Major Description
How the built-in classes for persistent identity value encodes as itself as a String is critical/significant – because
a) the encoded string often is decoded to extract the original value for instance look up
b) for untyped persistence capable instances, the encoded string carries the actual class name – and hence is important to instantiate the actual instance during loading from database
Unfortunately, this important decision about encoding-decoding of identity value is not emphasized with methods such as encode()/decode() on OpenJPAId but encoding is done with ubiquitous Object.toString() and decoding is burried in code lines.
While it is perhaps important to review this scheme, the immediate issue at hand is somewhat narrower and as follows:
The root abstract class OpenJPAId has the following toString() implementation
public String toString()
The concrete implementation such as IntId or FloatId overwrites this behavior as follows:
IntId.java:
private final int key;
public String toString()
{ return String.valueOf(key); } FloatId.java:
private final float key;
public String toString()
Apart from the subtle difference (but why), they look to be following the same principle, i.e. just stringify the value.
But the interesting part is LongId does not have a toString() method.
Hence its toString() form is dictated by its abstract super class OpenJPAId which appends the class name with a dash character to the actual long value of the identity.
I can not figure out the reason of this anomaly for long identifier as opposed to other Short/Integer or Float etc.
The risk of simply adding a toString() to LongId that is in line with other id types, of course, a) breaking any existing application that may be assuming the previous encoding
b) the unknown original reason behind not overwriting LongId.toString() method
Can someone please, please answer/shed some light?
It is critical for some direction I am pursuing to support generic/templated types where exact types are not determinable at compile/design time.
Without an answer, I will commit the change on LongId to have a toString() method.
+
+ public String toString()