Java: Getting the properties of a class to construct a string representation

Let's say I have a class like this (and also further assume that all the private variables:

public class Item {
    private String _id = null;
    private String _name = null;
    private String _description = null;

        ...
}

Now, if I want to build a toString() representation of this class, I would do something like this inside the Item class:

@Override
public String toString() {
    return (_id + " " + _name + " " + _description);
}

But what if I have say 15 private variables inside the class? Do I have to write the name of each and every variable like this?

Ideally, I would like to get over with the task by iterating through the list of private variables of this class and construct the string representation:

@Override
public String toString() {
    ArrayList<String> members = getClass().getMembers(); //Some method like this
    String string = "";
    for(...)
        string += members[i] + " ";
}

Or perhaps a toJSON method, I would still need access to the names of these variables. Any suggestions?

Edit Report

-1

Starting from the good medopal answer, you can use this code to have a string representation of all fields of an object, even if you are outside its class (obviously it's only for fields with a getter method):

/**Gives a string representation of the fields of the object
 * @param obj the object
 * @return
 */
private static String objectToString(Object obj) {
    StringBuilder sb = new StringBuilder();
    try {
        Class c = Class.forName(obj.getClass().getName());
        Method m[] = c.getDeclaredMethods();

        Object oo;
        for (int i = 0; i < m.length; i++)
            if (m[i].getName().startsWith("get")) {
                oo = m[i].invoke(obj, null);
                sb.append(m[i].getName().substring(3) + "="
                        + String.valueOf(oo) + "\n");
            }
    } catch (Throwable e) {
        System.err.println(e);
    }
    return sb.toString();
}

answered 2010-12-06T17:01:35.900

Java: Getting the properties of a class to construct a string representation

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