# iso-8583-packer

**Repository Path**: jarkata/iso-8583-packer

## Basic Information

- **Project Name**: iso-8583-packer
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-01-22
- **Last Updated**: 2024-01-23

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Module `iso-8583-packer`

The module is a library for creation, packing and unpacking ISO 8583 messages,
and also for messages in non-standard formats.

## Usage

The module is the source of the `iso-8583-packer-1.0.50` library.

The library can be loaded from
the [Maven Central Repository](https://mvnrepository.com/artifact/com.credibledoc/iso-8583-packer).

Example of Maven configuration in a `pom.xml` file

    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    
        ... some mandatory tags omitted
    
        <dependencies>
            <dependency>
                <groupId>cn.jarkata</groupId>
                <artifactId>iso-8583-packer</artifactId>
                <version>1.0.50</version>
            </dependency>
        </dependencies>
    
    </project>

## Examples

### Fixed - length value without a tag

The code below will create a new instance of
the [FieldBuilder](https://gitee.com/jarkata/iso-8583-packer/blob/master/src/main/java/com/credibledoc/iso8583packer/FieldBuilder.java)
with a single field.
The field will contain 2 bytes data in [BCD](https://en.wikipedia.org/wiki/Binary-coded_decimal) format.

```Java
         FieldBuilder.builder(MsgFieldType.VAL)
        .defineLen(2)
        .defineBodyPacker(BcdBodyPacker.leftPadding0());
```

The field can be filled with data
by [ValueHolder](https://gitee.com/jarkata/iso-8583-packer/blob/master/src/main/java/com/credibledoc/iso8583packer/ValueHolder.java),
for example:

```Java
            String value="123";
        ValueHolder valueHolder=
        ValueHolder.newInstance(fieldBuilder.getCurrentField())
        .setValue(value);
```

The filled object can be packed into bytes

```Java
            byte[]valueBytes=valueHolder.pack();
        String bytesHex=HexService.bytesToHex(valueBytes);
        assertEquals("0123",bytesHex);
```

The defined MsgField can be used for unpacking from bytes to an object

```Java
            String packedHex="0456";
        byte[]packedBytes=HexService.hex2byte(packedHex);

        MsgValue msgValue=
        ValueHolder.newInstance(fieldBuilder.getCurrentField())
        .unpack(packedBytes);
        String unpackedValue=(String)msgValue.getBodyValue();

        String expectedValue="456";
        assertEquals(expectedValue,unpackedValue);
```

You can find the complete example
here: BcdBodyPackerTest

More complex message definition with inner subfields is described in the [complex-example.md](doc/complex-example.md)
document.

## Field types

Every field contains a header (optional) and a body (mandatory), for example <b>02 01 03</b>, where

* <b>02</b> is header `TAG`
* <b>01</b> is header `LEN`
* <b>03</b> is body `VAL`

The [FieldBuilder](https://github.com/credibledoc/credible-doc/blob/master/iso-8583-packer/src/main/java/com/credibledoc/iso8583packer/FieldBuilder.java)
is able to create different field types, with and without headers, see the [field-types.md](doc/field-types.md)
document.

### `TAG` types and packers

The following page [tag-packer.md](doc/tag/tag-packer.md) describes some formats and types of `TAG` packers.

### `LEN` types and packers

The following [length-packer.md](doc/length/length-packer.md) page describes different `LEN` subfield types
and implementations of the `LengthPacker` interface.

### `VAL` types and packers

The following page [body-packer.md](doc/body/body-packer.md) contains description of different formats of body values.

### Masker

In a production environment it is necessary to mask private sensitive data before print it to a log file.
The following page [masker.md](doc/masking/masker.md) describes how to mask the data.

### Bitmap

The ISO 8583 standard uses [Bitmaps](https://en.wikipedia.org/wiki/ISO_8583#Bitmaps) for defining of field numbers
placed on a message.

The following [bitmap-packer.md](doc/bitmap/bitmap-packer.md) page describes how to define and use bitmaps.

## Repeated fields

In some cases is required to repeat some values in messages, for example to send multiple products purchased by a
customer.

The following example [repeated-tag-val.md](doc/repeated/repeated-tag-val.md)
explains how to pack and unpack multiple recurrent fields.