ISOStringFieldPackager throws an IndexOutOfBoundsException

[MouslihAbdelhakim]

Hello,

While Unpacking a DE with IFE_LLLCHAR today this exception was thrown

Exception in thread "main" org.jpos.iso.ISOException: org.jpos.iso.IFE_LLLCHAR: Problem unpacking field 61 (java.lang.IndexOutOfBoundsException) unpacking field=61, consumed=241

After some investigating, it turned out that the DE value was signaling that it has a length of a 100 but in reality it was only 26 bytes in length.

Since java.lang.IndexOutOfBoundsException does not tell us much, i think that it would be useful if ISOStringFieldPackager compared how many bytes are still array to how much it is expecting to extract and threw a more comprehensive error message like :

Trying to extract X bytes but the message contains only Y bytes

I will gladly work on this issue if the JPos project accepts PRs.

kind regards.

[ar]

Anything that saves us debugging time with this kind of very common issues while configuring new endpoints is welcome, so please go ahead with the PR at your convenience.