Encodes a string into Base64 format. - Java java.lang

Java examples for java.lang:String Base64

  1. HOME
  2. Java
  3. java.lang
  4. String Base64

Description

Encodes a string into Base64 format.

Demo Code


//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        String s = "java2s.com";
        System.out.println(encodeString(s));
    }//from w w w.j av  a 2 s .  co  m

    private static final char[] map1 = new char[64];

    /**
     * Encodes a string into Base64 format.
     * No blanks or line breaks are inserted.
     *
     * @param s A String to be encoded.
     * @return A String containing the Base64 encoded data.
     */
    public static String encodeString(String s) {
        return new String(encode(s.getBytes()));
    }

    /**
     * Encodes a byte array into Base64 format.
     * No blanks or line breaks are inserted in the output.
     *
     * @param in An array containing the data bytes to be encoded.
     * @return A character array containing the Base64 encoded data.
     */
    public static char[] encode(byte[] in) {
        return encode(in, 0, in.length);
    }

    /**
     * Encodes a byte array into Base64 format.
     * No blanks or line breaks are inserted in the output.
     *
     * @param in   An array containing the data bytes to be encoded.
     * @param iLen Number of bytes to process in <code>in</code>.
     * @return A character array containing the Base64 encoded data.
     */
    public static char[] encode(byte[] in, int iLen) {
        return encode(in, 0, iLen);
    }

    /**
     * Encodes a byte array into Base64 format.
     * No blanks or line breaks are inserted in the output.
     *
     * @param in   An array containing the data bytes to be encoded.
     * @param iOff Offset of the first byte in <code>in</code> to be processed.
     * @param iLen Number of bytes to process in <code>in</code>, starting at <code>iOff</code>.
     * @return A character array containing the Base64 encoded data.
     */
    public static char[] encode(byte[] in, int iOff, int iLen) {
        int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
        int oLen = ((iLen + 2) / 3) * 4; // output length including padding
        char[] out = new char[oLen];
        int ip = iOff;
        int iEnd = iOff + iLen;
        int op = 0;
        while (ip < iEnd) {
            int i0 = in[ip++] & 0xff;
            int i1 = ip < iEnd ? in[ip++] & 0xff : 0;
            int i2 = ip < iEnd ? in[ip++] & 0xff : 0;
            int o0 = i0 >>> 2;
            int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
            int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
            int o3 = i2 & 0x3F;
            out[op++] = map1[o0];
            out[op++] = map1[o1];
            out[op] = op < oDataLen ? map1[o2] : '=';
            op++;
            out[op] = op < oDataLen ? map1[o3] : '=';
            op++;
        }
        return out;
    }
}

Related Tutorials