A small Java library for dealing with International Bank Account Numbers (IBANs).

The IBAN class is intended for use in your domain types. IBAN objects enforce that their value is the correct length for its country code and that it passes checksum validation. The Modulo97 class exposes the checksum validation code for other purposes, such as live input validation.

Install

Grab a package from Github or get it from Maven Central:

Maven

    <dependency>
        <groupId>nl.garvelink.oss</groupId>
        <artifactId>iban</artifactId>
        <version>1.0.0</version>
    </dependency>

Gradle

    dependencies {
        compile 'nl.garvelink.oss:iban:1.0.0'
    }

Use

Obtain an IBAN instance using one of the static factory methods: valueOf( ) and parse( ). Methods throw java.lang.IllegalArgumentException on invalid input.

    // Obtain an instance of IBAN.
    IBAN iban = IBAN.valueOf( "NL91ABNA0417164300" );

    // toString() emits standard formatting, toPlainString() is compact.
    String s = iban.toString(); // "NL91 ABNA 0417 1643 00"
    String p = iban.toPlainString(); // "NL91ABNA0417164300"

    // Input may be formatted.
    iban = IBAN.valueOf( "BE68 5390 0754 7034" );

    // The valueOf() method returns null if its argument is null.
    iban.valueOf( null ); // null

    // The parse() method throws an exception if its argument is null.
    iban.parse( null ); // IllegalArgumentException

    // IBAN does not implement Comparable<T>, but a simple Comparator is provided.
    List<IBAN> ibans = getListOfIBANs();
    Collections.sort( ibans, IBAN.LEXICAL_ORDER );

    // The equals() and hashCode() methods are implemented.
    Map<IBAN, String> ibansAsKeys = Maps.newHashMap();
    ibansAsKeys.put( iban, "this is fine" );

    // You can use the Modulo97 class directly to compute or verify the check digits on an input.
    String candidate = "GB29 NWBK 6016 1331 9268 19";
    boolean valid = Modulo97.verifyCheckDigits( candidate ); // true

    // Modulo97 API methods take CharSequence, not just String.
    StringBuilder builder = new StringBuilder( "LU000019400644750000" );
    int checkDigits = Modulo97.calculateCheckDigits( builder ); // 28

    // Get the expected IBAN length for a country code:
    int length = IBAN.getLengthForCountryCode( "DK" );

Notes

• The length of an IBAN is checked against the required length for its country code. Other country-specific validation (e.g. national check digits) is absent.
• The IBAN class does not implement Serializable, because the string representation is a superior serialized form.

References

• http://en.wikipedia.org/wiki/IBAN
• http://www.ecbs.org/iban.htm

Copyright and License

Copyright 2013 Barend Garvelink

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.