Java UTF8 File Read readUTF8(DataInput buf)

Description

Reads an UTF8 string from a byte buffer.

License

MIT License

Parameter

Parameter	Description
buf	The byte buffer to read from

Exception

Parameter	Description

Return

The read string

Declaration

public static String readUTF8(DataInput buf) throws IOException 

Method Source Code

//package com.java2s;
/*/*from  ww w. ja  va 2s  .  co m*/
 * This file is part of Flow Networking, licensed under the MIT License (MIT).
 *
 * Copyright (c) 2013 Spout LLC <http://www.spout.org/>
 *
 * 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.DataInput;

import java.io.IOException;
import java.nio.charset.StandardCharsets;

public class Main {
    /**
     * Reads an UTF8 string from a byte buffer.
     *
     * @param buf The byte buffer to read from
     * @return The read string
     * @throws java.io.IOException If the reading fails
     */
    public static String readUTF8(DataInput buf) throws IOException {
        // Read the string's length
        final int len = readVarInt(buf);
        final byte[] bytes = new byte[len];
        buf.readFully(bytes);
        return new String(bytes, StandardCharsets.UTF_8);
    }

    /**
     * Reads an integer written into the byte buffer as one of various bit sizes.
     *
     * @param buf The byte buffer to read from
     * @return The read integer
     * @throws java.io.IOException If the reading fails
     */
    public static int readVarInt(DataInput buf) throws IOException {
        int out = 0;
        int bytes = 0;
        byte in;
        while (true) {
            in = buf.readByte();
            out |= (in & 0x7F) << (bytes * 7);
            if (bytes > 32) {
                throw new IOException("Attempt to read int bigger than allowed for a varint!");
            }
            if ((in & 0x80) != 0x80) {
                break;
            }
        }
        return out;
    }
}

Related

1. readRawUTF8Bytes(final byte[] bytes)
2. readResourceUtf8(Class contextClass, String filename)
3. readStringFromUTF8Stream(InputStream is)
4. readStringUTF16LE(byte[] var0, int var1, int var2)
5. readTextFile(File inputFile)
6. readUtf8String(DataInputStream in)
7. readUTFByteArrayFromDataInput(final DataInput in)
8. utf8Reader(InputStream in)