Java tutorial
package org.bouncycastle.asn1.cms; import org.bouncycastle.asn1.ASN1EncodableVector; import org.bouncycastle.asn1.ASN1Object; import org.bouncycastle.asn1.ASN1Primitive; import org.bouncycastle.asn1.ASN1Set; import org.bouncycastle.asn1.ASN1TaggedObject; import org.bouncycastle.asn1.DLSet; /** * <a href="http://tools.ietf.org/html/rfc5652">RFC 5652</a> defines * 5 "SET OF Attribute" entities with 5 different names. * This is common implementation for them all: * <pre> * SignedAttributes ::= SET SIZE (1..MAX) OF Attribute * UnsignedAttributes ::= SET SIZE (1..MAX) OF Attribute * UnprotectedAttributes ::= SET SIZE (1..MAX) OF Attribute * AuthAttributes ::= SET SIZE (1..MAX) OF Attribute * UnauthAttributes ::= SET SIZE (1..MAX) OF Attribute * * Attributes ::= * SET SIZE(1..MAX) OF Attribute * </pre> */ public class Attributes extends ASN1Object { private ASN1Set attributes; private Attributes(ASN1Set set) { attributes = set; } public Attributes(ASN1EncodableVector v) { attributes = new DLSet(v); } /** * Return an Attribute set object from the given object. * <p> * Accepted inputs: * <ul> * <li> null → null * <li> {@link Attributes} object * <li> {@link org.bouncycastle.asn1.ASN1Set#getInstance(java.lang.Object) ASN1Set} input formats with Attributes structure inside * </ul> * * @param obj the object we want converted. * @exception IllegalArgumentException if the object cannot be converted. */ public static Attributes getInstance(Object obj) { if (obj instanceof Attributes) { return (Attributes) obj; } else if (obj != null) { return new Attributes(ASN1Set.getInstance(obj)); } return null; } public static Attributes getInstance(ASN1TaggedObject obj, boolean explicit) { return getInstance(ASN1Set.getInstance(obj, explicit)); } public Attribute[] getAttributes() { Attribute[] rv = new Attribute[attributes.size()]; for (int i = 0; i != rv.length; i++) { rv[i] = Attribute.getInstance(attributes.getObjectAt(i)); } return rv; } /** * Produce an object suitable for an ASN1OutputStream. */ public ASN1Primitive toASN1Primitive() { return attributes; } }