Attributes data which basically is a table data but It's a different table with different column names and number each time? I would prefer to not store this data as is as a String/Dom element inside of it's parent object but ratter to parse it into some java data structure that can be accessed easily on the UI thread.

In Short:

This data is a part of a bigger object and my goal is to parse it into some kind of data structure and attach it as part of the parent class.

Any help with that would be appreciated.

Answer 1

I have stumbled on the following forum post:

http://www.javaprogrammingforums.com/java-programming-tutorials/696-multi-dimension-arraylist-example.html

There is an implementation of ArrayList of ArrayLists, this is the code:

import java.util.ArrayList;

public class ArrayList2d<Type>
{
ArrayList<ArrayList<Type>>  array;

public ArrayList2d()
{
    array = new ArrayList<ArrayList<Type>>();
}

/**
 * ensures a minimum capacity of num rows. Note that this does not guarantee
 * that there are that many rows.
 * 
 * @param num
 */
public void ensureCapacity(int num)
{
    array.ensureCapacity(num);
}

/**
 * Ensures that the given row has at least the given capacity. Note that
 * this method will also ensure that getNumRows() >= row
 * 
 * @param row
 * @param num
 */
public void ensureCapacity(int row, int num)
{
    ensureCapacity(row);
    while (row < getNumRows())
    {
        array.add(new ArrayList<Type>());
    }
    array.get(row).ensureCapacity(num);
}

/**
 * Adds an item at the end of the specified row. This will guarantee that at least row rows exist.
 */
public void Add(Type data, int row)
{
    ensureCapacity(row);
    while(row >= getNumRows())
    {
        array.add(new ArrayList<Type>());
    }
    array.get(row).add(data);
}

public Type get(int row, int col)
{
    return array.get(row).get(col);
}

public void set(int row, int col, Type data)
{
    array.get(row).set(col,data);
}

public void remove(int row, int col)
{
    array.get(row).remove(col);
}

public boolean contains(Type data)
{
    for (int i = 0; i < array.size(); i++)
    {
        if (array.get(i).contains(data))
        {
            return true;
        }
    }
    return false;
}

public int getNumRows()
{
    return array.size();
}

public int getNumCols(int row)
{
    return array.get(row).size();
}
}

This is the best way I found by this moment to store the data I want to store. What do you think, Java experts?

Thanks.

Answer 2

Is there a reason you cannot perform the typical Java Serialization? As in, create classes that represent your data, let them implement Serializable , and just read and write the whole object graph to a file using Object(Input|Output)Stream s?

Keep in mind this only works if your whole object graph will fit into memory.