A lightweight ISO8583 (is an international standard for financial transaction card originated interchange messaging - wikipedia ) library for Java and Android base on builder pattern and provide very simple use as you will see later.

• Supporting Blocking IO and Non-blocking IO (NIO)
• Supporting SSL/TLS
• Base on Builder pattern
• String not used for security reasons
• Lightweight ISO-8583 lib for java and android
• working with some enums, it's more readable
• no dependency

Library will be available at Maven Centeral so you can add this dependency to your pom.xml like below:

<dependency>
    <groupId>com.imohsenb</groupId>
    <artifactId>ISO8583</artifactId>
    <version>1.0.5</version>
</dependency>

or direct download from HERE

To create an ISO message you must use ISOMessageBuilder which produce iso message for you:

ISOMessage isoMessage = ISOMessageBuilder.Packer(VERSION.V1987)
                .networkManagement()
                .mti(MESSAGE_FUNCTION.Request, MESSAGE_ORIGIN.Acquirer)
                .processCode("920000")
                .setField(FIELDS.F11_STAN,  "1")
                .setField(FIELDS.F12_LocalTime,  "023120")
                .setField(FIELDS.F13_LocalDate,  "0332")
                .setField(FIELDS.F24_NII_FunctionCode,  "333")
                .setHeader("1002230000")
                .build();
                

with ISOMessageBuilder.Packer(VERSION.V1987) you can build iso message as you can see above. the 'Packer' method return 8 method for 8 iso message class (authorization, financial, networkManagment, ...) based on ISO8583 after that you can set message function and message origin by mti method. mti method accept string and enums as parameter, and I think enums are much clear and readable. As you know an iso message need a 'Processing Code' and you can set it's value by `processCode' method, and then we can start setting required fields by 'setField' method and accept String and enums as field number parameter. After all, you must call build method to generate iso message object.

For unpacking a buffer received from server you need to use ISOMessageBuilder.Unpacker():

ISOMessage isoMessage = ISOMessageBuilder.Unpacker()
                                    .setMessage(SAMPLE_HEADER + SAMPLE_MSG)
                                    .build();

ISOMessage object has multiple method provide fields, message body, header and ... for security reason they will return byte array exept .toString and .getStringField method, because Strings stay alive in memory until a garbage collector will come to collect that. but you can clear byte or char arrays after use and calling garbage collector is not important anymore. If you use Strings, taking memory dumps will be dangerous.

    byte[] body = isoMessage.getBody();

    byte[] trace = isoMessage.getField(11);

    String trace = isoMessage.getStringField(FIELDS.F11_STAN);

Sending message to iso server and received response from server can be done with ISOClient in many ways:

ISOClient client = ISOClientBuilder.createSocket(HOST, PORT)
                .build();

        client.connect();
        String response = Arrays.toString(client.sendMessageSync(new SampleIsoMessage()));
        System.out.println("response = " + response);
        client.disconnect();

Sending a message to ISO server over SSL/TLS is more complicated, especially with NIO methods. but I try to make it more simple and usefull:

ISOClient client = ISOClientBuilder.createSocket(HOST, PORT)
                                .enableSSL()
                                .setSSLProtocol("TLSv1.2")
                                .setKeyManagers(km.getKeyManagers())
                                .setTrustManagers(null)
                                .build();

it's enough to adding .enableSSL() and another requirement parameters before .build() and may you need to prepare KeyStore and another things before. TrustManagers can be null.

NIO (stands for non-blocking I/O) is a collection of Java programming language APIs that offer features for intensive I/O operations - wikipedia. It's so simple to use in this library just see below : 😎

ISOClient client = ISOClientBuilder.createSocket(HOST, PORT)
                .configureBlocking(false)
                .build();

😁😁‚ it's ready for use, with just set .configureBlocking to false. it is posibble to use with .enableSSL() too.

Copyright 2018 Mohsen Beiranvand

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

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