Java tutorial
package org.bouncycastle.asn1; import java.io.IOException; import org.bouncycastle.util.Arrays; import org.bouncycastle.util.Strings; /** * DER UTF8String object. */ public class DERUTF8String extends ASN1Primitive implements ASN1String { private final byte[] string; /** * Return an UTF8 string from the passed in object. * * @param obj a DERUTF8String or an object that can be converted into one. * @exception IllegalArgumentException * if the object cannot be converted. * @return a DERUTF8String instance, or null */ public static DERUTF8String getInstance(Object obj) { if (obj == null || obj instanceof DERUTF8String) { return (DERUTF8String) obj; } if (obj instanceof byte[]) { try { return (DERUTF8String) fromByteArray((byte[]) obj); } catch (Exception e) { throw new IllegalArgumentException("encoding error in getInstance: " + e.toString()); } } throw new IllegalArgumentException("illegal object in getInstance: " + obj.getClass().getName()); } /** * Return an UTF8 String from a tagged object. * * @param obj * the tagged object holding the object we want * @param explicit * true if the object is meant to be explicitly tagged false * otherwise. * @exception IllegalArgumentException * if the tagged object cannot be converted. * @return a DERUTF8String instance, or null */ public static DERUTF8String getInstance(ASN1TaggedObject obj, boolean explicit) { ASN1Primitive o = obj.getObject(); if (explicit || o instanceof DERUTF8String) { return getInstance(o); } else { return new DERUTF8String(ASN1OctetString.getInstance(o).getOctets()); } } /* * Basic constructor - byte encoded string. */ DERUTF8String(byte[] string) { this.string = string; } /** * Basic constructor * * @param string the string to be carried in the UTF8String object, */ public DERUTF8String(String string) { this.string = Strings.toUTF8ByteArray(string); } public String getString() { return Strings.fromUTF8ByteArray(string); } public String toString() { return getString(); } public int hashCode() { return Arrays.hashCode(string); } boolean asn1Equals(ASN1Primitive o) { if (!(o instanceof DERUTF8String)) { return false; } DERUTF8String s = (DERUTF8String) o; return Arrays.areEqual(string, s.string); } boolean isConstructed() { return false; } int encodedLength() throws IOException { return 1 + StreamUtil.calculateBodyLength(string.length) + string.length; } void encode(ASN1OutputStream out, boolean withTag) throws IOException { out.writeEncoded(withTag, BERTags.UTF8_STRING, string); } }