private List intersection()

in maven-artifact/src/main/java/org/apache/maven/artifact/versioning/VersionRange.java [307:454]
135 lines of code
28 McCabe index (conditional complexity)

    private List intersection( List r1, List r2 )
    {
        List restrictions = new ArrayList( r1.size() + r2.size() );
        Iterator i1 = r1.iterator();
        Iterator i2 = r2.iterator();
        Restriction res1 = (Restriction) i1.next();
        Restriction res2 = (Restriction) i2.next();

        boolean done = false;
        while ( !done )
        {
            if ( res1.getLowerBound() == null || res2.getUpperBound() == null
                || res1.getLowerBound().compareTo( res2.getUpperBound() ) <= 0 )
            {
                if ( res1.getUpperBound() == null || res2.getLowerBound() == null
                    || res1.getUpperBound().compareTo( res2.getLowerBound() ) >= 0 )
                {
                    ArtifactVersion lower;
                    ArtifactVersion upper;
                    boolean lowerInclusive;
                    boolean upperInclusive;

                    // overlaps
                    if ( res1.getLowerBound() == null )
                    {
                        lower = res2.getLowerBound();
                        lowerInclusive = res2.isLowerBoundInclusive();
                    }
                    else if ( res2.getLowerBound() == null )
                    {
                        lower = res1.getLowerBound();
                        lowerInclusive = res1.isLowerBoundInclusive();
                    }
                    else
                    {
                        int comparison = res1.getLowerBound().compareTo( res2.getLowerBound() );
                        if ( comparison < 0 )
                        {
                            lower = res2.getLowerBound();
                            lowerInclusive = res2.isLowerBoundInclusive();
                        }
                        else if ( comparison == 0 )
                        {
                            lower = res1.getLowerBound();
                            lowerInclusive = res1.isLowerBoundInclusive() && res2.isLowerBoundInclusive();
                        }
                        else
                        {
                            lower = res1.getLowerBound();
                            lowerInclusive = res1.isLowerBoundInclusive();
                        }
                    }

                    if ( res1.getUpperBound() == null )
                    {
                        upper = res2.getUpperBound();
                        upperInclusive = res2.isUpperBoundInclusive();
                    }
                    else if ( res2.getUpperBound() == null )
                    {
                        upper = res1.getUpperBound();
                        upperInclusive = res1.isUpperBoundInclusive();
                    }
                    else
                    {
                        int comparison = res1.getUpperBound().compareTo( res2.getUpperBound() );
                        if ( comparison < 0 )
                        {
                            upper = res1.getUpperBound();
                            upperInclusive = res1.isUpperBoundInclusive();
                        }
                        else if ( comparison == 0 )
                        {
                            upper = res1.getUpperBound();
                            upperInclusive = res1.isUpperBoundInclusive() && res2.isUpperBoundInclusive();
                        }
                        else
                        {
                            upper = res2.getUpperBound();
                            upperInclusive = res2.isUpperBoundInclusive();
                        }
                    }

                    // don't add if they are equal and one is not inclusive
                    if ( lower == null || upper == null || lower.compareTo( upper ) != 0 )
                    {
                        restrictions.add( new Restriction( lower, lowerInclusive, upper, upperInclusive ) );
                    }
                    else if ( lowerInclusive && upperInclusive )
                    {
                        restrictions.add( new Restriction( lower, lowerInclusive, upper, upperInclusive ) );
                    }

                    //noinspection ObjectEquality
                    if ( upper == res2.getUpperBound() )
                    {
                        // advance res2
                        if ( i2.hasNext() )
                        {
                            res2 = (Restriction) i2.next();
                        }
                        else
                        {
                            done = true;
                        }
                    }
                    else
                    {
                        // advance res1
                        if ( i1.hasNext() )
                        {
                            res1 = (Restriction) i1.next();
                        }
                        else
                        {
                            done = true;
                        }
                    }
                }
                else
                {
                    // move on to next in r1
                    if ( i1.hasNext() )
                    {
                        res1 = (Restriction) i1.next();
                    }
                    else
                    {
                        done = true;
                    }
                }
            }
            else
            {
                // move on to next in r2
                if ( i2.hasNext() )
                {
                    res2 = (Restriction) i2.next();
                }
                else
                {
                    done = true;
                }
            }
        }

        return restrictions;
    }