StringUtil.java — netty Source File

Source Code

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.util.internal;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

import static io.netty.util.internal.ObjectUtil.*;

/**
 * String utility class.
 */
public final class StringUtil {

    public static final String EMPTY_STRING = "";
    public static final String NEWLINE = SystemPropertyUtil.get("line.separator", "\n");

    public static final char DOUBLE_QUOTE = '\"';
    public static final char COMMA = ',';
    public static final char LINE_FEED = '\n';
    public static final char CARRIAGE_RETURN = '\r';
    public static final char TAB = '\t';
    public static final char SPACE = 0x20;

    private static final String[] BYTE2HEX_PAD = new String[256];
    private static final String[] BYTE2HEX_NOPAD = new String[256];
    private static final byte[] HEX2B;

    /**
     * 2 - Quote character at beginning and end.
     * 5 - Extra allowance for anticipated escape characters that may be added.
     */
    private static final int CSV_NUMBER_ESCAPE_CHARACTERS = 2 + 5;
    private static final char PACKAGE_SEPARATOR_CHAR = '.';

    static {
        // Generate the lookup table that converts a byte into a 2-digit hexadecimal integer.
        for (int i = 0; i < BYTE2HEX_PAD.length; i++) {
            String str = Integer.toHexString(i);
            BYTE2HEX_PAD[i] = i > 0xf ? str : ('0' + str);
            BYTE2HEX_NOPAD[i] = str;
        }
        // Generate the lookup table that converts an hex char into its decimal value:
        // the size of the table is such that the JVM is capable of save any bounds-check
// ... (671 more lines)