http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
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package org.bouncycastle.cert.path;

import java.util.ArrayList;
import java.util.List;

import org.bouncycastle.util.Integers;

class CertPathValidationResultBuilder
{
    private final CertPathValidationContext context;
    private final List<Integer> certIndexes = new ArrayList<Integer>();
    private final List<Integer> ruleIndexes = new ArrayList<Integer>();
    private final List<CertPathValidationException> exceptions = new ArrayList<CertPathValidationException>();

    CertPathValidationResultBuilder(CertPathValidationContext context)
    {
        this.context = context;
    }

    public CertPathValidationResult build()
    {
        if (exceptions.isEmpty())
        {
            return new CertPathValidationResult(context);
        }
        else
        {
            return new CertPathValidationResult(context,
                toInts(certIndexes), toInts(ruleIndexes), (CertPathValidationException[])exceptions.toArray(new CertPathValidationException[exceptions.size()]));
        }
    }

    public void addException(int certIndex, int ruleIndex, CertPathValidationException exception)
    {
        this.certIndexes.add(Integers.valueOf(certIndex));
        this.ruleIndexes.add(Integers.valueOf(ruleIndex));
        this.exceptions.add(exception);
    }

    private int[] toInts(List<Integer> values)
    {
        int[] rv = new int[values.size()];

        for (int i = 0; i != rv.length; i++)
        {
            rv[i] = ((Integer)values.get(i)).intValue();
        }

        return rv;
    }
}