Recently doing a project, we used the 8583 agreement. Stepped on many pits, the project has been on the line, write a blog about some of the ways the most recently used record summary.
(A) introduces the 8583 agreement, (ii) the use of summary Java are two ways to achieve 8583.
Please see the need to code directly (two), but I suggest you take a look at (a), to learn more about knowing the total no harm.
1.8583 Introduction
8583 protocol is based on packet communications protocol ISO8583 international standard packet format, the 8583 package of up to 128 field domains, each domain has a unified and fixed-length and variable-length divided. 8583 packet bitmap preceding paragraph, it is determined key in place of packing and unpacking field domain. 8583 agreement on development of multi-use POS machines. ( Excerpt from Baidu Encyclopedia explanation ) packets in 8583, with a place in the form of domain transfer. Is different from ordinary json, json is key = value form, and the two sides agreed 8583 is good, what is the meaning of each field, which were then filled domain value. 8583 The format is generally composed of three parts, the header information, and bitmap fields.
2.8583 introduce structure
Structure 8583: packet length (4 bytes can be set according to their protocol) header + (+ TPDU may be a message identifier, etc., generally 4 bytes, so if the TPDU plus 10 bytes or more, and the protocol set their own) + bitmap (8 bytes, if domain representation 128, this field per 16 bytes) data + actual data, typically data in hexadecimal notation. Note that this only usually means is that, will vary according to the actual situation. 8583 up to 128 domains, each domain has a unified and fixed-length and variable-length divided. What is a fixed-length, variable length what is it? White said fixed length is a fixed length, variable length becomes long. Each domain is a fixed length or longer, there will be described in the domain. Explain, there are a lot of companies use the 8583 agreement, in fact, it is a pseudo-8583 agreement, meaning that the use of the 8583 agreement, but inside they use the actual domain of 8583 is very different, so everyone please pay attention.
Packet length, etc. This is generally the rear portion of the length divided by the post good fight calculated, i.e. the length of the packet header length + + actual bitmap data, this is in the 4 + 8 (16) + data.length () /2. Note that if the hexadecimal representation, then that is two bytes one behind us a detailed example. Suppose we calculated length is 42, then four bytes is 0042,16 notation is 30,303,432. Here I use to 0042.
Header portion, the fixed portion are in general, assumed to be only 4 bytes message types, such as represented by 1000 of the message transaction type, 1200 represents the type of packet refund etc., should it actually represents 30, 31 is 31303030 323030.
(Temporarily write so today, if pressing for information, you can contact the talk in detail.)