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Proof of concept: how to dynamically select an available constructor using reflection in Java

I am developing a conceptual concept of (de-) serialization, ideally able to serialize any object and collect information about the class itself. I started implementing it with Reflection so that:

  • Access to type hierarchy (Superclasses, Interfaces, etc.)
  • Find all the fields of this object and get all the values ​​in these fields

Serialization is the "easy" part, and can be achieved by applying this rule recursively to the object until I find null or primitive types. Now that I'm stuck: deserialization.

Starting with a simple object, the string "Hello World", I have this serialization:

<object type="java.lang.String">
    <primitive name="count" type="int" value="11 />
    <primitive name="hash" type="int" value="0" />
    <primitive name="offset" type="int" value="0" />
    <array name="value" basetype="char">
        <value>H</value>
        <value>e</value>
        <value>l</value>
        ...
        <value>r</value>
        <value>l</value>
        <value>d</value>
    </array>
</object>

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<object class="some-class-with-no-default-constructor">
    <object name="some-attrib-name" class="attrib-1-class">
    <primitive name="size" type="int" value="5" />
...
</object>

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EDIT

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public final class A {
    private final Object o;
    private A(final Object o) { if (o == null) throw new Error(); this.o = o; }
    public static A a() { return new A(new Object()); }
    public Object getO() { return o; }
}

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private static Unsafe getUnsafe() throws Exception {
    Field vDeclaredField = Unsafe.class.getDeclaredFields()[0];
    vDeclaredField.setAccessible(true);
    Unsafe vUnsafe = (Unsafe) vDeclaredField.get(null);
    vDeclaredField.setAccessible(false);
    return vUnsafe;
}

public static void main(String[] args) throws Exception {
    A objectA = (A) getUnsafe().allocateInstance(A.class);

    Field fieldO = A.class.getDeclaredField("o");
    boolean oldAccessibilityValue = fieldO.isAccessible();
    fieldO.setAccessible(true);
    Object objectOParameter = Arrays.asList(1,2,3,4); //could be any object
    fieldO.set(objectA, objectOParameter);
    fieldO.setAccessible(oldAccessibilityValue); //I personally prefer setting it to old value

    assert(objectOParameter.equals(objectA.getO()));
}

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public final class A {
    private final Object o;
    private A(final Object o) { if (o == null) throw new Error(); this.o = o; }
    public static A a() { return new A(new Object()); }
    public Object getO() { return o; }
}

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class StockQuoteProvider {
    private QuoteCache cache;
    private Thread quoteCacheUpdater;
    public StockQuoteProvider() {
        this.quoteCacheUpdater = ... // sets up a Thread that will use sockets to connect to Yahoo stock quote provider and update the cache periodically
        this.quoteCacheUpdater.start();
    }
    public Quote getQuote(final String symbol) { return ... }
}

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// Represents a range of integers, {a, a+1, ..., b}, in which a < b.
class Range {
  private final Object lock = new Object();
  private int a;
  private int b;
  Range(final int a, final int b) { setAB(a, b); }
  final int[] getAB() { synchronized(lock) { return new int[]{a, b}; } }
  final void setAB(final int a, final int b) {
    if (!(a < b)) { throw new IllegalArgumentException("Invalid range"); }
    synchronized(lock) { this.a = a; this.b = b; }
  }
  @Override public String toString() {
    int[] ab = getAB();
    int a = ab[0];
    int b = ab[1];
    return a + " < " + b;
  }
}

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public class Test {
  public static Range r = null;
  public static void Main(final String[] args) {
    final Thread t1 = new Thread(new Runnable() {
      @Override void run() { r = deserialize(serialize(new Range(1, 3)); }
    });

    final Thread t2 = new Thread(new Runnable() {
      @Override void run() { System.out.println(r); }
    });

    t1.start();
    t2.start();
}

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