Java example source code file (StringTypes.java)

This example Java source code file (StringTypes.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bmp, derinputstream, deroutputstream, dervalue, exception, fileinputstream, fileoutputstream, ia5, printable, problem, string, t61, unicodebigunmarked, utf8

The StringTypes.java Java example source code

/*
 * Copyright (c) 1999, 2001, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 4178326
 * @summary Make sure reading/writing of different DER encoded string
 * types works correctly.
 */

import java.io.*;
import sun.security.util.*;

public class StringTypes {

    private static String s = null;
    private static String fileName = "StringTypes.bin";

    public static void main(String[] args) throws Exception {

        s = new String("This is just a test!");

        byte[] asciiBytes = s.getBytes("ASCII");
        byte[] utf8Bytes = s.getBytes("UTF8");
        byte[] iso8859_1Bytes = s.getBytes("ISO-8859-1");

        byte[] unicodeBytes = s.getBytes("UnicodeBigUnmarked");
        byte[] unicodeBytes2 = getBytes(s);

        // test that unicode encoder is the correct one
        if (!equalBytes(unicodeBytes, unicodeBytes2))
          throw new Exception ("Problem with unicode encoder being used.");

        FileOutputStream fout = new FileOutputStream(fileName);
        DerOutputStream derOut = new DerOutputStream();

        System.out.println("Writing Java string out as various DER" +
                           " encoded Strings now...");
        derOut.putUTF8String(s);
        derOut.putPrintableString(s);
        derOut.putIA5String(s);
        derOut.putT61String(s);
        derOut.putBMPString(s);

        derOut.derEncode(fout);
        fout.close();

        FileInputStream fis = new FileInputStream(fileName);
        byte[] data = new byte[fis.available()];
        fis.read(data);
        DerInputStream derIn = new DerInputStream(data);
        fis.close();

        System.out.println("\nReading Strings back as DerValue's...\n");

        DerValue der;

        der = derIn.getDerValue();
        verifyDER("UTF8", der, DerValue.tag_UTF8String, utf8Bytes);

        der = derIn.getDerValue();
        verifyDER("Printable", der, DerValue.tag_PrintableString, asciiBytes);

        der = derIn.getDerValue();
        verifyDER("IA5", der, DerValue.tag_IA5String, asciiBytes);

        der = derIn.getDerValue();
        verifyDER("T61", der, DerValue.tag_T61String, iso8859_1Bytes);

        der = derIn.getDerValue();
        verifyDER("BMP", der, DerValue.tag_BMPString, unicodeBytes);

        if (derIn.available() > 0)
          throw new Exception("DerInputStream has extra data!");


        derIn.reset();

        System.out.println("Reading Strings back as Strings...\n");

        verifyString("UTF8", derIn.getUTF8String());
        verifyString("Printable", derIn.getPrintableString());
        verifyString("IA5", derIn.getIA5String());
        verifyString("T61", derIn.getT61String());
        verifyString("BMP", derIn.getBMPString());

    }

    /**
     * Return the unicode bytes in the string as a byte[]
     */
    private static byte[] getBytes(String s) {

        int len = s.length();
        byte[] retVal = new byte[len*2]; // each unicode char is two bytes

        for (int i = 0, j = 0; i < len; i++, j+=2) {
            retVal[j]   = (byte) (s.charAt(i)>>8);
            retVal[j+1] = (byte) (s.charAt(i));
        }

        return retVal;
    }

    /* Compare two byte arrays */
    private static boolean equalBytes(byte[] a, byte[] b) {

        int len1 = a.length;
        int len2 = b.length;

        if (len1 != len2)
            return false;

        for (int i = 0; i < len1 && i < len2; i++)
            if (a[i] != b[i])
                return false;

        return true;
    }

    /* Verify that the DER object is correct */
    private static void verifyDER(String type,
                                  DerValue der, byte tag,
                                  byte[] data) throws Exception {
        if (der.tag != tag)
            throw new Exception("Problem with tag for " + type);

        if (!equalBytes(der.data.toByteArray(), data))
            throw new Exception("Problem with data for " + type);

        System.out.println(type + " checks out OK");
        System.out.println("Calling toString on it: " + der.toString() + "\n");
    }

    private static void verifyString(String type, String str)
        throws Exception {

        if (!s.equals(str))
            throw new Exception("Problem with string " + type);

        System.out.println(type + "String checks out OK\n");
    }

}