Java Text File Write nio writeString(OutputStream buffer, String s)

Description

write String

License

Open Source License

Declaration

public static void writeString(OutputStream buffer, String s) throws IOException

Method Source Code


//package com.java2s;
/* //from  w  w w  .  j  a  v a  2  s  .com
 * Copyright (c) 2016 acmi
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

public class Main {
    private static Charset defaultCharset = Charset.forName("ascii");
    private static CharsetEncoder defaultEncoder = defaultCharset.newEncoder();
    private static Charset utf16leCharset = Charset.forName("utf-16le");

    public static void writeString(OutputStream buffer, String s) throws IOException {
        if (s == null || s.isEmpty()) {
            writeCompactInt(buffer, 0);
            return;
        }

        s += '\0';
        boolean def = defaultEncoder.canEncode(s);
        byte[] bytes = s.getBytes(def ? defaultCharset : utf16leCharset);
        writeCompactInt(buffer, def ? bytes.length : -bytes.length / 2);
        buffer.write(bytes);
    }

    public static void writeCompactInt(OutputStream output, int value) throws IOException {
        output.write(compactIntToByteArray(value));
    }

    public static byte[] compactIntToByteArray(int v) {
        boolean negative = v < 0;
        v = Math.abs(v);
        int[] bytes = new int[] { (v) & 0b00111111, (v >> 6) & 0b01111111, (v >> 6 + 7) & 0b01111111,
                (v >> 6 + 7 + 7) & 0b01111111, (v >> 6 + 7 + 7 + 7) & 0b01111111 };

        if (negative)
            bytes[0] |= 0b10000000;

        int size = 5;
        for (int i = 4; i > 0; i--) {
            if (bytes[i] != 0)
                break;
            size--;
        }
        byte[] res = new byte[size];

        for (int i = 0; i < size; i++) {
            if (i != size - 1)
                bytes[i] |= i == 0 ? 0b01000000 : 0b10000000;
            res[i] = (byte) bytes[i];
        }
        return res;
    }
}

Java Text File Write nio writeString(OutputStream buffer, String s)

Description

License

Declaration

Method Source Code

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